Question: What is Troubleshooting with kubectl?

Answer: I n   M o d u l e   2 ,   y o u   u s e d   t h e   k u b e c t l   c o m m a n d - l i n e   i n t e r f a c e .   Y o u ' l l   c o n t i n u e   t o   u s e   i t   i n   M o d u l e   3   t o   g e t   i n f o r m a t i o n   a b o u t   d e p l o y e d   a p p l i c a t i o n s   a n d   t h e i r   e n v i r o n m e n t s .   T h e   m o s t   c o m m o n   o p e r a t i o n s   c a n   b e   d o n e   w i t h   t h e   f o l l o w i n g   k u b e c t l   s u b c o m m a n d s :   k u b e c t l   g e t   -   l i s t   r e s o u r c e s k u b e c t l   d e s c r i b e   -   s h o w   d e t a i l e d   i n f o r m a t i o n   a b o u t   a   r e s o u r c e k u b e c t l   l o g s   -   p r i n t   t h e   l o g s   f r o m   a   c o n t a i n e r   i n   a   p o d k u b e c t l   e x e c   -   e x e c u t e   a   c o m m a n d   o n   a   c o n t a i n e r   i n   a   p o d   Y o u   c a n   u s e   t h e s e   c o m m a n d s   t o   s e e   w h e n   a p p l i c a t i o n s   w e r e   d e p l o y e d ,   w h a t   t h e i r   c u r r e n t   s t a t u s e s   a r e ,   w h e r e   t h e y   a r e   r u n n i n g   a n d   w h a t   t h e i r   c o n f i g u r a t i o n s   a r e .   N o w   t h a t   w e   k n o w   m o r e   a b o u t   o u r   c l u s t e r   c o m p o n e n t s   a n d   t h e   c o m m a n d   l i n e ,   l e t ' s   e x p l o r e   o u r   a p p l i c a t i o n .


Question: What is Check application configuration?

Answer: L e t ' s   v e r i f y   t h a t   t h e   a p p l i c a t i o n   w e   d e p l o y e d   i n   t h e   p r e v i o u s   s c e n a r i o   i s   r u n n i n g .   W e ' l l   u s e   t h e   k u b e c t l   g e t   c o m m a n d   a n d   l o o k   f o r   e x i s t i n g   P o d s :   k u b e c t l   g e t   p o d s   I f   n o   p o d s   a r e   r u n n i n g ,   p l e a s e   w a i t   a   c o u p l e   o f   s e c o n d s   a n d   l i s t   t h e   P o d s   a g a i n .   Y o u   c a n   c o n t i n u e   o n c e   y o u   s e e   o n e   P o d   r u n n i n g .   N e x t ,   t o   v i e w   w h a t   c o n t a i n e r s   a r e   i n s i d e   t h a t   P o d   a n d   w h a t   i m a g e s   a r e   u s e d   t o   b u i l d   t h o s e   c o n t a i n e r s   w e   r u n   t h e   k u b e c t l   d e s c r i b e   p o d s   c o m m a n d :   k u b e c t l   d e s c r i b e   p o d s   W e   s e e   h e r e   d e t a i l s   a b o u t   t h e   P o d ’ s   c o n t a i n e r :   I P   a d d r e s s ,   t h e   p o r t s   u s e d   a n d   a   l i s t   o f   e v e n t s   r e l a t e d   t o   t h e   l i f e c y c l e   o f   t h e   P o d .   T h e   o u t p u t   o f   t h e   d e s c r i b e   s u b c o m m a n d   i s   e x t e n s i v e   a n d   c o v e r s   s o m e   c o n c e p t s   t h a t   w e   d i d n ’ t   e x p l a i n   y e t ,   b u t   d o n ’ t   w o r r y ,   t h e y   w i l l   b e c o m e   f a m i l i a r   b y   t h e   e n d   o f   t h i s   t u t o r i a l .


Question: What is Show the app in the terminal?

Answer: R e c a l l   t h a t   P o d s   a r e   r u n n i n g   i n   a n   i s o l a t e d ,   p r i v a t e   n e t w o r k   -   s o   w e   n e e d   t o   p r o x y   a c c e s s   t o   t h e m   s o   w e   c a n   d e b u g   a n d   i n t e r a c t   w i t h   t h e m .   T o   d o   t h i s ,   w e ' l l   u s e   t h e   k u b e c t l   p r o x y   c o m m a n d   t o   r u n   a   p r o x y   i n   a   s e c o n d   t e r m i n a l .   O p e n   a   n e w   t e r m i n a l   w i n d o w ,   a n d   i n   t h a t   n e w   t e r m i n a l ,   r u n :   k u b e c t l   p r o x y   N o w   a g a i n ,   w e ' l l   g e t   t h e   P o d   n a m e   a n d   q u e r y   t h a t   p o d   d i r e c t l y   t h r o u g h   t h e   p r o x y .   T o   g e t   t h e   P o d   n a m e   a n d   s t o r e   i t   i n   t h e   P O D _ N A M E   e n v i r o n m e n t   v a r i a b l e :   e x p o r t   P O D _ N A M E = " $ ( k u b e c t l   g e t   p o d s   - o   g o - t e m p l a t e   - - t e m p l a t e   ' { { r a n g e   . i t e m s } } { { . m e t a d a t a . n a m e } } { { " \ n " } } { { e n d } } ' ) "   e c h o   N a m e   o f   t h e   P o d :   $ P O D _ N A M E   T o   s e e   t h e   o u t p u t   o f   o u r   a p p l i c a t i o n ,   r u n   a   c u r l   r e q u e s t :   c u r l   h t t p : / / l o c a l h o s t : 8 0 0 1 / a p i / v 1 / n a m e s p a c e s / d e f a u l t / p o d s / $ P O D _ N A M E : 8 0 8 0 / p r o x y /   T h e   U R L   i s   t h e   r o u t e   t o   t h e   A P I   o f   t h e   P o d .


Question: What is Executing commands on the container?

Answer: W e   c a n   e x e c u t e   c o m m a n d s   d i r e c t l y   o n   t h e   c o n t a i n e r   o n c e   t h e   P o d   i s   u p   a n d   r u n n i n g .   F o r   t h i s ,   w e   u s e   t h e   e x e c   s u b c o m m a n d   a n d   u s e   t h e   n a m e   o f   t h e   P o d   a s   a   p a r a m e t e r .   L e t ’ s   l i s t   t h e   e n v i r o n m e n t   v a r i a b l e s :   k u b e c t l   e x e c   " $ P O D _ N A M E "   - -   e n v   A g a i n ,   i t ' s   w o r t h   m e n t i o n i n g   t h a t   t h e   n a m e   o f   t h e   c o n t a i n e r   i t s e l f   c a n   b e   o m i t t e d   s i n c e   w e   o n l y   h a v e   a   s i n g l e   c o n t a i n e r   i n   t h e   P o d .   N e x t   l e t ’ s   s t a r t   a   b a s h   s e s s i o n   i n   t h e   P o d ’ s   c o n t a i n e r :   k u b e c t l   e x e c   - t i   $ P O D _ N A M E   - -   b a s h   W e   h a v e   n o w   a n   o p e n   c o n s o l e   o n   t h e   c o n t a i n e r   w h e r e   w e   r u n   o u r   N o d e J S   a p p l i c a t i o n .   T h e   s o u r c e   c o d e   o f   t h e   a p p   i s   i n   t h e   s e r v e r . j s   f i l e :   c a t   s e r v e r . j s   Y o u   c a n   c h e c k   t h a t   t h e   a p p l i c a t i o n   i s   u p   b y   r u n n i n g   a   c u r l   c o m m a n d :   c u r l   h t t p : / / l o c a l h o s t : 8 0 8 0


Question: What is Note:?

Answer: T o   c l o s e   y o u r   c o n t a i n e r   c o n n e c t i o n ,   t y p e   e x i t .


Question: What is What's next?

Answer: T u t o r i a l   U s i n g   A   S e r v i c e   T o   E x p o s e   Y o u r   A p p . L e a r n   m o r e   a b o u t   P o d s . L e a r n   m o r e   a b o u t   N o d e s .


Question: What is MutatingWebhookConfiguration?

Answer: MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1import "k8s.io/api/admissionregistration/v1"MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1kind: MutatingWebhookConfigurationmetadata (ObjectMeta)Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata.webhooks ([]MutatingWebhook)Patch strategy: merge on key nameMap: unique values on key name will be kept during a mergeWebhooks is a list of webhooks and the affected resources and operations.MutatingWebhook describes an admission webhook and the resources and operations it applies to.webhooks.admissionReviewVersions ([]string), requiredAtomic: will be replaced during a mergeAdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.webhooks.clientConfig (WebhookClientConfig), requiredClientConfig defines how to communicate with the hook. RequiredWebhookClientConfig contains the information to make a TLS connection with the webhookwebhooks.clientConfig.caBundle ([]byte)caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.webhooks.clientConfig.service (ServiceReference)service is a reference to the service for this webhook. Either service or url must be specified.If the webhook is running within the cluster, then you should use service.ServiceReference holds a reference to Service.legacy.k8s.iowebhooks.clientConfig.service.name (string), requiredname is the name of the service. Requiredwebhooks.clientConfig.service.namespace (string), requirednamespace is the namespace of the service. Requiredwebhooks.clientConfig.service.path (string)path is an optional URL path which will be sent in any request to this service.webhooks.clientConfig.service.port (int32)If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).webhooks.clientConfig.url (string)url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in


Question: How does MutatingWebhookConfiguration work?

Answer: MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1import "k8s.io/api/admissionregistration/v1"MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1kind: MutatingWebhookConfigurationmetadata (ObjectMeta)Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata.webhooks ([]MutatingWebhook)Patch strategy: merge on key nameMap: unique values on key name will be kept during a mergeWebhooks is a list of webhooks and the affected resources and operations.MutatingWebhook describes an admission webhook and the resources and operations it applies to.webhooks.admissionReviewVersions ([]string), requiredAtomic: will be replaced during a mergeAdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.webhooks.clientConfig (WebhookClientConfig), requiredClientConfig defines how to communicate with the hook. RequiredWebhookClientConfig contains the information to make a TLS connection with the webhookwebhooks.clientConfig.caBundle ([]byte)caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.webhooks.clientConfig.service (ServiceReference)service is a reference to the service for this webhook. Either service or url must be specified.If the webhook is running within the cluster, then you should use service.ServiceReference holds a reference to Service.legacy.k8s.iowebhooks.clientConfig.service.name (string), requiredname is the name of the service. Requiredwebhooks.clientConfig.service.namespace (string), requirednamespace is the namespace of the service. Requiredwebhooks.clientConfig.service.path (string)path is an optional URL path which will be sent in any request to this service.webhooks.clientConfig.service.port (int32)If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).webhooks.clientConfig.url (string)url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in


Question: When would you use MutatingWebhookConfiguration?

Answer: MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1import "k8s.io/api/admissionregistration/v1"MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1kind: MutatingWebhookConfigurationmetadata (ObjectMeta)Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata.webhooks ([]MutatingWebhook)Patch strategy: merge on key nameMap: unique values on key name will be kept during a mergeWebhooks is a list of webhooks and the affected resources and operations.MutatingWebhook describes an admission webhook and the resources and operations it applies to.webhooks.admissionReviewVersions ([]string), requiredAtomic: will be replaced during a mergeAdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.webhooks.clientConfig (WebhookClientConfig), requiredClientConfig defines how to communicate with the hook. RequiredWebhookClientConfig contains the information to make a TLS connection with the webhookwebhooks.clientConfig.caBundle ([]byte)caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.webhooks.clientConfig.service (ServiceReference)service is a reference to the service for this webhook. Either service or url must be specified.If the webhook is running within the cluster, then you should use service.ServiceReference holds a reference to Service.legacy.k8s.iowebhooks.clientConfig.service.name (string), requiredname is the name of the service. Requiredwebhooks.clientConfig.service.namespace (string), requirednamespace is the namespace of the service. Requiredwebhooks.clientConfig.service.path (string)path is an optional URL path which will be sent in any request to this service.webhooks.clientConfig.service.port (int32)If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).webhooks.clientConfig.url (string)url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in


Question: What are the benefits of MutatingWebhookConfiguration?

Answer: MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1import "k8s.io/api/admissionregistration/v1"MutatingWebhookConfigurationMutatingWebhookConfiguration describes the configuration of and admission webhook that accept or reject and may change the object.apiVersion: admissionregistration.k8s.io/v1kind: MutatingWebhookConfigurationmetadata (ObjectMeta)Standard object metadata; More info: https://git.k8s.io/community/contributors/devel/sig-architecture/api-conventions.md#metadata.webhooks ([]MutatingWebhook)Patch strategy: merge on key nameMap: unique values on key name will be kept during a mergeWebhooks is a list of webhooks and the affected resources and operations.MutatingWebhook describes an admission webhook and the resources and operations it applies to.webhooks.admissionReviewVersions ([]string), requiredAtomic: will be replaced during a mergeAdmissionReviewVersions is an ordered list of preferred AdmissionReview versions the Webhook expects. API server will try to use first version in the list which it supports. If none of the versions specified in this list supported by API server, validation will fail for this object. If a persisted webhook configuration specifies allowed versions and does not include any versions known to the API Server, calls to the webhook will fail and be subject to the failure policy.webhooks.clientConfig (WebhookClientConfig), requiredClientConfig defines how to communicate with the hook. RequiredWebhookClientConfig contains the information to make a TLS connection with the webhookwebhooks.clientConfig.caBundle ([]byte)caBundle is a PEM encoded CA bundle which will be used to validate the webhook's server certificate. If unspecified, system trust roots on the apiserver are used.webhooks.clientConfig.service (ServiceReference)service is a reference to the service for this webhook. Either service or url must be specified.If the webhook is running within the cluster, then you should use service.ServiceReference holds a reference to Service.legacy.k8s.iowebhooks.clientConfig.service.name (string), requiredname is the name of the service. Requiredwebhooks.clientConfig.service.namespace (string), requirednamespace is the namespace of the service. Requiredwebhooks.clientConfig.service.path (string)path is an optional URL path which will be sent in any request to this service.webhooks.clientConfig.service.port (int32)If specified, the port on the service that hosting webhook. Default to 443 for backward compatibility. port should be a valid port number (1-65535, inclusive).webhooks.clientConfig.url (string)url gives the location of the webhook, in standard URL form (scheme://host:port/path). Exactly one of url or service must be specified.The host should not refer to a service running in the cluster; use the service field instead. The host might be resolved via external DNS in


Question: What is MutatingWebhookConfiguration?

Answer: a p i V e r s i o n :   a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1   i m p o r t   " k 8 s . i o / a p i / a d m i s s i o n r e g i s t r a t i o n / v 1 "


Question: What is MutatingWebhookConfiguration?

Answer: M u t a t i n g W e b h o o k C o n f i g u r a t i o n   d e s c r i b e s   t h e   c o n f i g u r a t i o n   o f   a n d   a d m i s s i o n   w e b h o o k   t h a t   a c c e p t   o r   r e j e c t   a n d   m a y   c h a n g e   t h e   o b j e c t .   a p i V e r s i o n :   a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 k i n d :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n m e t a d a t a   ( O b j e c t M e t a ) S t a n d a r d   o b j e c t   m e t a d a t a ;   M o r e   i n f o :   h t t p s : / / g i t . k 8 s . i o / c o m m u n i t y / c o n t r i b u t o r s / d e v e l / s i g - a r c h i t e c t u r e / a p i - c o n v e n t i o n s . m d # m e t a d a t a . w e b h o o k s   ( [ ] M u t a t i n g W e b h o o k ) P a t c h   s t r a t e g y :   m e r g e   o n   k e y   n a m e M a p :   u n i q u e   v a l u e s   o n   k e y   n a m e   w i l l   b e   k e p t   d u r i n g   a   m e r g e W e b h o o k s   i s   a   l i s t   o f   w e b h o o k s   a n d   t h e   a f f e c t e d   r e s o u r c e s   a n d   o p e r a t i o n s . M u t a t i n g W e b h o o k   d e s c r i b e s   a n   a d m i s s i o n   w e b h o o k   a n d   t h e   r e s o u r c e s   a n d   o p e r a t i o n s   i t   a p p l i e s   t o . w e b h o o k s . a d m i s s i o n R e v i e w V e r s i o n s   ( [ ] s t r i n g ) ,   r e q u i r e d A t o m i c :   w i l l   b e   r e p l a c e d   d u r i n g   a   m e r g e A d m i s s i o n R e v i e w V e r s i o n s   i s   a n   o r d e r e d   l i s t   o f   p r e f e r r e d   A d m i s s i o n R e v i e w   v e r s i o n s   t h e   W e b h o o k   e x p e c t s .   A P I   s e r v e r   w i l l   t r y   t o   u s e   f i r s t   v e r s i o n   i n   t h e   l i s t   w h i c h   i t   s u p p o r t s .   I f   n o n e   o f   t h e   v e r s i o n s   s p e c i f i e d   i n   t h i s   l i s t   s u p p o r t e d   b y   A P I   s e r v e r ,   v a l i d a t i o n   w i l l   f


Question: What is MutatingWebhookConfigurationList?

Answer: M u t a t i n g W e b h o o k C o n f i g u r a t i o n L i s t   i s   a   l i s t   o f   M u t a t i n g W e b h o o k C o n f i g u r a t i o n .   a p i V e r s i o n :   a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 k i n d :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n L i s t m e t a d a t a   ( L i s t M e t a ) S t a n d a r d   l i s t   m e t a d a t a .   M o r e   i n f o :   h t t p s : / / g i t . k 8 s . i o / c o m m u n i t y / c o n t r i b u t o r s / d e v e l / s i g - a r c h i t e c t u r e / a p i - c o n v e n t i o n s . m d # t y p e s - k i n d s i t e m s   ( [ ] M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) ,   r e q u i r e d L i s t   o f   M u t a t i n g W e b h o o k C o n f i g u r a t i o n .   a p i V e r s i o n :   a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1   k i n d :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n L i s t   m e t a d a t a   ( L i s t M e t a )   S t a n d a r d   l i s t   m e t a d a t a .   M o r e   i n f o :   h t t p s : / / g i t . k 8 s . i o / c o m m u n i t y / c o n t r i b u t o r s / d e v e l / s i g - a r c h i t e c t u r e / a p i - c o n v e n t i o n s . m d # t y p e s - k i n d s   i t e m s   ( [ ] M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) ,   r e q u i r e d   L i s t   o f   M u t a t i n g W e b h o o k C o n f i g u r a t i o n .


Question: What is HTTP Request?

Answer: G E T   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s / { n a m e }


Question: What is Parameters?

Answer: n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y   n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d   n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y


Question: What is Response?

Answer: 2 0 0   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   O K   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: G E T   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s


Question: What is Parameters?

Answer: a l l o w W a t c h B o o k m a r k s   ( i n   q u e r y ) :   b o o l e a n a l l o w W a t c h B o o k m a r k s c o n t i n u e   ( i n   q u e r y ) :   s t r i n g c o n t i n u e f i e l d S e l e c t o r   ( i n   q u e r y ) :   s t r i n g f i e l d S e l e c t o r l a b e l S e l e c t o r   ( i n   q u e r y ) :   s t r i n g l a b e l S e l e c t o r l i m i t   ( i n   q u e r y ) :   i n t e g e r l i m i t p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y r e s o u r c e V e r s i o n   ( i n   q u e r y ) :   s t r i n g r e s o u r c e V e r s i o n r e s o u r c e V e r s i o n M a t c h   ( i n   q u e r y ) :   s t r i n g r e s o u r c e V e r s i o n M a t c h s e n d I n i t i a l E v e n t s   ( i n   q u e r y ) :   b o o l e a n s e n d I n i t i a l E v e n t s t i m e o u t S e c o n d s   ( i n   q u e r y ) :   i n t e g e r t i m e o u t S e c o n d s w a t c h   ( i n   q u e r y ) :   b o o l e a n w a t c h   a l l o w W a t c h B o o k m a r k s   ( i n   q u e r y ) :   b o o l e a n   a l l o w W a t c h B o o k m a r k s   c o n t i n u e   ( i n   q u e r y ) :   s t r i n g   c o n t i n u e   f i e l d S e l e c t o r   ( i n   q u e r y ) :   s t r i n g   f i e l d S e l e c t o r   l a b e l S e l e c t o r   ( i n   q u e r y ) :   s t r i n g   l a b e l S e l e c t o r   l i m i t   ( i n   q u e r y ) :   i n t e g e r   l i m i t   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y   r e s o u r c e V e r s i o n   ( i n   q u e r y ) :   s t r i n g   r e s o u r c e V e r s i o n   r e s o u r c e V e r s i o n M a t c h   ( i n   q u e r y ) :   s t r i n g   r e s o u r c e V e r s i o n M a t c h   s e n d I n i t i a l E v e n t s   ( i n   q u e r y ) :   b o o l e a n   s e n d I n i t i a l E v e n t s   t i m e o u t S e c o n d s   ( i n   q u e r y ) :   i n t e g e r   t i m e o u t S e c o n d s   w a t c h   ( i n   q u e r y ) :   b o o l e a n   w a t c h


Question: What is Response?

Answer: 2 0 0   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n L i s t ) :   O K   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: P O S T   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s


Question: What is Parameters?

Answer: b o d y :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n ,   r e q u i r e d d r y R u n   ( i n   q u e r y ) :   s t r i n g d r y R u n f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g f i e l d M a n a g e r f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g f i e l d V a l i d a t i o n p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y   b o d y :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n ,   r e q u i r e d   d r y R u n   ( i n   q u e r y ) :   s t r i n g   d r y R u n   f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g   f i e l d M a n a g e r   f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g   f i e l d V a l i d a t i o n   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y


Question: What is Response?

Answer: 2 0 0   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   O K   2 0 1   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   C r e a t e d   2 0 2   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   A c c e p t e d   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: P U T   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s / { n a m e }


Question: What is Parameters?

Answer: n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n b o d y :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n ,   r e q u i r e d d r y R u n   ( i n   q u e r y ) :   s t r i n g d r y R u n f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g f i e l d M a n a g e r f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g f i e l d V a l i d a t i o n p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y   n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d   n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n   b o d y :   M u t a t i n g W e b h o o k C o n f i g u r a t i o n ,   r e q u i r e d   d r y R u n   ( i n   q u e r y ) :   s t r i n g   d r y R u n   f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g   f i e l d M a n a g e r   f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g   f i e l d V a l i d a t i o n   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y


Question: What is Response?

Answer: 2 0 0   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   O K   2 0 1   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   C r e a t e d   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: P A T C H   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s / { n a m e }


Question: What is Parameters?

Answer: n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n b o d y :   P a t c h ,   r e q u i r e d d r y R u n   ( i n   q u e r y ) :   s t r i n g d r y R u n f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g f i e l d M a n a g e r f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g f i e l d V a l i d a t i o n f o r c e   ( i n   q u e r y ) :   b o o l e a n f o r c e p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y   n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d   n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n   b o d y :   P a t c h ,   r e q u i r e d   d r y R u n   ( i n   q u e r y ) :   s t r i n g   d r y R u n   f i e l d M a n a g e r   ( i n   q u e r y ) :   s t r i n g   f i e l d M a n a g e r   f i e l d V a l i d a t i o n   ( i n   q u e r y ) :   s t r i n g   f i e l d V a l i d a t i o n   f o r c e   ( i n   q u e r y ) :   b o o l e a n   f o r c e   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y


Question: What is Response?

Answer: 2 0 0   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   O K   2 0 1   ( M u t a t i n g W e b h o o k C o n f i g u r a t i o n ) :   C r e a t e d   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: D E L E T E   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s / { n a m e }


Question: What is Parameters?

Answer: n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n b o d y :   D e l e t e O p t i o n s d r y R u n   ( i n   q u e r y ) :   s t r i n g d r y R u n g r a c e P e r i o d S e c o n d s   ( i n   q u e r y ) :   i n t e g e r g r a c e P e r i o d S e c o n d s i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   ( i n   q u e r y ) :   b o o l e a n i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y p r o p a g a t i o n P o l i c y   ( i n   q u e r y ) :   s t r i n g p r o p a g a t i o n P o l i c y   n a m e   ( i n   p a t h ) :   s t r i n g ,   r e q u i r e d   n a m e   o f   t h e   M u t a t i n g W e b h o o k C o n f i g u r a t i o n   b o d y :   D e l e t e O p t i o n s   d r y R u n   ( i n   q u e r y ) :   s t r i n g   d r y R u n   g r a c e P e r i o d S e c o n d s   ( i n   q u e r y ) :   i n t e g e r   g r a c e P e r i o d S e c o n d s   i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   ( i n   q u e r y ) :   b o o l e a n   i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   p r e t t y   ( i n   q u e r y ) :   s t r i n g   p r e t t y   p r o p a g a t i o n P o l i c y   ( i n   q u e r y ) :   s t r i n g   p r o p a g a t i o n P o l i c y


Question: What is Response?

Answer: 2 0 0   ( S t a t u s ) :   O K   2 0 2   ( S t a t u s ) :   A c c e p t e d   4 0 1 :   U n a u t h o r i z e d


Question: What is HTTP Request?

Answer: D E L E T E   / a p i s / a d m i s s i o n r e g i s t r a t i o n . k 8 s . i o / v 1 / m u t a t i n g w e b h o o k c o n f i g u r a t i o n s


Question: What is Parameters?

Answer: b o d y :   D e l e t e O p t i o n s c o n t i n u e   ( i n   q u e r y ) :   s t r i n g c o n t i n u e d r y R u n   ( i n   q u e r y ) :   s t r i n g d r y R u n f i e l d S e l e c t o r   ( i n   q u e r y ) :   s t r i n g f i e l d S e l e c t o r g r a c e P e r i o d S e c o n d s   ( i n   q u e r y ) :   i n t e g e r g r a c e P e r i o d S e c o n d s i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   ( i n   q u e r y ) :   b o o l e a n i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l l a b e l S e l e c t o r   ( i n   q u e r y ) :   s t r i n g l a b e l S e l e c t o r l i m i t   ( i n   q u e r y ) :   i n t e g e r l i m i t p r e t t y   ( i n   q u e r y ) :   s t r i n g p r e t t y p r o p a g a t i o n P o l i c y   ( i n   q u e r y ) :   s t r i n g p r o p a g a t i o n P o l i c y r e s o u r c e V e r s i o n   ( i n   q u e r y ) :   s t r i n g r e s o u r c e V e r s i o n r e s o u r c e V e r s i o n M a t c h   ( i n   q u e r y ) :   s t r i n g r e s o u r c e V e r s i o n M a t c h s e n d I n i t i a l E v e n t s   ( i n   q u e r y ) :   b o o l e a n s e n d I n i t i a l E v e n t s t i m e o u t S e c o n d s   ( i n   q u e r y ) :   i n t e g e r t i m e o u t S e c o n d s   b o d y :   D e l e t e O p t i o n s   c o n t i n u e   ( i n   q u e r y ) :   s t r i n g   c o n t i n u e   d r y R u n   ( i n   q u e r y ) :   s t r i n g   d r y R u n   f i e l d S e l e c t o r   ( i n   q u e r y ) :   s t r i n g   f i e l d S e l e c t o r   g r a c e P e r i o d S e c o n d s   ( i n   q u e r y ) :   i n t e g e r   g r a c e P e r i o d S e c o n d s   i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   ( i n   q u e r y ) :   b o o l e a n   i g n o r e S t o r e R e a d E r r o r W i t h C l u s t e r B r e a k i n g P o t e n t i a l   l a b e l S e l e c t o r   (


Question: What is Response?

Answer: 2 0 0   ( S t a t u s ) :   O K   4 0 1 :   U n a u t h o r i z e d   T h i s   p a g e   i s   a u t o m a t i c a l l y   g e n e r a t e d .   I f   y o u   p l a n   t o   r e p o r t   a n   i s s u e   w i t h   t h i s   p a g e ,   m e n t i o n   t h a t   t h e   p a g e   i s   a u t o - g e n e r a t e d   i n   y o u r   i s s u e   d e s c r i p t i o n .   T h e   f i x   m a y   n e e d   t o   h a p p e n   e l s e w h e r e   i n   t h e   K u b e r n e t e s   p r o j e c t .


Question: What is kubectl?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information at: https://kubernetes.io/docs/reference/kubectl/kubectl [flags] Options--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--as-uid stringUID to impersonate for the operation.--cache-dir string Default: "$HOME/.kube/cache"Default cache directory--certificate-authority stringPath to a cert file for the certificate authority--client-certificate stringPath to a client certificate file for TLS--client-key stringPath to a client key file for TLS--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--disable-compressionIf true, opt-out of response compression for all requests to the server-h, --helphelp for kubectl--insecure-skip-tls-verifyIf true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure--kubeconfig stringPath to the kubeconfig file to use for CLI requests.--kuberc stringPath to the kuberc file to use for preferences. This can be disabled by exporting KUBECTL_KUBERC=false feature gate or turning off the feature KUBERC=off.--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--password stringPassword for basic authentication to the API server--profile string Default: "none"Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)--profile-output string Default: "profile.pprof"Name of the file to write the profile to--request-timeout string Default: "0"The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.-s, --server stringThe address and port of the Kubernetes API server--storage-driver-buffer-duration duration Default: 1m0sWrites in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction--storage-driver-db string Default: "cadvisor"database name--storage-driver-host string Default: "localhost:8086"database host:port--storage-driver-password string Default: "root"database password--storage-driver-secureuse secure connection with database--storage-driver-table string Default: "stats"table name--storage-driver-user string Default: "root"database username--tls-server-name stringServer name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used--token stringBearer token for authentication to the API server--user stringThe name of the kubeconfig user to use--username stringUsername for basic authentication to the API server--version version[=true]--version, --version=raw prints version information and qu


Question: How does kubectl work?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information at: https://kubernetes.io/docs/reference/kubectl/kubectl [flags] Options--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--as-uid stringUID to impersonate for the operation.--cache-dir string Default: "$HOME/.kube/cache"Default cache directory--certificate-authority stringPath to a cert file for the certificate authority--client-certificate stringPath to a client certificate file for TLS--client-key stringPath to a client key file for TLS--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--disable-compressionIf true, opt-out of response compression for all requests to the server-h, --helphelp for kubectl--insecure-skip-tls-verifyIf true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure--kubeconfig stringPath to the kubeconfig file to use for CLI requests.--kuberc stringPath to the kuberc file to use for preferences. This can be disabled by exporting KUBECTL_KUBERC=false feature gate or turning off the feature KUBERC=off.--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--password stringPassword for basic authentication to the API server--profile string Default: "none"Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)--profile-output string Default: "profile.pprof"Name of the file to write the profile to--request-timeout string Default: "0"The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.-s, --server stringThe address and port of the Kubernetes API server--storage-driver-buffer-duration duration Default: 1m0sWrites in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction--storage-driver-db string Default: "cadvisor"database name--storage-driver-host string Default: "localhost:8086"database host:port--storage-driver-password string Default: "root"database password--storage-driver-secureuse secure connection with database--storage-driver-table string Default: "stats"table name--storage-driver-user string Default: "root"database username--tls-server-name stringServer name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used--token stringBearer token for authentication to the API server--user stringThe name of the kubeconfig user to use--username stringUsername for basic authentication to the API server--version version[=true]--version, --version=raw prints version information and qu


Question: When would you use kubectl?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information at: https://kubernetes.io/docs/reference/kubectl/kubectl [flags] Options--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--as-uid stringUID to impersonate for the operation.--cache-dir string Default: "$HOME/.kube/cache"Default cache directory--certificate-authority stringPath to a cert file for the certificate authority--client-certificate stringPath to a client certificate file for TLS--client-key stringPath to a client key file for TLS--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--disable-compressionIf true, opt-out of response compression for all requests to the server-h, --helphelp for kubectl--insecure-skip-tls-verifyIf true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure--kubeconfig stringPath to the kubeconfig file to use for CLI requests.--kuberc stringPath to the kuberc file to use for preferences. This can be disabled by exporting KUBECTL_KUBERC=false feature gate or turning off the feature KUBERC=off.--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--password stringPassword for basic authentication to the API server--profile string Default: "none"Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)--profile-output string Default: "profile.pprof"Name of the file to write the profile to--request-timeout string Default: "0"The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.-s, --server stringThe address and port of the Kubernetes API server--storage-driver-buffer-duration duration Default: 1m0sWrites in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction--storage-driver-db string Default: "cadvisor"database name--storage-driver-host string Default: "localhost:8086"database host:port--storage-driver-password string Default: "root"database password--storage-driver-secureuse secure connection with database--storage-driver-table string Default: "stats"table name--storage-driver-user string Default: "root"database username--tls-server-name stringServer name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used--token stringBearer token for authentication to the API server--user stringThe name of the kubeconfig user to use--username stringUsername for basic authentication to the API server--version version[=true]--version, --version=raw prints version information and qu


Question: What are the benefits of kubectl?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information at: https://kubernetes.io/docs/reference/kubectl/kubectl [flags] Options--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--as-uid stringUID to impersonate for the operation.--cache-dir string Default: "$HOME/.kube/cache"Default cache directory--certificate-authority stringPath to a cert file for the certificate authority--client-certificate stringPath to a client certificate file for TLS--client-key stringPath to a client key file for TLS--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--disable-compressionIf true, opt-out of response compression for all requests to the server-h, --helphelp for kubectl--insecure-skip-tls-verifyIf true, the server's certificate will not be checked for validity. This will make your HTTPS connections insecure--kubeconfig stringPath to the kubeconfig file to use for CLI requests.--kuberc stringPath to the kuberc file to use for preferences. This can be disabled by exporting KUBECTL_KUBERC=false feature gate or turning off the feature KUBERC=off.--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--password stringPassword for basic authentication to the API server--profile string Default: "none"Name of profile to capture. One of (none|cpu|heap|goroutine|threadcreate|block|mutex)--profile-output string Default: "profile.pprof"Name of the file to write the profile to--request-timeout string Default: "0"The length of time to wait before giving up on a single server request. Non-zero values should contain a corresponding time unit (e.g. 1s, 2m, 3h). A value of zero means don't timeout requests.-s, --server stringThe address and port of the Kubernetes API server--storage-driver-buffer-duration duration Default: 1m0sWrites in the storage driver will be buffered for this duration, and committed to the non memory backends as a single transaction--storage-driver-db string Default: "cadvisor"database name--storage-driver-host string Default: "localhost:8086"database host:port--storage-driver-password string Default: "root"database password--storage-driver-secureuse secure connection with database--storage-driver-table string Default: "stats"table name--storage-driver-user string Default: "root"database username--tls-server-name stringServer name to use for server certificate validation. If it is not provided, the hostname used to contact the server is used--token stringBearer token for authentication to the API server--user stringThe name of the kubeconfig user to use--username stringUsername for basic authentication to the API server--version version[=true]--version, --version=raw prints version information and qu


Question: What is Synopsis?

Answer: k u b e c t l   c o n t r o l s   t h e   K u b e r n e t e s   c l u s t e r   m a n a g e r .   F i n d   m o r e   i n f o r m a t i o n   a t :   h t t p s : / / k u b e r n e t e s . i o / d o c s / r e f e r e n c e / k u b e c t l /   k u b e c t l   [ f l a g s ]


Question: What is Options?

Answer: U s e r n a m e   t o   i m p e r s o n a t e   f o r   t h e   o p e r a t i o n .   U s e r   c o u l d   b e   a   r e g u l a r   u s e r   o r   a   s e r v i c e   a c c o u n t   i n   a   n a m e s p a c e .   G r o u p   t o   i m p e r s o n a t e   f o r   t h e   o p e r a t i o n ,   t h i s   f l a g   c a n   b e   r e p e a t e d   t o   s p e c i f y   m u l t i p l e   g r o u p s .   U I D   t o   i m p e r s o n a t e   f o r   t h e   o p e r a t i o n .   D e f a u l t   c a c h e   d i r e c t o r y   P a t h   t o   a   c e r t   f i l e   f o r   t h e   c e r t i f i c a t e   a u t h o r i t y   P a t h   t o   a   c l i e n t   c e r t i f i c a t e   f i l e   f o r   T L S   P a t h   t o   a   c l i e n t   k e y   f i l e   f o r   T L S   T h e   n a m e   o f   t h e   k u b e c o n f i g   c l u s t e r   t o   u s e   T h e   n a m e   o f   t h e   k u b e c o n f i g   c o n t e x t   t o   u s e   I f   t r u e ,   o p t - o u t   o f   r e s p o n s e   c o m p r e s s i o n   f o r   a l l   r e q u e s t s   t o   t h e   s e r v e r   h e l p   f o r   k u b e c t l   I f   t r u e ,   t h e   s e r v e r ' s   c e r t i f i c a t e   w i l l   n o t   b e   c h e c k e d   f o r   v a l i d i t y .   T h i s   w i l l   m a k e   y o u r   H T T P S   c o n n e c t i o n s   i n s e c u r e   P a t h   t o   t h e   k u b e c o n f i g   f i l e   t o   u s e   f o r   C L I   r e q u e s t s .   P a t h   t o   t h e   k u b e r c   f i l e   t o   u s e   f o r   p r e f e r e n c e s .   T h i s   c a n   b e   d i s a b l e d   b y   e x p o r t i n g   K U B E C T L _ K U B E R C = f a l s e   f e a t u r e   g a t e   o r   t u r n i n g   o f f   t h e   f e a t u r e   K U B E R C = o f f .   R e q u i r e   s e r v e r   v e r s i o n   t o   m a t c h   c l i e n t   v e r s i o n   I f   p r e s e n t ,   t h e   n a m e s p a c e   s c o p e   f o r   t h i s   C L I   r e q u e s t   P a s s w o r d   f o r


Question: What is See Also?

Answer: k u b e c t l   a n n o t a t e   -   U p d a t e   t h e   a n n o t a t i o n s   o n   a   r e s o u r c e k u b e c t l   a p i - r e s o u r c e s   -   P r i n t   t h e   s u p p o r t e d   A P I   r e s o u r c e s   o n   t h e   s e r v e r k u b e c t l   a p i - v e r s i o n s   -   P r i n t   t h e   s u p p o r t e d   A P I   v e r s i o n s   o n   t h e   s e r v e r ,   i n   t h e   f o r m   o f   " g r o u p / v e r s i o n " k u b e c t l   a p p l y   -   A p p l y   a   c o n f i g u r a t i o n   t o   a   r e s o u r c e   b y   f i l e   n a m e   o r   s t d i n k u b e c t l   a t t a c h   -   A t t a c h   t o   a   r u n n i n g   c o n t a i n e r k u b e c t l   a u t h   -   I n s p e c t   a u t h o r i z a t i o n k u b e c t l   a u t o s c a l e   -   A u t o - s c a l e   a   d e p l o y m e n t ,   r e p l i c a   s e t ,   s t a t e f u l   s e t ,   o r   r e p l i c a t i o n   c o n t r o l l e r k u b e c t l   c e r t i f i c a t e   -   M o d i f y   c e r t i f i c a t e   r e s o u r c e s k u b e c t l   c l u s t e r - i n f o   -   D i s p l a y   c l u s t e r   i n f o r m a t i o n k u b e c t l   c o m p l e t i o n   -   O u t p u t   s h e l l   c o m p l e t i o n   c o d e   f o r   t h e   s p e c i f i e d   s h e l l   ( b a s h ,   z s h ,   f i s h ,   o r   p o w e r s h e l l ) k u b e c t l   c o n f i g   -   M o d i f y   k u b e c o n f i g   f i l e s k u b e c t l   c o r d o n   -   M a r k   n o d e   a s   u n s c h e d u l a b l e k u b e c t l   c p   -   C o p y   f i l e s   a n d   d i r e c t o r i e s   t o   a n d   f r o m   c o n t a i n e r s k u b e c t l   c r e a t e   -   C r e a t e   a   r e s o u r c e   f r o m   a   f i l e   o r   f r o m   s t d i n k u b e c t l   d e b u g   -   C r e a t e   d e b u g g i n g   s e s s i o n s   f o r   t r o u b l e s h o o t i n g   w o r k l o a d s   a n d   n o d e s k u b e c t l   d e l e t e   -   D e l e t e   r e s o u


Question: What is Cluster Administration?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Cluster AdministrationLower-level detail relevant to creating or administering a Kubernetes cluster.1: Node Shutdowns2: Swap memory management3: Node Autoscaling4: Certificates5: Cluster Networking6: Admission Webhook Good Practices7: Good practices for Dynamic Resource Allocation as a Cluster Admin8: Logging Architecture9: Compatibility Version For Kubernetes Control Plane Components10: Metrics For Kubernetes System Components11: Metrics for Kubernetes Object States12: System Logs13: Traces For Kubernetes System Components14: Proxies in Kubernetes15: API Priority and Fairness16: Installing Addons17: Coordinated Leader ElectionThe cluster administration overview is for anyone creating or administering a Kubernetes cluster. It assumes some familiarity with core Kubernetes concepts.Planning a clusterSee the guides in Setup for examples of how to plan, set up, and configure Kubernetes clusters. The solutions listed in this article are called distros.Note:Not all distros are actively maintained. Choose distros which have been tested with a recent version of Kubernetes.Before choosing a guide, here are some considerations:Do you want to try out Kubernetes on your computer, or do you want to build a high-availability, multi-node cluster? Choose distros best suited for your needs.Will you be using a hosted Kubernetes cluster, such as Google Kubernetes Engine, or hosting your own cluster?Will your cluster be on-premises, or in the cloud (IaaS)? Kubernetes does not directly support hybrid clusters. Instead, you can set up multiple clusters.If you are configuring Kubernetes on-premises, consider which networking model fits best.Will you be running Kubernetes on "bare metal" hardware or on virtual machines (VMs)?Do you want to run a cluster, or do you expect to do active development of Kubernetes project code? If the latter, choose an actively-developed distro. Some distros only use binary releases, but offer a greater variety of choices.Familiarize yourself with the components needed to run a cluster.Managing a clusterLearn how to manage nodes.Read about Node autoscaling.Learn how to set up and manage the resource quota for shared clusters.Securing a clusterGenerate Certificates describes the steps to generate certificates using different tool chains.Kubernetes Container Environment describes the environment for Kubelet managed containers on a Kubernetes node.Controlling Access to the Kubernetes API describes how Kubernetes implements access control for its own API.Authenticating explains authentication in Kubernetes, including the various authentication options.Authorization is separate from authentication, and controls how HTTP calls are handled.Using Admission Controllers explains plug-ins which intercepts requests to the Kubernetes API server after authentication and authorization.Admission Webhook Good Practices provides good practices an


Question: How does Cluster Administration work?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Cluster AdministrationLower-level detail relevant to creating or administering a Kubernetes cluster.1: Node Shutdowns2: Swap memory management3: Node Autoscaling4: Certificates5: Cluster Networking6: Admission Webhook Good Practices7: Good practices for Dynamic Resource Allocation as a Cluster Admin8: Logging Architecture9: Compatibility Version For Kubernetes Control Plane Components10: Metrics For Kubernetes System Components11: Metrics for Kubernetes Object States12: System Logs13: Traces For Kubernetes System Components14: Proxies in Kubernetes15: API Priority and Fairness16: Installing Addons17: Coordinated Leader ElectionThe cluster administration overview is for anyone creating or administering a Kubernetes cluster. It assumes some familiarity with core Kubernetes concepts.Planning a clusterSee the guides in Setup for examples of how to plan, set up, and configure Kubernetes clusters. The solutions listed in this article are called distros.Note:Not all distros are actively maintained. Choose distros which have been tested with a recent version of Kubernetes.Before choosing a guide, here are some considerations:Do you want to try out Kubernetes on your computer, or do you want to build a high-availability, multi-node cluster? Choose distros best suited for your needs.Will you be using a hosted Kubernetes cluster, such as Google Kubernetes Engine, or hosting your own cluster?Will your cluster be on-premises, or in the cloud (IaaS)? Kubernetes does not directly support hybrid clusters. Instead, you can set up multiple clusters.If you are configuring Kubernetes on-premises, consider which networking model fits best.Will you be running Kubernetes on "bare metal" hardware or on virtual machines (VMs)?Do you want to run a cluster, or do you expect to do active development of Kubernetes project code? If the latter, choose an actively-developed distro. Some distros only use binary releases, but offer a greater variety of choices.Familiarize yourself with the components needed to run a cluster.Managing a clusterLearn how to manage nodes.Read about Node autoscaling.Learn how to set up and manage the resource quota for shared clusters.Securing a clusterGenerate Certificates describes the steps to generate certificates using different tool chains.Kubernetes Container Environment describes the environment for Kubelet managed containers on a Kubernetes node.Controlling Access to the Kubernetes API describes how Kubernetes implements access control for its own API.Authenticating explains authentication in Kubernetes, including the various authentication options.Authorization is separate from authentication, and controls how HTTP calls are handled.Using Admission Controllers explains plug-ins which intercepts requests to the Kubernetes API server after authentication and authorization.Admission Webhook Good Practices provides good practices an


Question: When would you use Cluster Administration?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Cluster AdministrationLower-level detail relevant to creating or administering a Kubernetes cluster.1: Node Shutdowns2: Swap memory management3: Node Autoscaling4: Certificates5: Cluster Networking6: Admission Webhook Good Practices7: Good practices for Dynamic Resource Allocation as a Cluster Admin8: Logging Architecture9: Compatibility Version For Kubernetes Control Plane Components10: Metrics For Kubernetes System Components11: Metrics for Kubernetes Object States12: System Logs13: Traces For Kubernetes System Components14: Proxies in Kubernetes15: API Priority and Fairness16: Installing Addons17: Coordinated Leader ElectionThe cluster administration overview is for anyone creating or administering a Kubernetes cluster. It assumes some familiarity with core Kubernetes concepts.Planning a clusterSee the guides in Setup for examples of how to plan, set up, and configure Kubernetes clusters. The solutions listed in this article are called distros.Note:Not all distros are actively maintained. Choose distros which have been tested with a recent version of Kubernetes.Before choosing a guide, here are some considerations:Do you want to try out Kubernetes on your computer, or do you want to build a high-availability, multi-node cluster? Choose distros best suited for your needs.Will you be using a hosted Kubernetes cluster, such as Google Kubernetes Engine, or hosting your own cluster?Will your cluster be on-premises, or in the cloud (IaaS)? Kubernetes does not directly support hybrid clusters. Instead, you can set up multiple clusters.If you are configuring Kubernetes on-premises, consider which networking model fits best.Will you be running Kubernetes on "bare metal" hardware or on virtual machines (VMs)?Do you want to run a cluster, or do you expect to do active development of Kubernetes project code? If the latter, choose an actively-developed distro. Some distros only use binary releases, but offer a greater variety of choices.Familiarize yourself with the components needed to run a cluster.Managing a clusterLearn how to manage nodes.Read about Node autoscaling.Learn how to set up and manage the resource quota for shared clusters.Securing a clusterGenerate Certificates describes the steps to generate certificates using different tool chains.Kubernetes Container Environment describes the environment for Kubelet managed containers on a Kubernetes node.Controlling Access to the Kubernetes API describes how Kubernetes implements access control for its own API.Authenticating explains authentication in Kubernetes, including the various authentication options.Authorization is separate from authentication, and controls how HTTP calls are handled.Using Admission Controllers explains plug-ins which intercepts requests to the Kubernetes API server after authentication and authorization.Admission Webhook Good Practices provides good practices an


Question: What are the benefits of Cluster Administration?

Answer: This is the multi-page printable view of this section. Click here to print.Return to the regular view of this page.Cluster AdministrationLower-level detail relevant to creating or administering a Kubernetes cluster.1: Node Shutdowns2: Swap memory management3: Node Autoscaling4: Certificates5: Cluster Networking6: Admission Webhook Good Practices7: Good practices for Dynamic Resource Allocation as a Cluster Admin8: Logging Architecture9: Compatibility Version For Kubernetes Control Plane Components10: Metrics For Kubernetes System Components11: Metrics for Kubernetes Object States12: System Logs13: Traces For Kubernetes System Components14: Proxies in Kubernetes15: API Priority and Fairness16: Installing Addons17: Coordinated Leader ElectionThe cluster administration overview is for anyone creating or administering a Kubernetes cluster. It assumes some familiarity with core Kubernetes concepts.Planning a clusterSee the guides in Setup for examples of how to plan, set up, and configure Kubernetes clusters. The solutions listed in this article are called distros.Note:Not all distros are actively maintained. Choose distros which have been tested with a recent version of Kubernetes.Before choosing a guide, here are some considerations:Do you want to try out Kubernetes on your computer, or do you want to build a high-availability, multi-node cluster? Choose distros best suited for your needs.Will you be using a hosted Kubernetes cluster, such as Google Kubernetes Engine, or hosting your own cluster?Will your cluster be on-premises, or in the cloud (IaaS)? Kubernetes does not directly support hybrid clusters. Instead, you can set up multiple clusters.If you are configuring Kubernetes on-premises, consider which networking model fits best.Will you be running Kubernetes on "bare metal" hardware or on virtual machines (VMs)?Do you want to run a cluster, or do you expect to do active development of Kubernetes project code? If the latter, choose an actively-developed distro. Some distros only use binary releases, but offer a greater variety of choices.Familiarize yourself with the components needed to run a cluster.Managing a clusterLearn how to manage nodes.Read about Node autoscaling.Learn how to set up and manage the resource quota for shared clusters.Securing a clusterGenerate Certificates describes the steps to generate certificates using different tool chains.Kubernetes Container Environment describes the environment for Kubelet managed containers on a Kubernetes node.Controlling Access to the Kubernetes API describes how Kubernetes implements access control for its own API.Authenticating explains authentication in Kubernetes, including the various authentication options.Authorization is separate from authentication, and controls how HTTP calls are handled.Using Admission Controllers explains plug-ins which intercepts requests to the Kubernetes API server after authentication and authorization.Admission Webhook Good Practices provides good practices an


Question: What is Cluster Administration?

Answer: 1 :   N o d e   S h u t d o w n s 2 :   S w a p   m e m o r y   m a n a g e m e n t 3 :   N o d e   A u t o s c a l i n g 4 :   C e r t i f i c a t e s 5 :   C l u s t e r   N e t w o r k i n g 6 :   A d m i s s i o n   W e b h o o k   G o o d   P r a c t i c e s 7 :   G o o d   p r a c t i c e s   f o r   D y n a m i c   R e s o u r c e   A l l o c a t i o n   a s   a   C l u s t e r   A d m i n 8 :   L o g g i n g   A r c h i t e c t u r e 9 :   C o m p a t i b i l i t y   V e r s i o n   F o r   K u b e r n e t e s   C o n t r o l   P l a n e   C o m p o n e n t s 1 0 :   M e t r i c s   F o r   K u b e r n e t e s   S y s t e m   C o m p o n e n t s 1 1 :   M e t r i c s   f o r   K u b e r n e t e s   O b j e c t   S t a t e s 1 2 :   S y s t e m   L o g s 1 3 :   T r a c e s   F o r   K u b e r n e t e s   S y s t e m   C o m p o n e n t s 1 4 :   P r o x i e s   i n   K u b e r n e t e s 1 5 :   A P I   P r i o r i t y   a n d   F a i r n e s s 1 6 :   I n s t a l l i n g   A d d o n s 1 7 :   C o o r d i n a t e d   L e a d e r   E l e c t i o n   T h e   c l u s t e r   a d m i n i s t r a t i o n   o v e r v i e w   i s   f o r   a n y o n e   c r e a t i n g   o r   a d m i n i s t e r i n g   a   K u b e r n e t e s   c l u s t e r .   I t   a s s u m e s   s o m e   f a m i l i a r i t y   w i t h   c o r e   K u b e r n e t e s   c o n c e p t s .


Question: What is Planning a cluster?

Answer: S e e   t h e   g u i d e s   i n   S e t u p   f o r   e x a m p l e s   o f   h o w   t o   p l a n ,   s e t   u p ,   a n d   c o n f i g u r e   K u b e r n e t e s   c l u s t e r s .   T h e   s o l u t i o n s   l i s t e d   i n   t h i s   a r t i c l e   a r e   c a l l e d   d i s t r o s .


Question: What is Note:?

Answer: B e f o r e   c h o o s i n g   a   g u i d e ,   h e r e   a r e   s o m e   c o n s i d e r a t i o n s :   D o   y o u   w a n t   t o   t r y   o u t   K u b e r n e t e s   o n   y o u r   c o m p u t e r ,   o r   d o   y o u   w a n t   t o   b u i l d   a   h i g h - a v a i l a b i l i t y ,   m u l t i - n o d e   c l u s t e r ?   C h o o s e   d i s t r o s   b e s t   s u i t e d   f o r   y o u r   n e e d s . W i l l   y o u   b e   u s i n g   a   h o s t e d   K u b e r n e t e s   c l u s t e r ,   s u c h   a s   G o o g l e   K u b e r n e t e s   E n g i n e ,   o r   h o s t i n g   y o u r   o w n   c l u s t e r ? W i l l   y o u r   c l u s t e r   b e   o n - p r e m i s e s ,   o r   i n   t h e   c l o u d   ( I a a S ) ?   K u b e r n e t e s   d o e s   n o t   d i r e c t l y   s u p p o r t   h y b r i d   c l u s t e r s .   I n s t e a d ,   y o u   c a n   s e t   u p   m u l t i p l e   c l u s t e r s . I f   y o u   a r e   c o n f i g u r i n g   K u b e r n e t e s   o n - p r e m i s e s ,   c o n s i d e r   w h i c h   n e t w o r k i n g   m o d e l   f i t s   b e s t . W i l l   y o u   b e   r u n n i n g   K u b e r n e t e s   o n   " b a r e   m e t a l "   h a r d w a r e   o r   o n   v i r t u a l   m a c h i n e s   ( V M s ) ? D o   y o u   w a n t   t o   r u n   a   c l u s t e r ,   o r   d o   y o u   e x p e c t   t o   d o   a c t i v e   d e v e l o p m e n t   o f   K u b e r n e t e s   p r o j e c t   c o d e ?   I f   t h e   l a t t e r ,   c h o o s e   a n   a c t i v e l y - d e v e l o p e d   d i s t r o .   S o m e   d i s t r o s   o n l y   u s e   b i n a r y   r e l e a s e s ,   b u t   o f f e r   a   g r e a t e r   v a r i e t y   o f   c h o i c e s . F a m i l i a r i z e   y o u r s e l f   w i t h   t h e   c o m p o n e n t s   n e e d e d   t o   r u n   a   c l u s t e r .


Question: What is Managing a cluster?

Answer: L e a r n   h o w   t o   m a n a g e   n o d e s . R e a d   a b o u t   N o d e   a u t o s c a l i n g . L e a r n   h o w   t o   s e t   u p   a n d   m a n a g e   t h e   r e s o u r c e   q u o t a   f o r   s h a r e d   c l u s t e r s .   L e a r n   h o w   t o   m a n a g e   n o d e s .   R e a d   a b o u t   N o d e   a u t o s c a l i n g .   L e a r n   h o w   t o   s e t   u p   a n d   m a n a g e   t h e   r e s o u r c e   q u o t a   f o r   s h a r e d   c l u s t e r s .


Question: What is Securing a cluster?

Answer: G e n e r a t e   C e r t i f i c a t e s   d e s c r i b e s   t h e   s t e p s   t o   g e n e r a t e   c e r t i f i c a t e s   u s i n g   d i f f e r e n t   t o o l   c h a i n s . K u b e r n e t e s   C o n t a i n e r   E n v i r o n m e n t   d e s c r i b e s   t h e   e n v i r o n m e n t   f o r   K u b e l e t   m a n a g e d   c o n t a i n e r s   o n   a   K u b e r n e t e s   n o d e . C o n t r o l l i n g   A c c e s s   t o   t h e   K u b e r n e t e s   A P I   d e s c r i b e s   h o w   K u b e r n e t e s   i m p l e m e n t s   a c c e s s   c o n t r o l   f o r   i t s   o w n   A P I . A u t h e n t i c a t i n g   e x p l a i n s   a u t h e n t i c a t i o n   i n   K u b e r n e t e s ,   i n c l u d i n g   t h e   v a r i o u s   a u t h e n t i c a t i o n   o p t i o n s . A u t h o r i z a t i o n   i s   s e p a r a t e   f r o m   a u t h e n t i c a t i o n ,   a n d   c o n t r o l s   h o w   H T T P   c a l l s   a r e   h a n d l e d . U s i n g   A d m i s s i o n   C o n t r o l l e r s   e x p l a i n s   p l u g - i n s   w h i c h   i n t e r c e p t s   r e q u e s t s   t o   t h e   K u b e r n e t e s   A P I   s e r v e r   a f t e r   a u t h e n t i c a t i o n   a n d   a u t h o r i z a t i o n . A d m i s s i o n   W e b h o o k   G o o d   P r a c t i c e s   p r o v i d e s   g o o d   p r a c t i c e s   a n d   c o n s i d e r a t i o n s   w h e n   d e s i g n i n g   m u t a t i n g   a d m i s s i o n   w e b h o o k s   a n d   v a l i d a t i n g   a d m i s s i o n   w e b h o o k s . U s i n g   S y s c t l s   i n   a   K u b e r n e t e s   C l u s t e r   d e s c r i b e s   t o   a n   a d m i n i s t r a t o r   h o w   t o   u s e   t h e   s y s c t l   c o m m a n d - l i n e   t o o l   t o   s e t   k e r n e l   p a r a m e t e r s   . A u d i t i n g   d e s c r i b e s   h o w   t o   i n t e r a c t   w i t h   K u b e r n e t e s '   a u d i t   l o g s .   G e n e r a t e


Question: What is Securing the kubelet?

Answer: C o n t r o l   P l a n e - N o d e   c o m m u n i c a t i o n T L S   b o o t s t r a p p i n g K u b e l e t   a u t h e n t i c a t i o n / a u t h o r i z a t i o n


Question: What is Optional Cluster Services?

Answer: D N S   I n t e g r a t i o n   d e s c r i b e s   h o w   t o   r e s o l v e   a   D N S   n a m e   d i r e c t l y   t o   a   K u b e r n e t e s   s e r v i c e . L o g g i n g   a n d   M o n i t o r i n g   C l u s t e r   A c t i v i t y   e x p l a i n s   h o w   l o g g i n g   i n   K u b e r n e t e s   w o r k s   a n d   h o w   t o   i m p l e m e n t   i t .   D N S   I n t e g r a t i o n   d e s c r i b e s   h o w   t o   r e s o l v e   a   D N S   n a m e   d i r e c t l y   t o   a   K u b e r n e t e s   s e r v i c e .   L o g g i n g   a n d   M o n i t o r i n g   C l u s t e r   A c t i v i t y   e x p l a i n s   h o w   l o g g i n g   i n   K u b e r n e t e s   w o r k s   a n d   h o w   t o   i m p l e m e n t   i t .


Question: What is 1 - Node Shutdowns?

Answer: I n   a   K u b e r n e t e s   c l u s t e r ,   a   n o d e   c a n   b e   s h u t   d o w n   i n   a   p l a n n e d   g r a c e f u l   w a y   o r   u n e x p e c t e d l y   b e c a u s e   o f   r e a s o n s   s u c h   a s   a   p o w e r   o u t a g e   o r   s o m e t h i n g   e l s e   e x t e r n a l .   A   n o d e   s h u t d o w n   c o u l d   l e a d   t o   w o r k l o a d   f a i l u r e   i f   t h e   n o d e   i s   n o t   d r a i n e d   b e f o r e   t h e   s h u t d o w n .   A   n o d e   s h u t d o w n   c a n   b e   e i t h e r   g r a c e f u l   o r   n o n - g r a c e f u l .


Question: What is Graceful node shutdown?

Answer: T h e   k u b e l e t   a t t e m p t s   t o   d e t e c t   n o d e   s y s t e m   s h u t d o w n   a n d   t e r m i n a t e s   p o d s   r u n n i n g   o n   t h e   n o d e .   K u b e l e t   e n s u r e s   t h a t   p o d s   f o l l o w   t h e   n o r m a l   p o d   t e r m i n a t i o n   p r o c e s s   d u r i n g   t h e   n o d e   s h u t d o w n .   D u r i n g   n o d e   s h u t d o w n ,   t h e   k u b e l e t   d o e s   n o t   a c c e p t   n e w   P o d s   ( e v e n   i f   t h o s e   P o d s   a r e   a l r e a d y   b o u n d   t o   t h e   n o d e ) .


Question: What is Enabling graceful node shutdown?

Answer: F E A T U R E   S T A T E :   K u b e r n e t e s   v 1 . 2 1   [ b e t a ]   ( e n a b l e d   b y   d e f a u l t :   t r u e ) O n   L i n u x ,   t h e   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   i s   c o n t r o l l e d   w i t h   t h e   G r a c e f u l N o d e S h u t d o w n   f e a t u r e   g a t e   w h i c h   i s   e n a b l e d   b y   d e f a u l t   i n   1 . 2 1 . N o t e : T h e   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   d e p e n d s   o n   s y s t e m d   s i n c e   i t   t a k e s   a d v a n t a g e   o f   s y s t e m d   i n h i b i t o r   l o c k s   t o   d e l a y   t h e   n o d e   s h u t d o w n   w i t h   a   g i v e n   d u r a t i o n .   O n   L i n u x ,   t h e   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   i s   c o n t r o l l e d   w i t h   t h e   G r a c e f u l N o d e S h u t d o w n   f e a t u r e   g a t e   w h i c h   i s   e n a b l e d   b y   d e f a u l t   i n   1 . 2 1 .


Question: What is Note:?

Answer: F E A T U R E   S T A T E :   K u b e r n e t e s   v 1 . 3 4   [ b e t a ]   ( e n a b l e d   b y   d e f a u l t :   t r u e ) O n   W i n d o w s ,   t h e   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   i s   c o n t r o l l e d   w i t h   t h e   W i n d o w s G r a c e f u l N o d e S h u t d o w n   f e a t u r e   g a t e   w h i c h   i s   i n t r o d u c e d   i n   1 . 3 2   a s   a n   a l p h a   f e a t u r e .   I n   K u b e r n e t e s   1 . 3 4   t h e   f e a t u r e   i s   B e t a   a n d   i s   e n a b l e d   b y   d e f a u l t . N o t e : T h e   W i n d o w s   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   d e p e n d s   o n   k u b e l e t   r u n n i n g   a s   a   W i n d o w s   s e r v i c e ,   i t   w i l l   t h e n   h a v e   a   r e g i s t e r e d   s e r v i c e   c o n t r o l   h a n d l e r   t o   d e l a y   t h e   p r e s h u t d o w n   e v e n t   w i t h   a   g i v e n   d u r a t i o n . W i n d o w s   g r a c e f u l   n o d e   s h u t d o w n   c a n   n o t   b e   c a n c e l l e d . I f   k u b e l e t   i s   n o t   r u n n i n g   a s   a   W i n d o w s   s e r v i c e ,   i t   w i l l   n o t   b e   a b l e   t o   s e t   a n d   m o n i t o r   t h e   P r e s h u t d o w n   e v e n t ,   t h e   n o d e   w i l l   h a v e   t o   g o   t h r o u g h   t h e   N o n - G r a c e f u l   N o d e   S h u t d o w n   p r o c e d u r e   m e n t i o n e d   a b o v e . I n   t h e   c a s e   w h e r e   t h e   W i n d o w s   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   i s   e n a b l e d ,   b u t   t h e   k u b e l e t   i s   n o t   r u n n i n g   a s   a   W i n d o w s   s e r v i c e ,   t h e   k u b e l e t   w i l l   c o n t i n u e   r u n n i n g   i n s t e a d   o f   f a i l i n g .   H o w e v e r ,   i t   w i l l   l o g   a n   e r r o r   i n d i c a t i n g   t h a t   i t   n e e d s   t o   b e   r u n   a s   a   W i n


Question: What is Note:?

Answer: W i n d o w s   g r a c e f u l   n o d e   s h u t d o w n   c a n   n o t   b e   c a n c e l l e d .   I f   k u b e l e t   i s   n o t   r u n n i n g   a s   a   W i n d o w s   s e r v i c e ,   i t   w i l l   n o t   b e   a b l e   t o   s e t   a n d   m o n i t o r   t h e   P r e s h u t d o w n   e v e n t ,   t h e   n o d e   w i l l   h a v e   t o   g o   t h r o u g h   t h e   N o n - G r a c e f u l   N o d e   S h u t d o w n   p r o c e d u r e   m e n t i o n e d   a b o v e .   I n   t h e   c a s e   w h e r e   t h e   W i n d o w s   g r a c e f u l   n o d e   s h u t d o w n   f e a t u r e   i s   e n a b l e d ,   b u t   t h e   k u b e l e t   i s   n o t   r u n n i n g   a s   a   W i n d o w s   s e r v i c e ,   t h e   k u b e l e t   w i l l   c o n t i n u e   r u n n i n g   i n s t e a d   o f   f a i l i n g .   H o w e v e r ,   i t   w i l l   l o g   a n   e r r o r   i n d i c a t i n g   t h a t   i t   n e e d s   t o   b e   r u n   a s   a   W i n d o w s   s e r v i c e .


Question: What is Configuring graceful node shutdown?

Answer: N o t e   t h a t   b y   d e f a u l t ,   b o t h   c o n f i g u r a t i o n   o p t i o n s   d e s c r i b e d   b e l o w ,   s h u t d o w n G r a c e P e r i o d   a n d   s h u t d o w n G r a c e P e r i o d C r i t i c a l P o d s ,   a r e   s e t   t o   z e r o ,   t h u s   n o t   a c t i v a t i n g   t h e   g r a c e f u l   n o d e   s h u t d o w n   f u n c t i o n a l i t y .   T o   a c t i v a t e   t h e   f e a t u r e ,   b o t h   o p t i o n s   s h o u l d   b e   c o n f i g u r e d   a p p r o p r i a t e l y   a n d   s e t   t o   n o n - z e r o   v a l u e s .   O n c e   t h e   k u b e l e t   i s   n o t i f i e d   o f   a   n o d e   s h u t d o w n ,   i t   s e t s   a   N o t R e a d y   c o n d i t i o n   o n   t h e   N o d e ,   w i t h   t h e   r e a s o n   s e t   t o   " n o d e   i s   s h u t t i n g   d o w n " .   T h e   k u b e - s c h e d u l e r   h o n o r s   t h i s   c o n d i t i o n   a n d   d o e s   n o t   s c h e d u l e   a n y   P o d s   o n t o   t h e   a f f e c t e d   n o d e ;   o t h e r   t h i r d - p a r t y   s c h e d u l e r s   a r e   e x p e c t e d   t o   f o l l o w   t h e   s a m e   l o g i c .   T h i s   m e a n s   t h a t   n e w   P o d s   w o n ' t   b e   s c h e d u l e d   o n t o   t h a t   n o d e   a n d   t h e r e f o r e   n o n e   w i l l   s t a r t .   T h e   k u b e l e t   a l s o   r e j e c t s   P o d s   d u r i n g   t h e   P o d A d m i s s i o n   p h a s e   i f   a n   o n g o i n g   n o d e   s h u t d o w n   h a s   b e e n   d e t e c t e d ,   s o   t h a t   e v e n   P o d s   w i t h   a   t o l e r a t i o n   f o r   n o d e . k u b e r n e t e s . i o / n o t - r e a d y : N o S c h e d u l e   d o   n o t   s t a r t   t h e r e .   W h e n   k u b e l e t   i s   s e t t i n g   t h a t   c o n d i t i o n   o n   i t s   N o d e   v i a   t h e   A P I ,   t h e   k u b e l e t   a l s o   b e g i n s   t e r m i n a t i


Question: What is Note:?

Answer: F o r   e x a m p l e ,   i f   s h u t d o w n G r a c e P e r i o d = 3 0 s ,   a n d   s h u t d o w n G r a c e P e r i o d C r i t i c a l P o d s = 1 0 s ,   k u b e l e t   w i l l   d e l a y   t h e   n o d e   s h u t d o w n   b y   3 0   s e c o n d s .   D u r i n g   t h e   s h u t d o w n ,   t h e   f i r s t   2 0   ( 3 0 - 1 0 )   s e c o n d s   w o u l d   b e   r e s e r v e d   f o r   g r a c e f u l l y   t e r m i n a t i n g   n o r m a l   p o d s ,   a n d   t h e   l a s t   1 0   s e c o n d s   w o u l d   b e   r e s e r v e d   f o r   t e r m i n a t i n g   c r i t i c a l   p o d s .


Question: What is Note:?

Answer: W h e n   p o d s   w e r e   e v i c t e d   d u r i n g   t h e   g r a c e f u l   n o d e   s h u t d o w n ,   t h e y   a r e   m a r k e d   a s   s h u t d o w n .   R u n n i n g   k u b e c t l   g e t   p o d s   s h o w s   t h e   s t a t u s   o f   t h e   e v i c t e d   p o d s   a s   T e r m i n a t e d .   A n d   k u b e c t l   d e s c r i b e   p o d   i n d i c a t e s   t h a t   t h e   p o d   w a s   e v i c t e d   b e c a u s e   o f   n o d e   s h u t d o w n :   R e a s o n :   T e r m i n a t e d   M e s s a g e :   P o d   w a s   t e r m i n a t e d   i n   r e s p o n s e   t o   i m m i n e n t   n o d e   s h u t d o w n .


Question: What is Pod Priority based graceful node shutdown?

Answer: T o   p r o v i d e   m o r e   f l e x i b i l i t y   d u r i n g   g r a c e f u l   n o d e   s h u t d o w n   a r o u n d   t h e   o r d e r i n g   o f   p o d s   d u r i n g   s h u t d o w n ,   g r a c e f u l   n o d e   s h u t d o w n   h o n o r s   t h e   P r i o r i t y C l a s s   f o r   P o d s ,   p r o v i d e d   t h a t   y o u   e n a b l e d   t h i s   f e a t u r e   i n   y o u r   c l u s t e r .   T h e   f e a t u r e   a l l o w s   c l u s t e r   a d m i n i s t r a t o r s   t o   e x p l i c i t l y   d e f i n e   t h e   o r d e r i n g   o f   p o d s   d u r i n g   g r a c e f u l   n o d e   s h u t d o w n   b a s e d   o n   p r i o r i t y   c l a s s e s .   T h e   G r a c e f u l   N o d e   S h u t d o w n   f e a t u r e ,   a s   d e s c r i b e d   a b o v e ,   s h u t s   d o w n   p o d s   i n   t w o   p h a s e s ,   n o n - c r i t i c a l   p o d s ,   f o l l o w e d   b y   c r i t i c a l   p o d s .   I f   a d d i t i o n a l   f l e x i b i l i t y   i s   n e e d e d   t o   e x p l i c i t l y   d e f i n e   t h e   o r d e r i n g   o f   p o d s   d u r i n g   s h u t d o w n   i n   a   m o r e   g r a n u l a r   w a y ,   p o d   p r i o r i t y   b a s e d   g r a c e f u l   s h u t d o w n   c a n   b e   u s e d .   W h e n   g r a c e f u l   n o d e   s h u t d o w n   h o n o r s   p o d   p r i o r i t i e s ,   t h i s   m a k e s   i t   p o s s i b l e   t o   d o   g r a c e f u l   n o d e   s h u t d o w n   i n   m u l t i p l e   p h a s e s ,   e a c h   p h a s e   s h u t t i n g   d o w n   a   p a r t i c u l a r   p r i o r i t y   c l a s s   o f   p o d s .   T h e   k u b e l e t   c a n   b e   c o n f i g u r e d   w i t h   t h e   e x a c t   p h a s e s   a n d   s h u t d o w n   t i m e   p e r   p h a s e .   A s s u m i n g   t h e   f o l l o w i n g   c u s t o m   p o d   p r i o r i t y   c l a s s e s   i n   a   c l u s t e r ,   W i t h i n   t h e


Question: What is Note:?

Answer: M e t r i c s   g r a c e f u l _ s h u t d o w n _ s t a r t _ t i m e _ s e c o n d s   a n d   g r a c e f u l _ s h u t d o w n _ e n d _ t i m e _ s e c o n d s   a r e   e m i t t e d   u n d e r   t h e   k u b e l e t   s u b s y s t e m   t o   m o n i t o r   n o d e   s h u t d o w n s .


Question: What is Non-graceful node shutdown handling?

Answer: A   n o d e   s h u t d o w n   a c t i o n   m a y   n o t   b e   d e t e c t e d   b y   k u b e l e t ' s   N o d e   S h u t d o w n   M a n a g e r ,   e i t h e r   b e c a u s e   t h e   c o m m a n d   d o e s   n o t   t r i g g e r   t h e   i n h i b i t o r   l o c k s   m e c h a n i s m   u s e d   b y   k u b e l e t   o r   b e c a u s e   o f   a   u s e r   e r r o r ,   i . e . ,   t h e   S h u t d o w n G r a c e P e r i o d   a n d   S h u t d o w n G r a c e P e r i o d C r i t i c a l P o d s   a r e   n o t   c o n f i g u r e d   p r o p e r l y .   P l e a s e   r e f e r   t o   a b o v e   s e c t i o n   G r a c e f u l   N o d e   S h u t d o w n   f o r   m o r e   d e t a i l s .   W h e n   a   n o d e   i s   s h u t d o w n   b u t   n o t   d e t e c t e d   b y   k u b e l e t ' s   N o d e   S h u t d o w n   M a n a g e r ,   t h e   p o d s   t h a t   a r e   p a r t   o f   a   S t a t e f u l S e t   w i l l   b e   s t u c k   i n   t e r m i n a t i n g   s t a t u s   o n   t h e   s h u t d o w n   n o d e   a n d   c a n n o t   m o v e   t o   a   n e w   r u n n i n g   n o d e .   T h i s   i s   b e c a u s e   k u b e l e t   o n   t h e   s h u t d o w n   n o d e   i s   n o t   a v a i l a b l e   t o   d e l e t e   t h e   p o d s   s o   t h e   S t a t e f u l S e t   c a n n o t   c r e a t e   a   n e w   p o d   w i t h   t h e   s a m e   n a m e .   I f   t h e r e   a r e   v o l u m e s   u s e d   b y   t h e   p o d s ,   t h e   V o l u m e A t t a c h m e n t s   w i l l   n o t   b e   d e l e t e d   f r o m   t h e   o r i g i n a l   s h u t d o w n   n o d e   s o   t h e   v o l u m e s   u s e d   b y   t h e s e   p o d s   c a n n o t   b e   a t t a c h e d   t o   a   n e w   r u n n i n g   n o d e .   A s   a   r e s u l t ,   t h e   a p p l i c a t i o n   r u n n i n g   o n   t h e   S t a t e f u l S e t   c a n n o t   f u n c t i o n   p r o p e r l y .   I f   t h e   o r


Question: What is Note:?

Answer: B e f o r e   a d d i n g   t h e   t a i n t   n o d e . k u b e r n e t e s . i o / o u t - o f - s e r v i c e ,   i t   s h o u l d   b e   v e r i f i e d   t h a t   t h e   n o d e   i s   a l r e a d y   i n   s h u t d o w n   o r   p o w e r   o f f   s t a t e   ( n o t   i n   t h e   m i d d l e   o f   r e s t a r t i n g ) . T h e   u s e r   i s   r e q u i r e d   t o   m a n u a l l y   r e m o v e   t h e   o u t - o f - s e r v i c e   t a i n t   a f t e r   t h e   p o d s   a r e   m o v e d   t o   a   n e w   n o d e   a n d   t h e   u s e r   h a s   c h e c k e d   t h a t   t h e   s h u t d o w n   n o d e   h a s   b e e n   r e c o v e r e d   s i n c e   t h e   u s e r   w a s   t h e   o n e   w h o   o r i g i n a l l y   a d d e d   t h e   t a i n t .


Question: What is Forced storage detach on timeout?

Answer: I n   a n y   s i t u a t i o n   w h e r e   a   p o d   d e l e t i o n   h a s   n o t   s u c c e e d e d   f o r   6   m i n u t e s ,   k u b e r n e t e s   w i l l   f o r c e   d e t a c h   v o l u m e s   b e i n g   u n m o u n t e d   i f   t h e   n o d e   i s   u n h e a l t h y   a t   t h a t   i n s t a n t .   A n y   w o r k l o a d   s t i l l   r u n n i n g   o n   t h e   n o d e   t h a t   u s e s   a   f o r c e - d e t a c h e d   v o l u m e   w i l l   c a u s e   a   v i o l a t i o n   o f   t h e   C S I   s p e c i f i c a t i o n ,   w h i c h   s t a t e s   t h a t   C o n t r o l l e r U n p u b l i s h V o l u m e   " m u s t   b e   c a l l e d   a f t e r   a l l   N o d e U n s t a g e V o l u m e   a n d   N o d e U n p u b l i s h V o l u m e   o n   t h e   v o l u m e   a r e   c a l l e d   a n d   s u c c e e d " .   I n   s u c h   c i r c u m s t a n c e s ,   v o l u m e s   o n   t h e   n o d e   i n   q u e s t i o n   m i g h t   e n c o u n t e r   d a t a   c o r r u p t i o n .   T h e   f o r c e d   s t o r a g e   d e t a c h   b e h a v i o u r   i s   o p t i o n a l ;   u s e r s   m i g h t   o p t   t o   u s e   t h e   " N o n - g r a c e f u l   n o d e   s h u t d o w n "   f e a t u r e   i n s t e a d .   F o r c e   s t o r a g e   d e t a c h   o n   t i m e o u t   c a n   b e   d i s a b l e d   b y   s e t t i n g   t h e   d i s a b l e - f o r c e - d e t a c h - o n - t i m e o u t   c o n f i g   f i e l d   i n   k u b e - c o n t r o l l e r - m a n a g e r .   D i s a b l i n g   t h e   f o r c e   d e t a c h   o n   t i m e o u t   f e a t u r e   m e a n s   t h a t   a   v o l u m e   t h a t   i s   h o s t e d   o n   a   n o d e   t h a t   i s   u n h e a l t h y   f o r   m o r e   t h a n   6   m i n u t e s   w i l l   n o t   h a v e   i t s   a s s o c i a t e d   V o l u m e A t t a c h m e n t   d e l e t e d .   A f t e r   t h i s   s e t t i n g   h a s   b e e n


Question: What is Note:?

Answer: C a u t i o n   m u s t   b e   t a k e n   w h i l e   u s i n g   t h e   N o n - G r a c e f u l   N o d e   S h u t d o w n   p r o c e d u r e . D e v i a t i o n   f r o m   t h e   s t e p s   d o c u m e n t e d   a b o v e   c a n   r e s u l t   i n   d a t a   c o r r u p t i o n .


Question: What is What's next?

Answer: L e a r n   m o r e   a b o u t   t h e   f o l l o w i n g :   B l o g :   N o n - G r a c e f u l   N o d e   S h u t d o w n . C l u s t e r   A r c h i t e c t u r e :   N o d e s .


Question: What is 2 - Swap memory management?

Answer: K u b e r n e t e s   c a n   b e   c o n f i g u r e d   t o   u s e   s w a p   m e m o r y   o n   a   n o d e ,   a l l o w i n g   t h e   k e r n e l   t o   f r e e   u p   p h y s i c a l   m e m o r y   b y   s w a p p i n g   o u t   p a g e s   t o   b a c k i n g   s t o r a g e .   T h i s   i s   u s e f u l   f o r   m u l t i p l e   u s e - c a s e s .   F o r   e x a m p l e ,   n o d e s   r u n n i n g   w o r k l o a d s   t h a t   c a n   b e n e f i t   f r o m   u s i n g   s w a p ,   s u c h   a s   t h o s e   t h a t   h a v e   l a r g e   m e m o r y   f o o t p r i n t s   b u t   o n l y   a c c e s s   a   p o r t i o n   o f   t h a t   m e m o r y   a t   a n y   g i v e n   t i m e .   I t   a l s o   h e l p s   p r e v e n t   P o d s   f r o m   b e i n g   t e r m i n a t e d   d u r i n g   m e m o r y   p r e s s u r e   s p i k e s ,   s h i e l d s   n o d e s   f r o m   s y s t e m - l e v e l   m e m o r y   s p i k e s   t h a t   m i g h t   c o m p r o m i s e   i t s   s t a b i l i t y ,   a l l o w s   f o r   m o r e   f l e x i b l e   m e m o r y   m a n a g e m e n t   o n   t h e   n o d e ,   a n d   m u c h   m o r e .   T o   l e a r n   a b o u t   c o n f i g u r i n g   s w a p   i n   y o u r   c l u s t e r ,   r e a d   C o n f i g u r i n g   s w a p   m e m o r y   o n   K u b e r n e t e s   n o d e s .


Question: What is Operating system support?

Answer: L i n u x   n o d e s   s u p p o r t   s w a p ;   y o u   n e e d   t o   c o n f i g u r e   e a c h   n o d e   t o   e n a b l e   i t .   B y   d e f a u l t ,   t h e   k u b e l e t   w i l l   n o t   s t a r t   o n   a   L i n u x   n o d e   t h a t   h a s   s w a p   e n a b l e d . W i n d o w s   n o d e s   r e q u i r e   s w a p   s p a c e .   B y   d e f a u l t ,   t h e   k u b e l e t   d o e s   n o t   s t a r t   o n   a   W i n d o w s   n o d e   t h a t   h a s   s w a p   d i s a b l e d .


Question: What is How does it work??

Answer: T h e r e   a r e   a   n u m b e r   o f   p o s s i b l e   w a y s   t h a t   o n e   c o u l d   e n v i s i o n   s w a p   u s e   o n   a   n o d e .   I f   k u b e l e t   i s   a l r e a d y   r u n n i n g   o n   a   n o d e ,   i t   w o u l d   n e e d   t o   b e   r e s t a r t e d   a f t e r   s w a p   i s   p r o v i s i o n e d   i n   o r d e r   t o   i d e n t i f y   i t .   W h e n   k u b e l e t   s t a r t s   o n   a   n o d e   i n   w h i c h   s w a p   i s   p r o v i s i o n e d   a n d   a v a i l a b l e   ( w i t h   t h e   f a i l S w a p O n :   f a l s e   c o n f i g u r a t i o n ) ,   k u b e l e t   w i l l :   B e   a b l e   t o   s t a r t   o n   t h i s   s w a p - e n a b l e d   n o d e . D i r e c t   t h e   C o n t a i n e r   R u n t i m e   I n t e r f a c e   ( C R I )   i m p l e m e n t a t i o n ,   o f t e n   r e f e r r e d   t o   a s   t h e   c o n t a i n e r   r u n t i m e ,   t o   a l l o c a t e   z e r o   s w a p   m e m o r y   t o   K u b e r n e t e s   w o r k l o a d s   b y   d e f a u l t .   S w a p   c o n f i g u r a t i o n   o n   a   n o d e   i s   e x p o s e d   t o   a   c l u s t e r   a d m i n   v i a   t h e   m e m o r y S w a p   i n   t h e   K u b e l e t C o n f i g u r a t i o n .   A s   a   c l u s t e r   a d m i n i s t r a t o r ,   y o u   c a n   s p e c i f y   t h e   n o d e ' s   b e h a v i o u r   i n   t h e   p r e s e n c e   o f   s w a p   m e m o r y   b y   s e t t i n g   m e m o r y S w a p . s w a p B e h a v i o r .


Question: What is Swap behaviors?

Answer: Y o u   n e e d   t o   p i c k   a   s w a p   b e h a v i o r   t o   u s e .   D i f f e r e n t   n o d e s   i n   y o u r   c l u s t e r   c a n   u s e   d i f f e r e n t   s w a p   b e h a v i o r s .   T h e   s w a p   b e h a v i o r s   y o u   c a n   c h o o s e   f o r   L i n u x   n o d e s   a r e :


Question: What is Note:?

Answer: I f   y o u   c h o o s e   t h e   N o S w a p   b e h a v i o r ,   a n d   y o u   c o n f i g u r e   t h e   k u b e l e t   t o   t o l e r a t e   s w a p   s p a c e   ( f a i l S w a p O n :   f a l s e ) ,   t h e n   y o u r   w o r k l o a d s   d o n ' t   u s e   a n y   s w a p .   H o w e v e r ,   p r o c e s s e s   o u t s i d e   o f   K u b e r n e t e s - m a n a g e d   c o n t a i n e r s ,   s u c h   a s   s y s t e m i   s e r v i c e s   ( a n d   e v e n   t h e   k u b e l e t   i t s e l f ! )   c a n   u t i l i z e   s w a p .   Y o u   c a n   r e a d   c o n f i g u r i n g   s w a p   m e m o r y   o n   K u b e r n e t e s   n o d e s   t o   l e a r n   a b o u t   e n a b l i n g   s w a p   f o r   y o u r   c l u s t e r .


Question: What is Container runtime integration?

Answer: T h e   k u b e l e t   u s e s   t h e   c o n t a i n e r   r u n t i m e   A P I ,   a n d   d i r e c t s   t h e   c o n t a i n e r   r u n t i m e   t o   a p p l y   s p e c i f i c   c o n f i g u r a t i o n   ( f o r   e x a m p l e ,   i n   t h e   c g r o u p   v 2   c a s e ,   m e m o r y . s w a p . m a x )   i n   a   m a n n e r   t h a t   w i l l   e n a b l e   t h e   d e s i r e d   s w a p   c o n f i g u r a t i o n   f o r   a   c o n t a i n e r .   F o r   r u n t i m e s   t h a t   u s e   c o n t r o l   g r o u p s ,   o r   c g r o u p s ,   t h e   c o n t a i n e r   r u n t i m e   i s   t h e n   r e s p o n s i b l e   f o r   w r i t i n g   t h e s e   s e t t i n g s   t o   t h e   c o n t a i n e r - l e v e l   c g r o u p .


Question: What is Node and container level metric statistics?

Answer: K u b e l e t   n o w   c o l l e c t s   n o d e   a n d   c o n t a i n e r   l e v e l   m e t r i c   s t a t i s t i c s ,   w h i c h   c a n   b e   a c c e s s e d   a t   t h e   / m e t r i c s / r e s o u r c e   ( w h i c h   i s   u s e d   m a i n l y   b y   m o n i t o r i n g   t o o l s   l i k e   P r o m e t h e u s )   a n d   / s t a t s / s u m m a r y   ( w h i c h   i s   u s e d   m a i n l y   b y   A u t o s c a l e r s )   k u b e l e t   H T T P   e n d p o i n t s .   T h i s   a l l o w s   c l i e n t s   w h o   c a n   d i r e c t l y   r e q u e s t   t h e   k u b e l e t   t o   m o n i t o r   s w a p   u s a g e   a n d   r e m a i n i n g   s w a p   m e m o r y   w h e n   u s i n g   L i m i t e d S w a p .   A d d i t i o n a l l y ,   a   m a c h i n e _ s w a p _ b y t e s   m e t r i c   h a s   b e e n   a d d e d   t o   c a d v i s o r   t o   s h o w   t h e   t o t a l   p h y s i c a l   s w a p   c a p a c i t y   o f   t h e   m a c h i n e .   S e e   t h i s   p a g e   f o r   m o r e   i n f o .   F o r   e x a m p l e ,   t h e s e   / m e t r i c s / r e s o u r c e   a r e   s u p p o r t e d :   n o d e _ s w a p _ u s a g e _ b y t e s :   C u r r e n t   s w a p   u s a g e   o f   t h e   n o d e   i n   b y t e s . c o n t a i n e r _ s w a p _ u s a g e _ b y t e s :   C u r r e n t   a m o u n t   o f   t h e   c o n t a i n e r   s w a p   u s a g e   i n   b y t e s . c o n t a i n e r _ s w a p _ l i m i t _ b y t e s :   C u r r e n t   a m o u n t   o f   t h e   c o n t a i n e r   s w a p   l i m i t   i n   b y t e s .


Question: What is Using kubectl top --show-swap?

Answer: Q u e r y i n g   m e t r i c s   i s   v a l u a b l e ,   b u t   s o m e w h a t   c u m b e r s o m e ,   a s   t h e s e   m e t r i c s   a r e   d e s i g n e d   t o   b e   u s e d   b y   s o f t w a r e   r a t h e r   t h a n   h u m a n s .   I n   o r d e r   t o   c o n s u m e   t h i s   d a t a   i n   a   m o r e   u s e r - f r i e n d l y   w a y ,   t h e   k u b e c t l   t o p   c o m m a n d   h a s   b e e n   e x t e n d e d   t o   s u p p o r t   s w a p   m e t r i c s ,   u s i n g   t h e   - - s h o w - s w a p   f l a g .   I n   o r d e r   t o   r e c e i v e   i n f o r m a t i o n   a b o u t   s w a p   u s a g e   o n   n o d e s ,   k u b e c t l   t o p   n o d e s   - - s h o w - s w a p   c a n   b e   u s e d :   k u b e c t l   t o p   n o d e s   - - s h o w - s w a p   T h i s   w i l l   r e s u l t   i n   a n   o u t p u t   s i m i l a r   t o :   N A M E   C P U ( c o r e s )   C P U ( % )   M E M O R Y ( b y t e s )   M E M O R Y ( % )   S W A P ( b y t e s )   S W A P ( % )   n o d e 1   1 m   1 0 %   2 M i   1 0 %   1 M i   0 %   n o d e 2   5 m   1 0 %   6 M i   1 0 %   2 M i   0 %   n o d e 3   3 m   1 0 %   4 M i   1 0 %   < u n k n o w n >   < u n k n o w n >   I n   o r d e r   t o   r e c e i v e   i n f o r m a t i o n   a b o u t   s w a p   u s a g e   b y   p o d s ,   k u b e c t l   t o p   n o d e s   - - s h o w - s w a p   c a n   b e   u s e d :   k u b e c t l   t o p   p o d   - n   k u b e - s y s t e m   - - s h o w - s w a p   T h i s   w i l l   r e s u l t   i n   a n   o u t p u t   s i m i l a r   t o :   N A M E   C P U ( c o r e s )   M E M O R Y ( b y t e s )   S W A P ( b y t e s )   c o r e d n s - 5 8 d 5 b c 5 c d b - 5 n b k 4   2 m   1 9 M i   0 M i   c o r e d n s - 5 8 d 5 b c 5 c d b - j s h 2 6   3 m   3 7 M i   0 M i   e t c d - n o d e 0 1   5 1 m   1 4 3 M i   5 M i   k u b e - a p i s e r v e r - n o d e 0 1   9 8 m   8 2 4 M i   1 6 M i   k u b e - c o n t r o l l e r


Question: What is Nodes to report swap capacity as part of node status?

Answer: A   n e w   n o d e   s t a t u s   f i e l d   i s   n o w   a d d e d ,   n o d e . s t a t u s . n o d e I n f o . s w a p . c a p a c i t y ,   t o   r e p o r t   t h e   s w a p   c a p a c i t y   o f   a   n o d e .   A s   a n   e x a m p l e ,   t h e   f o l l o w i n g   c o m m a n d   c a n   b e   u s e d   t o   r e t r i e v e   t h e   s w a p   c a p a c i t y   o f   t h e   n o d e s   i n   a   c l u s t e r :   k u b e c t l   g e t   n o d e s   - o   g o - t e m p l a t e = ' { { r a n g e   . i t e m s } } { { . m e t a d a t a . n a m e } } :   { { i f   . s t a t u s . n o d e I n f o . s w a p . c a p a c i t y } } { { . s t a t u s . n o d e I n f o . s w a p . c a p a c i t y } } { { e l s e } } < u n k n o w n > { { e n d } } { { " \ n " } } { { e n d } } '   T h i s   w i l l   r e s u l t   i n   a n   o u t p u t   s i m i l a r   t o :   n o d e 1 :   2 1 4 7 4 8 3 6 4 8 0   n o d e 2 :   4 2 9 4 9 6 6 4 7 6 8   n o d e 3 :   < u n k n o w n >


Question: What is Swap discovery using Node Feature Discovery (NFD)?

Answer: N o d e   F e a t u r e   D i s c o v e r y   i s   a   K u b e r n e t e s   a d d o n   f o r   d e t e c t i n g   h a r d w a r e   f e a t u r e s   a n d   c o n f i g u r a t i o n .   I t   c a n   b e   u t i l i z e d   t o   d i s c o v e r   w h i c h   n o d e s   a r e   p r o v i s i o n e d   w i t h   s w a p .   A s   a n   e x a m p l e ,   t o   f i g u r e   o u t   w h i c h   n o d e s   a r e   p r o v i s i o n e d   w i t h   s w a p ,   u s e   t h e   f o l l o w i n g   c o m m a n d :   k u b e c t l   g e t   n o d e s   - o   j s o n p a t h = ' { r a n g e   . i t e m s [ ? ( @ . m e t a d a t a . l a b e l s . f e a t u r e \ . n o d e \ . k u b e r n e t e s \ . i o / m e m o r y - s w a p ) ] } { . m e t a d a t a . n a m e } { " \ t " } { . m e t a d a t a . l a b e l s . f e a t u r e \ . n o d e \ . k u b e r n e t e s \ . i o / m e m o r y - s w a p } { " \ n " } { e n d } '   T h i s   w i l l   r e s u l t   i n   a n   o u t p u t   s i m i l a r   t o :   k 8 s - w o r k e r 1 :   t r u e   k 8 s - w o r k e r 2 :   t r u e   k 8 s - w o r k e r 3 :   f a l s e   I n   t h i s   e x a m p l e ,   s w a p   i s   p r o v i s i o n e d   o n   n o d e s   k 8 s - w o r k e r 1   a n d   k 8 s - w o r k e r 2 ,   b u t   n o t   o n   k 8 s - w o r k e r 3 .