Question: When would you use kubectl?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information in Command line tool (kubectl).kubectl [flags] Options--add-dir-headerIf true, adds the file directory to the header of the log messages--alsologtostderrlog to standard error as well as files--as stringUsername to impersonate for the operation--as-group stringArrayGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--azure-container-registry-config stringPath to the file containing Azure container registry configuration information.--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--cloud-provider-gce-l7lb-src-cidrs cidrs Default: 130.211.0.0/22,35.191.0.0/16CIDRs opened in GCE firewall for L7 LB traffic proxy & health checks--cloud-provider-gce-lb-src-cidrs cidrs Default: 130.211.0.0/22,209.85.152.0/22,209.85.204.0/22,35.191.0.0/16CIDRs opened in GCE firewall for L4 LB traffic proxy & health checks--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--default-not-ready-toleration-seconds int Default: 300Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.--default-unreachable-toleration-seconds int Default: 300Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.-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.--log-backtrace-at traceLocation Default: :0when logging hits line file:N, emit a stack trace--log-dir stringIf non-empty, write log files in this directory--log-file stringIf non-empty, use this log file--log-file-max-size uint Default: 1800Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited.--log-flush-frequency duration Default: 5sMaximum number of seconds between log flushes--logtostderr Default: truelog to standard error instead of files--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--one-outputIf true, only write logs to their native severity level (vs also writing to each lower severity level)--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 stri


Question: What are the benefits of kubectl?

Answer: kubectlSynopsiskubectl controls the Kubernetes cluster manager.Find more information in Command line tool (kubectl).kubectl [flags] Options--add-dir-headerIf true, adds the file directory to the header of the log messages--alsologtostderrlog to standard error as well as files--as stringUsername to impersonate for the operation--as-group stringArrayGroup to impersonate for the operation, this flag can be repeated to specify multiple groups.--azure-container-registry-config stringPath to the file containing Azure container registry configuration information.--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--cloud-provider-gce-l7lb-src-cidrs cidrs Default: 130.211.0.0/22,35.191.0.0/16CIDRs opened in GCE firewall for L7 LB traffic proxy & health checks--cloud-provider-gce-lb-src-cidrs cidrs Default: 130.211.0.0/22,209.85.152.0/22,209.85.204.0/22,35.191.0.0/16CIDRs opened in GCE firewall for L4 LB traffic proxy & health checks--cluster stringThe name of the kubeconfig cluster to use--context stringThe name of the kubeconfig context to use--default-not-ready-toleration-seconds int Default: 300Indicates the tolerationSeconds of the toleration for notReady:NoExecute that is added by default to every pod that does not already have such a toleration.--default-unreachable-toleration-seconds int Default: 300Indicates the tolerationSeconds of the toleration for unreachable:NoExecute that is added by default to every pod that does not already have such a toleration.-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.--log-backtrace-at traceLocation Default: :0when logging hits line file:N, emit a stack trace--log-dir stringIf non-empty, write log files in this directory--log-file stringIf non-empty, use this log file--log-file-max-size uint Default: 1800Defines the maximum size a log file can grow to. Unit is megabytes. If the value is 0, the maximum file size is unlimited.--log-flush-frequency duration Default: 5sMaximum number of seconds between log flushes--logtostderr Default: truelog to standard error instead of files--match-server-versionRequire server version to match client version-n, --namespace stringIf present, the namespace scope for this CLI request--one-outputIf true, only write logs to their native severity level (vs also writing to each lower severity level)--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 stri


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   i n   C o m m a n d   l i n e   t o o l   ( k u b e c t l ) .   k u b e c t l   [ f l a g s ]


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 ,   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 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   o r   z s h ) 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 r c e s   b y   f i l e n a m e s ,   s t d i n ,   r e s o u r c e s   a n d


Question: What is Enforce Pod Security Standards with Namespace Labels?

Answer: Enforce Pod Security Standards with Namespace LabelsNamespaces can be labeled to enforce the Pod Security Standards. The three policies privileged, baseline and restricted broadly cover the security spectrum and are implemented by the Pod Security admission controller.Before you beginPod Security Admission was available by default in Kubernetes v1.23, as a beta. From version 1.25 onwards, Pod Security Admission is generally available.To check the version, enter kubectl version.Requiring the baseline Pod Security Standard with namespace labelsThis manifest defines a Namespace my-baseline-namespace that:Blocks any pods that don't satisfy the baseline policy requirements.Generates a user-facing warning and adds an audit annotation to any created pod that does not meet the restricted policy requirements.Pins the versions of the baseline and restricted policies to v1.34.apiVersion: v1 kind: Namespace metadata: name: my-baseline-namespace labels: pod-security.kubernetes.io/enforce: baseline pod-security.kubernetes.io/enforce-version: v1.34 # We are setting these to our _desired_ `enforce` level. pod-security.kubernetes.io/audit: restricted pod-security.kubernetes.io/audit-version: v1.34 pod-security.kubernetes.io/warn: restricted pod-security.kubernetes.io/warn-version: v1.34 Add labels to existing namespaces with kubectl labelNote:When an enforce policy (or version) label is added or changed, the admission plugin will test each pod in the namespace against the new policy. Violations are returned to the user as warnings.It is helpful to apply the --dry-run flag when initially evaluating security profile changes for namespaces. The Pod Security Standard checks will still be run in dry run mode, giving you information about how the new policy would treat existing pods, without actually updating a policy.kubectl label --dry-run=server --overwrite ns --all \ pod-security.kubernetes.io/enforce=baseline Applying to all namespacesIf you're just getting started with the Pod Security Standards, a suitable first step would be to configure all namespaces with audit annotations for a stricter level such as baseline:kubectl label --overwrite ns --all \ pod-security.kubernetes.io/audit=baseline \ pod-security.kubernetes.io/warn=baseline Note that this is not setting an enforce level, so that namespaces that haven't been explicitly evaluated can be distinguished. You can list namespaces without an explicitly set enforce level using this command:kubectl get namespaces --selector='!pod-security.kubernetes.io/enforce' Applying to a single namespaceYou can update a specific namespace as well. This command adds the enforce=restricted policy to my-existing-namespace, pinning the restricted policy version to v1.34.kubectl label --overwrite ns my-existing-namespace \ pod-security.kubernetes.io/enforce=restricted \ pod-security.kubernetes.io/enforce-version=v1.34


Question: How does Enforce Pod Security Standards with Namespace Labels work?

Answer: Enforce Pod Security Standards with Namespace LabelsNamespaces can be labeled to enforce the Pod Security Standards. The three policies privileged, baseline and restricted broadly cover the security spectrum and are implemented by the Pod Security admission controller.Before you beginPod Security Admission was available by default in Kubernetes v1.23, as a beta. From version 1.25 onwards, Pod Security Admission is generally available.To check the version, enter kubectl version.Requiring the baseline Pod Security Standard with namespace labelsThis manifest defines a Namespace my-baseline-namespace that:Blocks any pods that don't satisfy the baseline policy requirements.Generates a user-facing warning and adds an audit annotation to any created pod that does not meet the restricted policy requirements.Pins the versions of the baseline and restricted policies to v1.34.apiVersion: v1 kind: Namespace metadata: name: my-baseline-namespace labels: pod-security.kubernetes.io/enforce: baseline pod-security.kubernetes.io/enforce-version: v1.34 # We are setting these to our _desired_ `enforce` level. pod-security.kubernetes.io/audit: restricted pod-security.kubernetes.io/audit-version: v1.34 pod-security.kubernetes.io/warn: restricted pod-security.kubernetes.io/warn-version: v1.34 Add labels to existing namespaces with kubectl labelNote:When an enforce policy (or version) label is added or changed, the admission plugin will test each pod in the namespace against the new policy. Violations are returned to the user as warnings.It is helpful to apply the --dry-run flag when initially evaluating security profile changes for namespaces. The Pod Security Standard checks will still be run in dry run mode, giving you information about how the new policy would treat existing pods, without actually updating a policy.kubectl label --dry-run=server --overwrite ns --all \ pod-security.kubernetes.io/enforce=baseline Applying to all namespacesIf you're just getting started with the Pod Security Standards, a suitable first step would be to configure all namespaces with audit annotations for a stricter level such as baseline:kubectl label --overwrite ns --all \ pod-security.kubernetes.io/audit=baseline \ pod-security.kubernetes.io/warn=baseline Note that this is not setting an enforce level, so that namespaces that haven't been explicitly evaluated can be distinguished. You can list namespaces without an explicitly set enforce level using this command:kubectl get namespaces --selector='!pod-security.kubernetes.io/enforce' Applying to a single namespaceYou can update a specific namespace as well. This command adds the enforce=restricted policy to my-existing-namespace, pinning the restricted policy version to v1.34.kubectl label --overwrite ns my-existing-namespace \ pod-security.kubernetes.io/enforce=restricted \ pod-security.kubernetes.io/enforce-version=v1.34


Question: When would you use Enforce Pod Security Standards with Namespace Labels?

Answer: Enforce Pod Security Standards with Namespace LabelsNamespaces can be labeled to enforce the Pod Security Standards. The three policies privileged, baseline and restricted broadly cover the security spectrum and are implemented by the Pod Security admission controller.Before you beginPod Security Admission was available by default in Kubernetes v1.23, as a beta. From version 1.25 onwards, Pod Security Admission is generally available.To check the version, enter kubectl version.Requiring the baseline Pod Security Standard with namespace labelsThis manifest defines a Namespace my-baseline-namespace that:Blocks any pods that don't satisfy the baseline policy requirements.Generates a user-facing warning and adds an audit annotation to any created pod that does not meet the restricted policy requirements.Pins the versions of the baseline and restricted policies to v1.34.apiVersion: v1 kind: Namespace metadata: name: my-baseline-namespace labels: pod-security.kubernetes.io/enforce: baseline pod-security.kubernetes.io/enforce-version: v1.34 # We are setting these to our _desired_ `enforce` level. pod-security.kubernetes.io/audit: restricted pod-security.kubernetes.io/audit-version: v1.34 pod-security.kubernetes.io/warn: restricted pod-security.kubernetes.io/warn-version: v1.34 Add labels to existing namespaces with kubectl labelNote:When an enforce policy (or version) label is added or changed, the admission plugin will test each pod in the namespace against the new policy. Violations are returned to the user as warnings.It is helpful to apply the --dry-run flag when initially evaluating security profile changes for namespaces. The Pod Security Standard checks will still be run in dry run mode, giving you information about how the new policy would treat existing pods, without actually updating a policy.kubectl label --dry-run=server --overwrite ns --all \ pod-security.kubernetes.io/enforce=baseline Applying to all namespacesIf you're just getting started with the Pod Security Standards, a suitable first step would be to configure all namespaces with audit annotations for a stricter level such as baseline:kubectl label --overwrite ns --all \ pod-security.kubernetes.io/audit=baseline \ pod-security.kubernetes.io/warn=baseline Note that this is not setting an enforce level, so that namespaces that haven't been explicitly evaluated can be distinguished. You can list namespaces without an explicitly set enforce level using this command:kubectl get namespaces --selector='!pod-security.kubernetes.io/enforce' Applying to a single namespaceYou can update a specific namespace as well. This command adds the enforce=restricted policy to my-existing-namespace, pinning the restricted policy version to v1.34.kubectl label --overwrite ns my-existing-namespace \ pod-security.kubernetes.io/enforce=restricted \ pod-security.kubernetes.io/enforce-version=v1.34


Question: What are the benefits of Enforce Pod Security Standards with Namespace Labels?

Answer: Enforce Pod Security Standards with Namespace LabelsNamespaces can be labeled to enforce the Pod Security Standards. The three policies privileged, baseline and restricted broadly cover the security spectrum and are implemented by the Pod Security admission controller.Before you beginPod Security Admission was available by default in Kubernetes v1.23, as a beta. From version 1.25 onwards, Pod Security Admission is generally available.To check the version, enter kubectl version.Requiring the baseline Pod Security Standard with namespace labelsThis manifest defines a Namespace my-baseline-namespace that:Blocks any pods that don't satisfy the baseline policy requirements.Generates a user-facing warning and adds an audit annotation to any created pod that does not meet the restricted policy requirements.Pins the versions of the baseline and restricted policies to v1.34.apiVersion: v1 kind: Namespace metadata: name: my-baseline-namespace labels: pod-security.kubernetes.io/enforce: baseline pod-security.kubernetes.io/enforce-version: v1.34 # We are setting these to our _desired_ `enforce` level. pod-security.kubernetes.io/audit: restricted pod-security.kubernetes.io/audit-version: v1.34 pod-security.kubernetes.io/warn: restricted pod-security.kubernetes.io/warn-version: v1.34 Add labels to existing namespaces with kubectl labelNote:When an enforce policy (or version) label is added or changed, the admission plugin will test each pod in the namespace against the new policy. Violations are returned to the user as warnings.It is helpful to apply the --dry-run flag when initially evaluating security profile changes for namespaces. The Pod Security Standard checks will still be run in dry run mode, giving you information about how the new policy would treat existing pods, without actually updating a policy.kubectl label --dry-run=server --overwrite ns --all \ pod-security.kubernetes.io/enforce=baseline Applying to all namespacesIf you're just getting started with the Pod Security Standards, a suitable first step would be to configure all namespaces with audit annotations for a stricter level such as baseline:kubectl label --overwrite ns --all \ pod-security.kubernetes.io/audit=baseline \ pod-security.kubernetes.io/warn=baseline Note that this is not setting an enforce level, so that namespaces that haven't been explicitly evaluated can be distinguished. You can list namespaces without an explicitly set enforce level using this command:kubectl get namespaces --selector='!pod-security.kubernetes.io/enforce' Applying to a single namespaceYou can update a specific namespace as well. This command adds the enforce=restricted policy to my-existing-namespace, pinning the restricted policy version to v1.34.kubectl label --overwrite ns my-existing-namespace \ pod-security.kubernetes.io/enforce=restricted \ pod-security.kubernetes.io/enforce-version=v1.34


Question: What is Enforce Pod Security Standards with Namespace Labels?

Answer: N a m e s p a c e s   c a n   b e   l a b e l e d   t o   e n f o r c e   t h e   P o d   S e c u r i t y   S t a n d a r d s .   T h e   t h r e e   p o l i c i e s   p r i v i l e g e d ,   b a s e l i n e   a n d   r e s t r i c t e d   b r o a d l y   c o v e r   t h e   s e c u r i t y   s p e c t r u m   a n d   a r e   i m p l e m e n t e d   b y   t h e   P o d   S e c u r i t y   a d m i s s i o n   c o n t r o l l e r .


Question: What is Before you begin?

Answer: P o d   S e c u r i t y   A d m i s s i o n   w a s   a v a i l a b l e   b y   d e f a u l t   i n   K u b e r n e t e s   v 1 . 2 3 ,   a s   a   b e t a .   F r o m   v e r s i o n   1 . 2 5   o n w a r d s ,   P o d   S e c u r i t y   A d m i s s i o n   i s   g e n e r a l l y   a v a i l a b l e .   T o   c h e c k   t h e   v e r s i o n ,   e n t e r   k u b e c t l   v e r s i o n .


Question: What is Requiring the baseline Pod Security Standard with namespace labels?

Answer: T h i s   m a n i f e s t   d e f i n e s   a   N a m e s p a c e   m y - b a s e l i n e - n a m e s p a c e   t h a t :   B l o c k s   a n y   p o d s   t h a t   d o n ' t   s a t i s f y   t h e   b a s e l i n e   p o l i c y   r e q u i r e m e n t s . G e n e r a t e s   a   u s e r - f a c i n g   w a r n i n g   a n d   a d d s   a n   a u d i t   a n n o t a t i o n   t o   a n y   c r e a t e d   p o d   t h a t   d o e s   n o t   m e e t   t h e   r e s t r i c t e d   p o l i c y   r e q u i r e m e n t s . P i n s   t h e   v e r s i o n s   o f   t h e   b a s e l i n e   a n d   r e s t r i c t e d   p o l i c i e s   t o   v 1 . 3 4 .   a p i V e r s i o n :   v 1   k i n d :   N a m e s p a c e   m e t a d a t a :   n a m e :   m y - b a s e l i n e - n a m e s p a c e   l a b e l s :   p o d - s e c u r i t y . k u b e r n e t e s . i o / e n f o r c e :   b a s e l i n e   p o d - s e c u r i t y . k u b e r n e t e s . i o / e n f o r c e - v e r s i o n :   v 1 . 3 4   #   W e   a r e   s e t t i n g   t h e s e   t o   o u r   _ d e s i r e d _   ` e n f o r c e `   l e v e l .   p o d - s e c u r i t y . k u b e r n e t e s . i o / a u d i t :   r e s t r i c t e d   p o d - s e c u r i t y . k u b e r n e t e s . i o / a u d i t - v e r s i o n :   v 1 . 3 4   p o d - s e c u r i t y . k u b e r n e t e s . i o / w a r n :   r e s t r i c t e d   p o d - s e c u r i t y . k u b e r n e t e s . i o / w a r n - v e r s i o n :   v 1 . 3 4


Question: What is Note:?

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


Question: What is Applying to all namespaces?

Answer: I f   y o u ' r e   j u s t   g e t t i n g   s t a r t e d   w i t h   t h e   P o d   S e c u r i t y   S t a n d a r d s ,   a   s u i t a b l e   f i r s t   s t e p   w o u l d   b e   t o   c o n f i g u r e   a l l   n a m e s p a c e s   w i t h   a u d i t   a n n o t a t i o n s   f o r   a   s t r i c t e r   l e v e l   s u c h   a s   b a s e l i n e :   k u b e c t l   l a b e l   - - o v e r w r i t e   n s   - - a l l   \   p o d - s e c u r i t y . k u b e r n e t e s . i o / a u d i t = b a s e l i n e   \   p o d - s e c u r i t y . k u b e r n e t e s . i o / w a r n = b a s e l i n e   N o t e   t h a t   t h i s   i s   n o t   s e t t i n g   a n   e n f o r c e   l e v e l ,   s o   t h a t   n a m e s p a c e s   t h a t   h a v e n ' t   b e e n   e x p l i c i t l y   e v a l u a t e d   c a n   b e   d i s t i n g u i s h e d .   Y o u   c a n   l i s t   n a m e s p a c e s   w i t h o u t   a n   e x p l i c i t l y   s e t   e n f o r c e   l e v e l   u s i n g   t h i s   c o m m a n d :   k u b e c t l   g e t   n a m e s p a c e s   - - s e l e c t o r = ' ! p o d - s e c u r i t y . k u b e r n e t e s . i o / e n f o r c e '


Question: What is Applying to a single namespace?

Answer: Y o u   c a n   u p d a t e   a   s p e c i f i c   n a m e s p a c e   a s   w e l l .   T h i s   c o m m a n d   a d d s   t h e   e n f o r c e = r e s t r i c t e d   p o l i c y   t o   m y - e x i s t i n g - n a m e s p a c e ,   p i n n i n g   t h e   r e s t r i c t e d   p o l i c y   v e r s i o n   t o   v 1 . 3 4 .   k u b e c t l   l a b e l   - - o v e r w r i t e   n s   m y - e x i s t i n g - n a m e s p a c e   \   p o d - s e c u r i t y . k u b e r n e t e s . i o / e n f o r c e = r e s t r i c t e d   \   p o d - s e c u r i t y . k u b e r n e t e s . i o / e n f o r c e - v e r s i o n = v 1 . 3 4


Question: What is Process ID Limits And Reservations?

Answer: Process ID Limits And ReservationsFEATURE STATE: Kubernetes v1.20 [stable]Kubernetes allow you to limit the number of process IDs (PIDs) that a Pod can use. You can also reserve a number of allocatable PIDs for each node for use by the operating system and daemons (rather than by Pods).Process IDs (PIDs) are a fundamental resource on nodes. It is trivial to hit the task limit without hitting any other resource limits, which can then cause instability to a host machine.Cluster administrators require mechanisms to ensure that Pods running in the cluster cannot induce PID exhaustion that prevents host daemons (such as the kubelet or kube-proxy, and potentially also the container runtime) from running. In addition, it is important to ensure that PIDs are limited among Pods in order to ensure they have limited impact on other workloads on the same node.Note:On certain Linux installations, the operating system sets the PIDs limit to a low default, such as 32768. Consider raising the value of /proc/sys/kernel/pid_max.You can configure a kubelet to limit the number of PIDs a given Pod can consume. For example, if your node's host OS is set to use a maximum of 262144 PIDs and expect to host less than 250 Pods, one can give each Pod a budget of 1000 PIDs to prevent using up that node's overall number of available PIDs. If the admin wants to overcommit PIDs similar to CPU or memory, they may do so as well with some additional risks. Either way, a single Pod will not be able to bring the whole machine down. This kind of resource limiting helps to prevent simple fork bombs from affecting operation of an entire cluster.Per-Pod PID limiting allows administrators to protect one Pod from another, but does not ensure that all Pods scheduled onto that host are unable to impact the node overall. Per-Pod limiting also does not protect the node agents themselves from PID exhaustion.You can also reserve an amount of PIDs for node overhead, separate from the allocation to Pods. This is similar to how you can reserve CPU, memory, or other resources for use by the operating system and other facilities outside of Pods and their containers.PID limiting is an important sibling to compute resource requests and limits. However, you specify it in a different way: rather than defining a Pod's resource limit in the .spec for a Pod, you configure the limit as a setting on the kubelet. Pod-defined PID limits are not currently supported.Caution:This means that the limit that applies to a Pod may be different depending on where the Pod is scheduled. To make things simple, it's easiest if all Nodes use the same PID resource limits and reservations.Node PID limitsKubernetes allows you to reserve a number of process IDs for the system use. To configure the reservation, use the parameter pid=<number> in the --system-reserved and --kube-reserved command line options to the kubelet. The value you specified declares that the specified number of process IDs will be reserved for the system as


Question: How does Process ID Limits And Reservations work?

Answer: Process ID Limits And ReservationsFEATURE STATE: Kubernetes v1.20 [stable]Kubernetes allow you to limit the number of process IDs (PIDs) that a Pod can use. You can also reserve a number of allocatable PIDs for each node for use by the operating system and daemons (rather than by Pods).Process IDs (PIDs) are a fundamental resource on nodes. It is trivial to hit the task limit without hitting any other resource limits, which can then cause instability to a host machine.Cluster administrators require mechanisms to ensure that Pods running in the cluster cannot induce PID exhaustion that prevents host daemons (such as the kubelet or kube-proxy, and potentially also the container runtime) from running. In addition, it is important to ensure that PIDs are limited among Pods in order to ensure they have limited impact on other workloads on the same node.Note:On certain Linux installations, the operating system sets the PIDs limit to a low default, such as 32768. Consider raising the value of /proc/sys/kernel/pid_max.You can configure a kubelet to limit the number of PIDs a given Pod can consume. For example, if your node's host OS is set to use a maximum of 262144 PIDs and expect to host less than 250 Pods, one can give each Pod a budget of 1000 PIDs to prevent using up that node's overall number of available PIDs. If the admin wants to overcommit PIDs similar to CPU or memory, they may do so as well with some additional risks. Either way, a single Pod will not be able to bring the whole machine down. This kind of resource limiting helps to prevent simple fork bombs from affecting operation of an entire cluster.Per-Pod PID limiting allows administrators to protect one Pod from another, but does not ensure that all Pods scheduled onto that host are unable to impact the node overall. Per-Pod limiting also does not protect the node agents themselves from PID exhaustion.You can also reserve an amount of PIDs for node overhead, separate from the allocation to Pods. This is similar to how you can reserve CPU, memory, or other resources for use by the operating system and other facilities outside of Pods and their containers.PID limiting is an important sibling to compute resource requests and limits. However, you specify it in a different way: rather than defining a Pod's resource limit in the .spec for a Pod, you configure the limit as a setting on the kubelet. Pod-defined PID limits are not currently supported.Caution:This means that the limit that applies to a Pod may be different depending on where the Pod is scheduled. To make things simple, it's easiest if all Nodes use the same PID resource limits and reservations.Node PID limitsKubernetes allows you to reserve a number of process IDs for the system use. To configure the reservation, use the parameter pid=<number> in the --system-reserved and --kube-reserved command line options to the kubelet. The value you specified declares that the specified number of process IDs will be reserved for the system as


Question: When would you use Process ID Limits And Reservations?

Answer: Process ID Limits And ReservationsFEATURE STATE: Kubernetes v1.20 [stable]Kubernetes allow you to limit the number of process IDs (PIDs) that a Pod can use. You can also reserve a number of allocatable PIDs for each node for use by the operating system and daemons (rather than by Pods).Process IDs (PIDs) are a fundamental resource on nodes. It is trivial to hit the task limit without hitting any other resource limits, which can then cause instability to a host machine.Cluster administrators require mechanisms to ensure that Pods running in the cluster cannot induce PID exhaustion that prevents host daemons (such as the kubelet or kube-proxy, and potentially also the container runtime) from running. In addition, it is important to ensure that PIDs are limited among Pods in order to ensure they have limited impact on other workloads on the same node.Note:On certain Linux installations, the operating system sets the PIDs limit to a low default, such as 32768. Consider raising the value of /proc/sys/kernel/pid_max.You can configure a kubelet to limit the number of PIDs a given Pod can consume. For example, if your node's host OS is set to use a maximum of 262144 PIDs and expect to host less than 250 Pods, one can give each Pod a budget of 1000 PIDs to prevent using up that node's overall number of available PIDs. If the admin wants to overcommit PIDs similar to CPU or memory, they may do so as well with some additional risks. Either way, a single Pod will not be able to bring the whole machine down. This kind of resource limiting helps to prevent simple fork bombs from affecting operation of an entire cluster.Per-Pod PID limiting allows administrators to protect one Pod from another, but does not ensure that all Pods scheduled onto that host are unable to impact the node overall. Per-Pod limiting also does not protect the node agents themselves from PID exhaustion.You can also reserve an amount of PIDs for node overhead, separate from the allocation to Pods. This is similar to how you can reserve CPU, memory, or other resources for use by the operating system and other facilities outside of Pods and their containers.PID limiting is an important sibling to compute resource requests and limits. However, you specify it in a different way: rather than defining a Pod's resource limit in the .spec for a Pod, you configure the limit as a setting on the kubelet. Pod-defined PID limits are not currently supported.Caution:This means that the limit that applies to a Pod may be different depending on where the Pod is scheduled. To make things simple, it's easiest if all Nodes use the same PID resource limits and reservations.Node PID limitsKubernetes allows you to reserve a number of process IDs for the system use. To configure the reservation, use the parameter pid=<number> in the --system-reserved and --kube-reserved command line options to the kubelet. The value you specified declares that the specified number of process IDs will be reserved for the system as


Question: What are the benefits of Process ID Limits And Reservations?

Answer: Process ID Limits And ReservationsFEATURE STATE: Kubernetes v1.20 [stable]Kubernetes allow you to limit the number of process IDs (PIDs) that a Pod can use. You can also reserve a number of allocatable PIDs for each node for use by the operating system and daemons (rather than by Pods).Process IDs (PIDs) are a fundamental resource on nodes. It is trivial to hit the task limit without hitting any other resource limits, which can then cause instability to a host machine.Cluster administrators require mechanisms to ensure that Pods running in the cluster cannot induce PID exhaustion that prevents host daemons (such as the kubelet or kube-proxy, and potentially also the container runtime) from running. In addition, it is important to ensure that PIDs are limited among Pods in order to ensure they have limited impact on other workloads on the same node.Note:On certain Linux installations, the operating system sets the PIDs limit to a low default, such as 32768. Consider raising the value of /proc/sys/kernel/pid_max.You can configure a kubelet to limit the number of PIDs a given Pod can consume. For example, if your node's host OS is set to use a maximum of 262144 PIDs and expect to host less than 250 Pods, one can give each Pod a budget of 1000 PIDs to prevent using up that node's overall number of available PIDs. If the admin wants to overcommit PIDs similar to CPU or memory, they may do so as well with some additional risks. Either way, a single Pod will not be able to bring the whole machine down. This kind of resource limiting helps to prevent simple fork bombs from affecting operation of an entire cluster.Per-Pod PID limiting allows administrators to protect one Pod from another, but does not ensure that all Pods scheduled onto that host are unable to impact the node overall. Per-Pod limiting also does not protect the node agents themselves from PID exhaustion.You can also reserve an amount of PIDs for node overhead, separate from the allocation to Pods. This is similar to how you can reserve CPU, memory, or other resources for use by the operating system and other facilities outside of Pods and their containers.PID limiting is an important sibling to compute resource requests and limits. However, you specify it in a different way: rather than defining a Pod's resource limit in the .spec for a Pod, you configure the limit as a setting on the kubelet. Pod-defined PID limits are not currently supported.Caution:This means that the limit that applies to a Pod may be different depending on where the Pod is scheduled. To make things simple, it's easiest if all Nodes use the same PID resource limits and reservations.Node PID limitsKubernetes allows you to reserve a number of process IDs for the system use. To configure the reservation, use the parameter pid=<number> in the --system-reserved and --kube-reserved command line options to the kubelet. The value you specified declares that the specified number of process IDs will be reserved for the system as


Question: What is Process ID Limits And Reservations?

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


Question: What is Note:?

Answer: Y o u   c a n   c o n f i g u r e   a   k u b e l e t   t o   l i m i t   t h e   n u m b e r   o f   P I D s   a   g i v e n   P o d   c a n   c o n s u m e .   F o r   e x a m p l e ,   i f   y o u r   n o d e ' s   h o s t   O S   i s   s e t   t o   u s e   a   m a x i m u m   o f   2 6 2 1 4 4   P I D s   a n d   e x p e c t   t o   h o s t   l e s s   t h a n   2 5 0   P o d s ,   o n e   c a n   g i v e   e a c h   P o d   a   b u d g e t   o f   1 0 0 0   P I D s   t o   p r e v e n t   u s i n g   u p   t h a t   n o d e ' s   o v e r a l l   n u m b e r   o f   a v a i l a b l e   P I D s .   I f   t h e   a d m i n   w a n t s   t o   o v e r c o m m i t   P I D s   s i m i l a r   t o   C P U   o r   m e m o r y ,   t h e y   m a y   d o   s o   a s   w e l l   w i t h   s o m e   a d d i t i o n a l   r i s k s .   E i t h e r   w a y ,   a   s i n g l e   P o d   w i l l   n o t   b e   a b l e   t o   b r i n g   t h e   w h o l e   m a c h i n e   d o w n .   T h i s   k i n d   o f   r e s o u r c e   l i m i t i n g   h e l p s   t o   p r e v e n t   s i m p l e   f o r k   b o m b s   f r o m   a f f e c t i n g   o p e r a t i o n   o f   a n   e n t i r e   c l u s t e r .   P e r - P o d   P I D   l i m i t i n g   a l l o w s   a d m i n i s t r a t o r s   t o   p r o t e c t   o n e   P o d   f r o m   a n o t h e r ,   b u t   d o e s   n o t   e n s u r e   t h a t   a l l   P o d s   s c h e d u l e d   o n t o   t h a t   h o s t   a r e   u n a b l e   t o   i m p a c t   t h e   n o d e   o v e r a l l .   P e r - P o d   l i m i t i n g   a l s o   d o e s   n o t   p r o t e c t   t h e   n o d e   a g e n t s   t h e m s e l v e s   f r o m   P I D   e x h a u s t i o n .   Y o u   c a n   a l s o   r e s e r v e   a n   a m o u n t   o f   P I D s   f o r   n o d e   o v e r h e a d ,   s e p a r a t e   f r o m   t h e   a l l o c a t i o n   t o   P o d s .   T h i s   i s   s i m i l a r   t o   h o w   y o u   c a n   r e s e


Question: What is Node PID limits?

Answer: K u b e r n e t e s   a l l o w s   y o u   t o   r e s e r v e   a   n u m b e r   o f   p r o c e s s   I D s   f o r   t h e   s y s t e m   u s e .   T o   c o n f i g u r e   t h e   r e s e r v a t i o n ,   u s e   t h e   p a r a m e t e r   p i d = < n u m b e r >   i n   t h e   - - s y s t e m - r e s e r v e d   a n d   - - k u b e - r e s e r v e d   c o m m a n d   l i n e   o p t i o n s   t o   t h e   k u b e l e t .   T h e   v a l u e   y o u   s p e c i f i e d   d e c l a r e s   t h a t   t h e   s p e c i f i e d   n u m b e r   o f   p r o c e s s   I D s   w i l l   b e   r e s e r v e d   f o r   t h e   s y s t e m   a s   a   w h o l e   a n d   f o r   K u b e r n e t e s   s y s t e m   d a e m o n s   r e s p e c t i v e l y .


Question: What is Pod PID limits?

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


Question: What is PID based eviction?

Answer: Y o u   c a n   c o n f i g u r e   k u b e l e t   t o   s t a r t   t e r m i n a t i n g   a   P o d   w h e n   i t   i s   m i s b e h a v i n g   a n d   c o n s u m i n g   a b n o r m a l   a m o u n t   o f   r e s o u r c e s .   T h i s   f e a t u r e   i s   c a l l e d   e v i c t i o n .   Y o u   c a n   C o n f i g u r e   O u t   o f   R e s o u r c e   H a n d l i n g   f o r   v a r i o u s   e v i c t i o n   s i g n a l s .   U s e   p i d . a v a i l a b l e   e v i c t i o n   s i g n a l   t o   c o n f i g u r e   t h e   t h r e s h o l d   f o r   n u m b e r   o f   P I D s   u s e d   b y   P o d .   Y o u   c a n   s e t   s o f t   a n d   h a r d   e v i c t i o n   p o l i c i e s .   H o w e v e r ,   e v e n   w i t h   t h e   h a r d   e v i c t i o n   p o l i c y ,   i f   t h e   n u m b e r   o f   P I D s   g r o w i n g   v e r y   f a s t ,   n o d e   c a n   s t i l l   g e t   i n t o   u n s t a b l e   s t a t e   b y   h i t t i n g   t h e   n o d e   P I D s   l i m i t .   E v i c t i o n   s i g n a l   v a l u e   i s   c a l c u l a t e d   p e r i o d i c a l l y   a n d   d o e s   N O T   e n f o r c e   t h e   l i m i t .   P I D   l i m i t i n g   -   p e r   P o d   a n d   p e r   N o d e   s e t s   t h e   h a r d   l i m i t .   O n c e   t h e   l i m i t   i s   h i t ,   w o r k l o a d   w i l l   s t a r t   e x p e r i e n c i n g   f a i l u r e s   w h e n   t r y i n g   t o   g e t   a   n e w   P I D .   I t   m a y   o r   m a y   n o t   l e a d   t o   r e s c h e d u l i n g   o f   a   P o d ,   d e p e n d i n g   o n   h o w   w o r k l o a d   r e a c t s   o n   t h e s e   f a i l u r e s   a n d   h o w   l i v e n e s s   a n d   r e a d i n e s s   p r o b e s   a r e   c o n f i g u r e d   f o r   t h e   P o d .   H o w e v e r ,   i f   l i m i t s   w e r e   s e t   c o r r e c t l y ,   y o u   c a n   g u a r a n t e e   t h a t   o t h e r   P o d s   w o r k l o a


Question: What is What's next?

Answer: R e f e r   t o   t h e   P I D   L i m i t i n g   e n h a n c e m e n t   d o c u m e n t   f o r   m o r e   i n f o r m a t i o n . F o r   h i s t o r i c a l   c o n t e x t ,   r e a d   P r o c e s s   I D   L i m i t i n g   f o r   S t a b i l i t y   I m p r o v e m e n t s   i n   K u b e r n e t e s   1 . 1 4 . R e a d   M a n a g i n g   R e s o u r c e s   f o r   C o n t a i n e r s . L e a r n   h o w   t o   C o n f i g u r e   O u t   o f   R e s o u r c e   H a n d l i n g .


Question: What is kubectl create clusterrolebinding?

Answer: kubectl create clusterrolebindingSynopsisCreate a cluster role binding for a particular cluster role.kubectl create clusterrolebinding NAME --clusterrole=NAME [--user=username] [--group=groupname] [--serviceaccount=namespace:serviceaccountname] [--dry-run=server|client|none] Examples # Create a cluster role binding for user1, user2, and group1 using the cluster-admin cluster role kubectl create clusterrolebinding cluster-admin --clusterrole=cluster-admin --user=user1 --user=user2 --group=group1 Options--allow-missing-template-keys Default: trueIf true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.--clusterrole stringClusterRole this ClusterRoleBinding should reference--dry-run string[="unchanged"] Default: "none"Must be "none", "server", or "client". If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.--field-manager string Default: "kubectl-create"Name of the manager used to track field ownership.--group stringsGroups to bind to the clusterrole. The flag can be repeated to add multiple groups.-h, --helphelp for clusterrolebinding-o, --output stringOutput format. One of: (json, yaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).--save-configIf true, the configuration of current object will be saved in its annotation. Otherwise, the annotation will be unchanged. This flag is useful when you want to perform kubectl apply on this object in the future.--serviceaccount stringsService accounts to bind to the clusterrole, in the format <namespace>:<name>. The flag can be repeated to add multiple service accounts.--show-managed-fieldsIf true, keep the managedFields when printing objects in JSON or YAML format.--template stringTemplate string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].--user stringsUsernames to bind to the clusterrole. The flag can be repeated to add multiple users.--validate string[="strict"] Default: "strict"Must be one of: strict (or true), warn, ignore (or false). "true" or "strict" will use a schema to validate the input and fail the request if invalid. It will perform server side validation if ServerSideFieldValidation is enabled on the api-server, but will fall back to less reliable client-side validation if not. "warn" will warn about unknown or duplicate fields without blocking the request if server-side field validation is enabled on the API server, and behave as "ignore" otherwise. "false" or "ignore" will not perform any schema validation, silently dropping any unknown or duplicate fields.Parent Options Inherited--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup t


Question: How does kubectl create clusterrolebinding work?

Answer: kubectl create clusterrolebindingSynopsisCreate a cluster role binding for a particular cluster role.kubectl create clusterrolebinding NAME --clusterrole=NAME [--user=username] [--group=groupname] [--serviceaccount=namespace:serviceaccountname] [--dry-run=server|client|none] Examples # Create a cluster role binding for user1, user2, and group1 using the cluster-admin cluster role kubectl create clusterrolebinding cluster-admin --clusterrole=cluster-admin --user=user1 --user=user2 --group=group1 Options--allow-missing-template-keys Default: trueIf true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.--clusterrole stringClusterRole this ClusterRoleBinding should reference--dry-run string[="unchanged"] Default: "none"Must be "none", "server", or "client". If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.--field-manager string Default: "kubectl-create"Name of the manager used to track field ownership.--group stringsGroups to bind to the clusterrole. The flag can be repeated to add multiple groups.-h, --helphelp for clusterrolebinding-o, --output stringOutput format. One of: (json, yaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).--save-configIf true, the configuration of current object will be saved in its annotation. Otherwise, the annotation will be unchanged. This flag is useful when you want to perform kubectl apply on this object in the future.--serviceaccount stringsService accounts to bind to the clusterrole, in the format <namespace>:<name>. The flag can be repeated to add multiple service accounts.--show-managed-fieldsIf true, keep the managedFields when printing objects in JSON or YAML format.--template stringTemplate string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].--user stringsUsernames to bind to the clusterrole. The flag can be repeated to add multiple users.--validate string[="strict"] Default: "strict"Must be one of: strict (or true), warn, ignore (or false). "true" or "strict" will use a schema to validate the input and fail the request if invalid. It will perform server side validation if ServerSideFieldValidation is enabled on the api-server, but will fall back to less reliable client-side validation if not. "warn" will warn about unknown or duplicate fields without blocking the request if server-side field validation is enabled on the API server, and behave as "ignore" otherwise. "false" or "ignore" will not perform any schema validation, silently dropping any unknown or duplicate fields.Parent Options Inherited--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup t


Question: When would you use kubectl create clusterrolebinding?

Answer: kubectl create clusterrolebindingSynopsisCreate a cluster role binding for a particular cluster role.kubectl create clusterrolebinding NAME --clusterrole=NAME [--user=username] [--group=groupname] [--serviceaccount=namespace:serviceaccountname] [--dry-run=server|client|none] Examples # Create a cluster role binding for user1, user2, and group1 using the cluster-admin cluster role kubectl create clusterrolebinding cluster-admin --clusterrole=cluster-admin --user=user1 --user=user2 --group=group1 Options--allow-missing-template-keys Default: trueIf true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.--clusterrole stringClusterRole this ClusterRoleBinding should reference--dry-run string[="unchanged"] Default: "none"Must be "none", "server", or "client". If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.--field-manager string Default: "kubectl-create"Name of the manager used to track field ownership.--group stringsGroups to bind to the clusterrole. The flag can be repeated to add multiple groups.-h, --helphelp for clusterrolebinding-o, --output stringOutput format. One of: (json, yaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).--save-configIf true, the configuration of current object will be saved in its annotation. Otherwise, the annotation will be unchanged. This flag is useful when you want to perform kubectl apply on this object in the future.--serviceaccount stringsService accounts to bind to the clusterrole, in the format <namespace>:<name>. The flag can be repeated to add multiple service accounts.--show-managed-fieldsIf true, keep the managedFields when printing objects in JSON or YAML format.--template stringTemplate string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].--user stringsUsernames to bind to the clusterrole. The flag can be repeated to add multiple users.--validate string[="strict"] Default: "strict"Must be one of: strict (or true), warn, ignore (or false). "true" or "strict" will use a schema to validate the input and fail the request if invalid. It will perform server side validation if ServerSideFieldValidation is enabled on the api-server, but will fall back to less reliable client-side validation if not. "warn" will warn about unknown or duplicate fields without blocking the request if server-side field validation is enabled on the API server, and behave as "ignore" otherwise. "false" or "ignore" will not perform any schema validation, silently dropping any unknown or duplicate fields.Parent Options Inherited--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup t


Question: What are the benefits of kubectl create clusterrolebinding?

Answer: kubectl create clusterrolebindingSynopsisCreate a cluster role binding for a particular cluster role.kubectl create clusterrolebinding NAME --clusterrole=NAME [--user=username] [--group=groupname] [--serviceaccount=namespace:serviceaccountname] [--dry-run=server|client|none] Examples # Create a cluster role binding for user1, user2, and group1 using the cluster-admin cluster role kubectl create clusterrolebinding cluster-admin --clusterrole=cluster-admin --user=user1 --user=user2 --group=group1 Options--allow-missing-template-keys Default: trueIf true, ignore any errors in templates when a field or map key is missing in the template. Only applies to golang and jsonpath output formats.--clusterrole stringClusterRole this ClusterRoleBinding should reference--dry-run string[="unchanged"] Default: "none"Must be "none", "server", or "client". If client strategy, only print the object that would be sent, without sending it. If server strategy, submit server-side request without persisting the resource.--field-manager string Default: "kubectl-create"Name of the manager used to track field ownership.--group stringsGroups to bind to the clusterrole. The flag can be repeated to add multiple groups.-h, --helphelp for clusterrolebinding-o, --output stringOutput format. One of: (json, yaml, name, go-template, go-template-file, template, templatefile, jsonpath, jsonpath-as-json, jsonpath-file).--save-configIf true, the configuration of current object will be saved in its annotation. Otherwise, the annotation will be unchanged. This flag is useful when you want to perform kubectl apply on this object in the future.--serviceaccount stringsService accounts to bind to the clusterrole, in the format <namespace>:<name>. The flag can be repeated to add multiple service accounts.--show-managed-fieldsIf true, keep the managedFields when printing objects in JSON or YAML format.--template stringTemplate string or path to template file to use when -o=go-template, -o=go-template-file. The template format is golang templates [http://golang.org/pkg/text/template/#pkg-overview].--user stringsUsernames to bind to the clusterrole. The flag can be repeated to add multiple users.--validate string[="strict"] Default: "strict"Must be one of: strict (or true), warn, ignore (or false). "true" or "strict" will use a schema to validate the input and fail the request if invalid. It will perform server side validation if ServerSideFieldValidation is enabled on the api-server, but will fall back to less reliable client-side validation if not. "warn" will warn about unknown or duplicate fields without blocking the request if server-side field validation is enabled on the API server, and behave as "ignore" otherwise. "false" or "ignore" will not perform any schema validation, silently dropping any unknown or duplicate fields.Parent Options Inherited--as stringUsername to impersonate for the operation. User could be a regular user or a service account in a namespace.--as-group stringsGroup t


Question: What is Synopsis?

Answer: C r e a t e   a   c l u s t e r   r o l e   b i n d i n g   f o r   a   p a r t i c u l a r   c l u s t e r   r o l e .   k u b e c t l   c r e a t e   c l u s t e r r o l e b i n d i n g   N A M E   - - c l u s t e r r o l e = N A M E   [ - - u s e r = u s e r n a m e ]   [ - - g r o u p = g r o u p n a m e ]   [ - - s e r v i c e a c c o u n t = n a m e s p a c e : s e r v i c e a c c o u n t n a m e ]   [ - - d r y - r u n = s e r v e r | c l i e n t | n o n e ]


Question: What is Examples?

Answer: #   C r e a t e   a   c l u s t e r   r o l e   b i n d i n g   f o r   u s e r 1 ,   u s e r 2 ,   a n d   g r o u p 1   u s i n g   t h e   c l u s t e r - a d m i n   c l u s t e r   r o l e   k u b e c t l   c r e a t e   c l u s t e r r o l e b i n d i n g   c l u s t e r - a d m i n   - - c l u s t e r r o l e = c l u s t e r - a d m i n   - - u s e r = u s e r 1   - - u s e r = u s e r 2   - - g r o u p = g r o u p 1


Question: What is Options?

Answer: I f   t r u e ,   i g n o r e   a n y   e r r o r s   i n   t e m p l a t e s   w h e n   a   f i e l d   o r   m a p   k e y   i s   m i s s i n g   i n   t h e   t e m p l a t e .   O n l y   a p p l i e s   t o   g o l a n g   a n d   j s o n p a t h   o u t p u t   f o r m a t s .   C l u s t e r R o l e   t h i s   C l u s t e r R o l e B i n d i n g   s h o u l d   r e f e r e n c e   M u s t   b e   " n o n e " ,   " s e r v e r " ,   o r   " c l i e n t " .   I f   c l i e n t   s t r a t e g y ,   o n l y   p r i n t   t h e   o b j e c t   t h a t   w o u l d   b e   s e n t ,   w i t h o u t   s e n d i n g   i t .   I f   s e r v e r   s t r a t e g y ,   s u b m i t   s e r v e r - s i d e   r e q u e s t   w i t h o u t   p e r s i s t i n g   t h e   r e s o u r c e .   N a m e   o f   t h e   m a n a g e r   u s e d   t o   t r a c k   f i e l d   o w n e r s h i p .   G r o u p s   t o   b i n d   t o   t h e   c l u s t e r r o l e .   T h e   f l a g   c a n   b e   r e p e a t e d   t o   a d d   m u l t i p l e   g r o u p s .   h e l p   f o r   c l u s t e r r o l e b i n d i n g   O u t p u t   f o r m a t .   O n e   o f :   ( j s o n ,   y a m l ,   n a m e ,   g o - t e m p l a t e ,   g o - t e m p l a t e - f i l e ,   t e m p l a t e ,   t e m p l a t e f i l e ,   j s o n p a t h ,   j s o n p a t h - a s - j s o n ,   j s o n p a t h - f i l e ) .   I f   t r u e ,   t h e   c o n f i g u r a t i o n   o f   c u r r e n t   o b j e c t   w i l l   b e   s a v e d   i n   i t s   a n n o t a t i o n .   O t h e r w i s e ,   t h e   a n n o t a t i o n   w i l l   b e   u n c h a n g e d .   T h i s   f l a g   i s   u s e f u l   w h e n   y o u   w a n t   t o   p e r f o r m   k u b e c t l   a p p l y   o n   t h i s   o b j e c t   i n   t h e   f u t u r e .   S e r v i c e   a c c o u n t s   t o   b i n d   t o   t h e   c l u s t e r r o l e ,   i n   t h e   f o r m a t   < n a m e s p a c e > : < n a m e > .   T h e   f l a


Question: What is Parent Options Inherited?

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   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   b a s i c   a u t h e n t i c a t


Question: What is See Also?

Answer: 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   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 Mixed Version Proxy?

Answer: Mixed Version ProxyFEATURE STATE: Kubernetes v1.28 [alpha] (enabled by default: false)Kubernetes 1.34 includes an alpha feature that lets an API Server proxy a resource requests to other peer API servers. This is useful when there are multiple API servers running different versions of Kubernetes in one cluster (for example, during a long-lived rollout to a new release of Kubernetes).This enables cluster administrators to configure highly available clusters that can be upgraded more safely, by directing resource requests (made during the upgrade) to the correct kube-apiserver. That proxying prevents users from seeing unexpected 404 Not Found errors that stem from the upgrade process.This mechanism is called the Mixed Version Proxy.Enabling the Mixed Version ProxyEnsure that UnknownVersionInteroperabilityProxy feature gate is enabled when you start the API Server:kube-apiserver \ --feature-gates=UnknownVersionInteroperabilityProxy=true \ # required command line arguments for this feature --peer-ca-file=<path to kube-apiserver CA cert> --proxy-client-cert-file=<path to aggregator proxy cert>, --proxy-client-key-file=<path to aggregator proxy key>, --requestheader-client-ca-file=<path to aggregator CA cert>, # requestheader-allowed-names can be set to blank to allow any Common Name --requestheader-allowed-names=<valid Common Names to verify proxy client cert against>, # optional flags for this feature --peer-advertise-ip=`IP of this kube-apiserver that should be used by peers to proxy requests` --peer-advertise-port=`port of this kube-apiserver that should be used by peers to proxy requests` # …and other flags as usual Proxy transport and authentication between API serversThe source kube-apiserver reuses the existing APIserver client authentication flags --proxy-client-cert-file and --proxy-client-key-file to present its identity that will be verified by its peer (the destination kube-apiserver). The destination API server verifies that peer connection based on the configuration you specify using the --requestheader-client-ca-file command line argument.To authenticate the destination server's serving certs, you must configure a certificate authority bundle by specifying the --peer-ca-file command line argument to the source API server.Configuration for peer API server connectivityTo set the network location of a kube-apiserver that peers will use to proxy requests, use the --peer-advertise-ip and --peer-advertise-port command line arguments to kube-apiserver or specify these fields in the API server configuration file. If these flags are unspecified, peers will use the value from either --advertise-address or --bind-address command line argument to the kube-apiserver. If those too, are unset, the host's default interface is used.Mixed version proxyingWhen you enable mixed version proxying, the aggregation layer loads a special filter that does the following:When a resource request reaches an API server that cannot serve that API (either because it is


Question: How does Mixed Version Proxy work?

Answer: Mixed Version ProxyFEATURE STATE: Kubernetes v1.28 [alpha] (enabled by default: false)Kubernetes 1.34 includes an alpha feature that lets an API Server proxy a resource requests to other peer API servers. This is useful when there are multiple API servers running different versions of Kubernetes in one cluster (for example, during a long-lived rollout to a new release of Kubernetes).This enables cluster administrators to configure highly available clusters that can be upgraded more safely, by directing resource requests (made during the upgrade) to the correct kube-apiserver. That proxying prevents users from seeing unexpected 404 Not Found errors that stem from the upgrade process.This mechanism is called the Mixed Version Proxy.Enabling the Mixed Version ProxyEnsure that UnknownVersionInteroperabilityProxy feature gate is enabled when you start the API Server:kube-apiserver \ --feature-gates=UnknownVersionInteroperabilityProxy=true \ # required command line arguments for this feature --peer-ca-file=<path to kube-apiserver CA cert> --proxy-client-cert-file=<path to aggregator proxy cert>, --proxy-client-key-file=<path to aggregator proxy key>, --requestheader-client-ca-file=<path to aggregator CA cert>, # requestheader-allowed-names can be set to blank to allow any Common Name --requestheader-allowed-names=<valid Common Names to verify proxy client cert against>, # optional flags for this feature --peer-advertise-ip=`IP of this kube-apiserver that should be used by peers to proxy requests` --peer-advertise-port=`port of this kube-apiserver that should be used by peers to proxy requests` # …and other flags as usual Proxy transport and authentication between API serversThe source kube-apiserver reuses the existing APIserver client authentication flags --proxy-client-cert-file and --proxy-client-key-file to present its identity that will be verified by its peer (the destination kube-apiserver). The destination API server verifies that peer connection based on the configuration you specify using the --requestheader-client-ca-file command line argument.To authenticate the destination server's serving certs, you must configure a certificate authority bundle by specifying the --peer-ca-file command line argument to the source API server.Configuration for peer API server connectivityTo set the network location of a kube-apiserver that peers will use to proxy requests, use the --peer-advertise-ip and --peer-advertise-port command line arguments to kube-apiserver or specify these fields in the API server configuration file. If these flags are unspecified, peers will use the value from either --advertise-address or --bind-address command line argument to the kube-apiserver. If those too, are unset, the host's default interface is used.Mixed version proxyingWhen you enable mixed version proxying, the aggregation layer loads a special filter that does the following:When a resource request reaches an API server that cannot serve that API (either because it is


Question: When would you use Mixed Version Proxy?

Answer: Mixed Version ProxyFEATURE STATE: Kubernetes v1.28 [alpha] (enabled by default: false)Kubernetes 1.34 includes an alpha feature that lets an API Server proxy a resource requests to other peer API servers. This is useful when there are multiple API servers running different versions of Kubernetes in one cluster (for example, during a long-lived rollout to a new release of Kubernetes).This enables cluster administrators to configure highly available clusters that can be upgraded more safely, by directing resource requests (made during the upgrade) to the correct kube-apiserver. That proxying prevents users from seeing unexpected 404 Not Found errors that stem from the upgrade process.This mechanism is called the Mixed Version Proxy.Enabling the Mixed Version ProxyEnsure that UnknownVersionInteroperabilityProxy feature gate is enabled when you start the API Server:kube-apiserver \ --feature-gates=UnknownVersionInteroperabilityProxy=true \ # required command line arguments for this feature --peer-ca-file=<path to kube-apiserver CA cert> --proxy-client-cert-file=<path to aggregator proxy cert>, --proxy-client-key-file=<path to aggregator proxy key>, --requestheader-client-ca-file=<path to aggregator CA cert>, # requestheader-allowed-names can be set to blank to allow any Common Name --requestheader-allowed-names=<valid Common Names to verify proxy client cert against>, # optional flags for this feature --peer-advertise-ip=`IP of this kube-apiserver that should be used by peers to proxy requests` --peer-advertise-port=`port of this kube-apiserver that should be used by peers to proxy requests` # …and other flags as usual Proxy transport and authentication between API serversThe source kube-apiserver reuses the existing APIserver client authentication flags --proxy-client-cert-file and --proxy-client-key-file to present its identity that will be verified by its peer (the destination kube-apiserver). The destination API server verifies that peer connection based on the configuration you specify using the --requestheader-client-ca-file command line argument.To authenticate the destination server's serving certs, you must configure a certificate authority bundle by specifying the --peer-ca-file command line argument to the source API server.Configuration for peer API server connectivityTo set the network location of a kube-apiserver that peers will use to proxy requests, use the --peer-advertise-ip and --peer-advertise-port command line arguments to kube-apiserver or specify these fields in the API server configuration file. If these flags are unspecified, peers will use the value from either --advertise-address or --bind-address command line argument to the kube-apiserver. If those too, are unset, the host's default interface is used.Mixed version proxyingWhen you enable mixed version proxying, the aggregation layer loads a special filter that does the following:When a resource request reaches an API server that cannot serve that API (either because it is


Question: What are the benefits of Mixed Version Proxy?

Answer: Mixed Version ProxyFEATURE STATE: Kubernetes v1.28 [alpha] (enabled by default: false)Kubernetes 1.34 includes an alpha feature that lets an API Server proxy a resource requests to other peer API servers. This is useful when there are multiple API servers running different versions of Kubernetes in one cluster (for example, during a long-lived rollout to a new release of Kubernetes).This enables cluster administrators to configure highly available clusters that can be upgraded more safely, by directing resource requests (made during the upgrade) to the correct kube-apiserver. That proxying prevents users from seeing unexpected 404 Not Found errors that stem from the upgrade process.This mechanism is called the Mixed Version Proxy.Enabling the Mixed Version ProxyEnsure that UnknownVersionInteroperabilityProxy feature gate is enabled when you start the API Server:kube-apiserver \ --feature-gates=UnknownVersionInteroperabilityProxy=true \ # required command line arguments for this feature --peer-ca-file=<path to kube-apiserver CA cert> --proxy-client-cert-file=<path to aggregator proxy cert>, --proxy-client-key-file=<path to aggregator proxy key>, --requestheader-client-ca-file=<path to aggregator CA cert>, # requestheader-allowed-names can be set to blank to allow any Common Name --requestheader-allowed-names=<valid Common Names to verify proxy client cert against>, # optional flags for this feature --peer-advertise-ip=`IP of this kube-apiserver that should be used by peers to proxy requests` --peer-advertise-port=`port of this kube-apiserver that should be used by peers to proxy requests` # …and other flags as usual Proxy transport and authentication between API serversThe source kube-apiserver reuses the existing APIserver client authentication flags --proxy-client-cert-file and --proxy-client-key-file to present its identity that will be verified by its peer (the destination kube-apiserver). The destination API server verifies that peer connection based on the configuration you specify using the --requestheader-client-ca-file command line argument.To authenticate the destination server's serving certs, you must configure a certificate authority bundle by specifying the --peer-ca-file command line argument to the source API server.Configuration for peer API server connectivityTo set the network location of a kube-apiserver that peers will use to proxy requests, use the --peer-advertise-ip and --peer-advertise-port command line arguments to kube-apiserver or specify these fields in the API server configuration file. If these flags are unspecified, peers will use the value from either --advertise-address or --bind-address command line argument to the kube-apiserver. If those too, are unset, the host's default interface is used.Mixed version proxyingWhen you enable mixed version proxying, the aggregation layer loads a special filter that does the following:When a resource request reaches an API server that cannot serve that API (either because it is


Question: What is Mixed Version Proxy?

Answer: K u b e r n e t e s   1 . 3 4   i n c l u d e s   a n   a l p h a   f e a t u r e   t h a t   l e t s   a n   A P I   S e r v e r   p r o x y   a   r e s o u r c e   r e q u e s t s   t o   o t h e r   p e e r   A P I   s e r v e r s .   T h i s   i s   u s e f u l   w h e n   t h e r e   a r e   m u l t i p l e   A P I   s e r v e r s   r u n n i n g   d i f f e r e n t   v e r s i o n s   o f   K u b e r n e t e s   i n   o n e   c l u s t e r   ( f o r   e x a m p l e ,   d u r i n g   a   l o n g - l i v e d   r o l l o u t   t o   a   n e w   r e l e a s e   o f   K u b e r n e t e s ) .   T h i s   e n a b l e s   c l u s t e r   a d m i n i s t r a t o r s   t o   c o n f i g u r e   h i g h l y   a v a i l a b l e   c l u s t e r s   t h a t   c a n   b e   u p g r a d e d   m o r e   s a f e l y ,   b y   d i r e c t i n g   r e s o u r c e   r e q u e s t s   ( m a d e   d u r i n g   t h e   u p g r a d e )   t o   t h e   c o r r e c t   k u b e - a p i s e r v e r .   T h a t   p r o x y i n g   p r e v e n t s   u s e r s   f r o m   s e e i n g   u n e x p e c t e d   4 0 4   N o t   F o u n d   e r r o r s   t h a t   s t e m   f r o m   t h e   u p g r a d e   p r o c e s s .   T h i s   m e c h a n i s m   i s   c a l l e d   t h e   M i x e d   V e r s i o n   P r o x y .


Question: What is Enabling the Mixed Version Proxy?

Answer: E n s u r e   t h a t   U n k n o w n V e r s i o n I n t e r o p e r a b i l i t y P r o x y   f e a t u r e   g a t e   i s   e n a b l e d   w h e n   y o u   s t a r t   t h e   A P I   S e r v e r :   k u b e - a p i s e r v e r   \   - - f e a t u r e - g a t e s = U n k n o w n V e r s i o n I n t e r o p e r a b i l i t y P r o x y = t r u e   \   #   r e q u i r e d   c o m m a n d   l i n e   a r g u m e n t s   f o r   t h i s   f e a t u r e   - - p e e r - c a - f i l e = < p a t h   t o   k u b e - a p i s e r v e r   C A   c e r t >   - - p r o x y - c l i e n t - c e r t - f i l e = < p a t h   t o   a g g r e g a t o r   p r o x y   c e r t > ,   - - p r o x y - c l i e n t - k e y - f i l e = < p a t h   t o   a g g r e g a t o r   p r o x y   k e y > ,   - - r e q u e s t h e a d e r - c l i e n t - c a - f i l e = < p a t h   t o   a g g r e g a t o r   C A   c e r t > ,   #   r e q u e s t h e a d e r - a l l o w e d - n a m e s   c a n   b e   s e t   t o   b l a n k   t o   a l l o w   a n y   C o m m o n   N a m e   - - r e q u e s t h e a d e r - a l l o w e d - n a m e s = < v a l i d   C o m m o n   N a m e s   t o   v e r i f y   p r o x y   c l i e n t   c e r t   a g a i n s t > ,   #   o p t i o n a l   f l a g s   f o r   t h i s   f e a t u r e   - - p e e r - a d v e r t i s e - i p = ` I P   o f   t h i s   k u b e - a p i s e r v e r   t h a t   s h o u l d   b e   u s e d   b y   p e e r s   t o   p r o x y   r e q u e s t s `   - - p e e r - a d v e r t i s e - p o r t = ` p o r t   o f   t h i s   k u b e - a p i s e r v e r   t h a t   s h o u l d   b e   u s e d   b y   p e e r s   t o   p r o x y   r e q u e s t s `   #   … a n d   o t h e r   f l a g s   a s   u s u a l


Question: What is Proxy transport and authentication between API servers?

Answer: T h e   s o u r c e   k u b e - a p i s e r v e r   r e u s e s   t h e   e x i s t i n g   A P I s e r v e r   c l i e n t   a u t h e n t i c a t i o n   f l a g s   - - p r o x y - c l i e n t - c e r t - f i l e   a n d   - - p r o x y - c l i e n t - k e y - f i l e   t o   p r e s e n t   i t s   i d e n t i t y   t h a t   w i l l   b e   v e r i f i e d   b y   i t s   p e e r   ( t h e   d e s t i n a t i o n   k u b e - a p i s e r v e r ) .   T h e   d e s t i n a t i o n   A P I   s e r v e r   v e r i f i e s   t h a t   p e e r   c o n n e c t i o n   b a s e d   o n   t h e   c o n f i g u r a t i o n   y o u   s p e c i f y   u s i n g   t h e   - - r e q u e s t h e a d e r - c l i e n t - c a - f i l e   c o m m a n d   l i n e   a r g u m e n t . T o   a u t h e n t i c a t e   t h e   d e s t i n a t i o n   s e r v e r ' s   s e r v i n g   c e r t s ,   y o u   m u s t   c o n f i g u r e   a   c e r t i f i c a t e   a u t h o r i t y   b u n d l e   b y   s p e c i f y i n g   t h e   - - p e e r - c a - f i l e   c o m m a n d   l i n e   a r g u m e n t   t o   t h e   s o u r c e   A P I   s e r v e r .   T h e   s o u r c e   k u b e - a p i s e r v e r   r e u s e s   t h e   e x i s t i n g   A P I s e r v e r   c l i e n t   a u t h e n t i c a t i o n   f l a g s   - - p r o x y - c l i e n t - c e r t - f i l e   a n d   - - p r o x y - c l i e n t - k e y - f i l e   t o   p r e s e n t   i t s   i d e n t i t y   t h a t   w i l l   b e   v e r i f i e d   b y   i t s   p e e r   ( t h e   d e s t i n a t i o n   k u b e - a p i s e r v e r ) .   T h e   d e s t i n a t i o n   A P I   s e r v e r   v e r i f i e s   t h a t   p e e r   c o n n e c t i o n   b a s e d   o n   t h e   c o n f i g u r a t i o n   y o u   s p e c i f y   u s i n g   t h e   - - r e q u e s t h e a d e r - c l i e n t - c a - f i l e   c o m m a n d   l i n e   a r g u m e n t .   T o   a u t h e n t i c a t e   t h e   d e s t i n a t i o n   s e r v


Question: What is Configuration for peer API server connectivity?

Answer: T o   s e t   t h e   n e t w o r k   l o c a t i o n   o f   a   k u b e - a p i s e r v e r   t h a t   p e e r s   w i l l   u s e   t o   p r o x y   r e q u e s t s ,   u s e   t h e   - - p e e r - a d v e r t i s e - i p   a n d   - - p e e r - a d v e r t i s e - p o r t   c o m m a n d   l i n e   a r g u m e n t s   t o   k u b e - a p i s e r v e r   o r   s p e c i f y   t h e s e   f i e l d s   i n   t h e   A P I   s e r v e r   c o n f i g u r a t i o n   f i l e .   I f   t h e s e   f l a g s   a r e   u n s p e c i f i e d ,   p e e r s   w i l l   u s e   t h e   v a l u e   f r o m   e i t h e r   - - a d v e r t i s e - a d d r e s s   o r   - - b i n d - a d d r e s s   c o m m a n d   l i n e   a r g u m e n t   t o   t h e   k u b e - a p i s e r v e r .   I f   t h o s e   t o o ,   a r e   u n s e t ,   t h e   h o s t ' s   d e f a u l t   i n t e r f a c e   i s   u s e d .


Question: What is Mixed version proxying?

Answer: W h e n   y o u   e n a b l e   m i x e d   v e r s i o n   p r o x y i n g ,   t h e   a g g r e g a t i o n   l a y e r   l o a d s   a   s p e c i a l   f i l t e r   t h a t   d o e s   t h e   f o l l o w i n g :   W h e n   a   r e s o u r c e   r e q u e s t   r e a c h e s   a n   A P I   s e r v e r   t h a t   c a n n o t   s e r v e   t h a t   A P I   ( e i t h e r   b e c a u s e   i t   i s   a t   a   v e r s i o n   p r e - d a t i n g   t h e   i n t r o d u c t i o n   o f   t h e   A P I   o r   t h e   A P I   i s   t u r n e d   o f f   o n   t h e   A P I   s e r v e r )   t h e   A P I   s e r v e r   a t t e m p t s   t o   s e n d   t h e   r e q u e s t   t o   a   p e e r   A P I   s e r v e r   t h a t   c a n   s e r v e   t h e   r e q u e s t e d   A P I .   I t   d o e s   s o   b y   i d e n t i f y i n g   A P I   g r o u p s   /   v e r s i o n s   /   r e s o u r c e s   t h a t   t h e   l o c a l   s e r v e r   d o e s n ' t   r e c o g n i s e ,   a n d   t r i e s   t o   p r o x y   t h o s e   r e q u e s t s   t o   a   p e e r   A P I   s e r v e r   t h a t   i s   c a p a b l e   o f   h a n d l i n g   t h e   r e q u e s t . I f   t h e   p e e r   A P I   s e r v e r   f a i l s   t o   r e s p o n d ,   t h e   s o u r c e   A P I   s e r v e r   r e s p o n d s   w i t h   5 0 3   ( " S e r v i c e   U n a v a i l a b l e " )   e r r o r .


Question: What is How it works under the hood?

Answer: W h e n   a n   A P I   S e r v e r   r e c e i v e s   a   r e s o u r c e   r e q u e s t ,   i t   f i r s t   c h e c k s   w h i c h   A P I   s e r v e r s   c a n   s e r v e   t h e   r e q u e s t e d   r e s o u r c e .   T h i s   c h e c k   h a p p e n s   u s i n g   t h e   i n t e r n a l   S t o r a g e V e r s i o n   A P I .   I f   t h e   r e s o u r c e   i s   k n o w n   t o   t h e   A P I   s e r v e r   t h a t   r e c e i v e d   t h e   r e q u e s t   ( f o r   e x a m p l e ,   G E T   / a p i / v 1 / p o d s / s o m e - p o d ) ,   t h e   r e q u e s t   i s   h a n d l e d   l o c a l l y . I f   t h e r e   i s   n o   i n t e r n a l   S t o r a g e V e r s i o n   o b j e c t   f o u n d   f o r   t h e   r e q u e s t e d   r e s o u r c e   ( f o r   e x a m p l e ,   G E T   / m y - a p i / v 1 / m y - r e s o u r c e )   a n d   t h e   c o n f i g u r e d   A P I S e r v i c e   s p e c i f i e s   p r o x y i n g   t o   a n   e x t e n s i o n   A P I   s e r v e r ,   t h a t   p r o x y i n g   h a p p e n s   f o l l o w i n g   t h e   u s u a l   f l o w   f o r   e x t e n s i o n   A P I s . I f   a   v a l i d   i n t e r n a l   S t o r a g e V e r s i o n   o b j e c t   i s   f o u n d   f o r   t h e   r e q u e s t e d   r e s o u r c e   ( f o r   e x a m p l e ,   G E T   / b a t c h / v 1 / j o b s )   a n d   t h e   A P I   s e r v e r   t r y i n g   t o   h a n d l e   t h e   r e q u e s t   ( t h e   h a n d l i n g   A P I   s e r v e r )   h a s   t h e   b a t c h   A P I   d i s a b l e d ,   t h e n   t h e   h a n d l i n g   A P I   s e r v e r   f e t c h e s   t h e   p e e r   A P I   s e r v e r s   t h a t   d o   s e r v e   t h e   r e l e v a n t   A P I   g r o u p   /   v e r s i o n   /   r e s o u r c e   ( a p i / v 1 / b a t c h   i n   t h i s   c a s e )   u s i n g   t h e   i n f o r m a t i o n   i n   t h e   f e t c h e d   S t o r a g e V e r s i o n   o b j e c t .   T h


Question: What is Debugging DNS Resolution?

Answer: Debugging DNS ResolutionThis page provides hints on diagnosing DNS problems.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour cluster must be configured to use the CoreDNS addon or its precursor, kube-dns.Your Kubernetes server must be at or later than version v1.6.To check the version, enter kubectl version.Create a simple Pod to use as a test environmentadmin/dns/dnsutils.yaml apiVersion: v1 kind: Pod metadata: name: dnsutils namespace: default spec: containers: - name: dnsutils image: registry.k8s.io/e2e-test-images/agnhost:2.39 imagePullPolicy: IfNotPresent restartPolicy: Always Note:This example creates a pod in the default namespace. DNS name resolution for services depends on the namespace of the pod. For more information, review DNS for Services and Pods.Use that manifest to create a Pod:kubectl apply -f https://k8s.io/examples/admin/dns/dnsutils.yaml pod/dnsutils created …and verify its status:kubectl get pods dnsutils NAME READY STATUS RESTARTS AGE dnsutils 1/1 Running 0 <some-time> Once that Pod is running, you can exec nslookup in that environment. If you see something like the following, DNS is working correctly.kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 Name: kubernetes.default Address 1: 10.0.0.1 If the nslookup command fails, check the following:Check the local DNS configuration firstTake a look inside the resolv.conf file. (See Customizing DNS Service and Known issues below for more information)kubectl exec -ti dnsutils -- cat /etc/resolv.conf Verify that the search path and name server are set up like the following (note that search path may vary for different cloud providers):search default.svc.cluster.local svc.cluster.local cluster.local google.internal c.gce_project_id.internal nameserver 10.0.0.10 options ndots:5 Errors such as the following indicate a problem with the CoreDNS (or kube-dns) add-on or with associated Services:kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 nslookup: can't resolve 'kubernetes.default' orkubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 kube-dns.kube-system.svc.cluster.local nslookup: can't resolve 'kubernetes.default' Check if the DNS pod is runningUse the kubectl get pods command to verify that the DNS pod is running.kubectl get pods --namespace=kube-system -l k8s-app=kube-dns NAME READY STATUS RESTARTS AGE ... coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h ... Note:The value for label k8s-app is kube-dns for both Core


Question: How does Debugging DNS Resolution work?

Answer: Debugging DNS ResolutionThis page provides hints on diagnosing DNS problems.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour cluster must be configured to use the CoreDNS addon or its precursor, kube-dns.Your Kubernetes server must be at or later than version v1.6.To check the version, enter kubectl version.Create a simple Pod to use as a test environmentadmin/dns/dnsutils.yaml apiVersion: v1 kind: Pod metadata: name: dnsutils namespace: default spec: containers: - name: dnsutils image: registry.k8s.io/e2e-test-images/agnhost:2.39 imagePullPolicy: IfNotPresent restartPolicy: Always Note:This example creates a pod in the default namespace. DNS name resolution for services depends on the namespace of the pod. For more information, review DNS for Services and Pods.Use that manifest to create a Pod:kubectl apply -f https://k8s.io/examples/admin/dns/dnsutils.yaml pod/dnsutils created …and verify its status:kubectl get pods dnsutils NAME READY STATUS RESTARTS AGE dnsutils 1/1 Running 0 <some-time> Once that Pod is running, you can exec nslookup in that environment. If you see something like the following, DNS is working correctly.kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 Name: kubernetes.default Address 1: 10.0.0.1 If the nslookup command fails, check the following:Check the local DNS configuration firstTake a look inside the resolv.conf file. (See Customizing DNS Service and Known issues below for more information)kubectl exec -ti dnsutils -- cat /etc/resolv.conf Verify that the search path and name server are set up like the following (note that search path may vary for different cloud providers):search default.svc.cluster.local svc.cluster.local cluster.local google.internal c.gce_project_id.internal nameserver 10.0.0.10 options ndots:5 Errors such as the following indicate a problem with the CoreDNS (or kube-dns) add-on or with associated Services:kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 nslookup: can't resolve 'kubernetes.default' orkubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 kube-dns.kube-system.svc.cluster.local nslookup: can't resolve 'kubernetes.default' Check if the DNS pod is runningUse the kubectl get pods command to verify that the DNS pod is running.kubectl get pods --namespace=kube-system -l k8s-app=kube-dns NAME READY STATUS RESTARTS AGE ... coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h ... Note:The value for label k8s-app is kube-dns for both Core


Question: When would you use Debugging DNS Resolution?

Answer: Debugging DNS ResolutionThis page provides hints on diagnosing DNS problems.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour cluster must be configured to use the CoreDNS addon or its precursor, kube-dns.Your Kubernetes server must be at or later than version v1.6.To check the version, enter kubectl version.Create a simple Pod to use as a test environmentadmin/dns/dnsutils.yaml apiVersion: v1 kind: Pod metadata: name: dnsutils namespace: default spec: containers: - name: dnsutils image: registry.k8s.io/e2e-test-images/agnhost:2.39 imagePullPolicy: IfNotPresent restartPolicy: Always Note:This example creates a pod in the default namespace. DNS name resolution for services depends on the namespace of the pod. For more information, review DNS for Services and Pods.Use that manifest to create a Pod:kubectl apply -f https://k8s.io/examples/admin/dns/dnsutils.yaml pod/dnsutils created …and verify its status:kubectl get pods dnsutils NAME READY STATUS RESTARTS AGE dnsutils 1/1 Running 0 <some-time> Once that Pod is running, you can exec nslookup in that environment. If you see something like the following, DNS is working correctly.kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 Name: kubernetes.default Address 1: 10.0.0.1 If the nslookup command fails, check the following:Check the local DNS configuration firstTake a look inside the resolv.conf file. (See Customizing DNS Service and Known issues below for more information)kubectl exec -ti dnsutils -- cat /etc/resolv.conf Verify that the search path and name server are set up like the following (note that search path may vary for different cloud providers):search default.svc.cluster.local svc.cluster.local cluster.local google.internal c.gce_project_id.internal nameserver 10.0.0.10 options ndots:5 Errors such as the following indicate a problem with the CoreDNS (or kube-dns) add-on or with associated Services:kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 nslookup: can't resolve 'kubernetes.default' orkubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 kube-dns.kube-system.svc.cluster.local nslookup: can't resolve 'kubernetes.default' Check if the DNS pod is runningUse the kubectl get pods command to verify that the DNS pod is running.kubectl get pods --namespace=kube-system -l k8s-app=kube-dns NAME READY STATUS RESTARTS AGE ... coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h ... Note:The value for label k8s-app is kube-dns for both Core


Question: What are the benefits of Debugging DNS Resolution?

Answer: Debugging DNS ResolutionThis page provides hints on diagnosing DNS problems.Before you beginYou need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour cluster must be configured to use the CoreDNS addon or its precursor, kube-dns.Your Kubernetes server must be at or later than version v1.6.To check the version, enter kubectl version.Create a simple Pod to use as a test environmentadmin/dns/dnsutils.yaml apiVersion: v1 kind: Pod metadata: name: dnsutils namespace: default spec: containers: - name: dnsutils image: registry.k8s.io/e2e-test-images/agnhost:2.39 imagePullPolicy: IfNotPresent restartPolicy: Always Note:This example creates a pod in the default namespace. DNS name resolution for services depends on the namespace of the pod. For more information, review DNS for Services and Pods.Use that manifest to create a Pod:kubectl apply -f https://k8s.io/examples/admin/dns/dnsutils.yaml pod/dnsutils created …and verify its status:kubectl get pods dnsutils NAME READY STATUS RESTARTS AGE dnsutils 1/1 Running 0 <some-time> Once that Pod is running, you can exec nslookup in that environment. If you see something like the following, DNS is working correctly.kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 Name: kubernetes.default Address 1: 10.0.0.1 If the nslookup command fails, check the following:Check the local DNS configuration firstTake a look inside the resolv.conf file. (See Customizing DNS Service and Known issues below for more information)kubectl exec -ti dnsutils -- cat /etc/resolv.conf Verify that the search path and name server are set up like the following (note that search path may vary for different cloud providers):search default.svc.cluster.local svc.cluster.local cluster.local google.internal c.gce_project_id.internal nameserver 10.0.0.10 options ndots:5 Errors such as the following indicate a problem with the CoreDNS (or kube-dns) add-on or with associated Services:kubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 nslookup: can't resolve 'kubernetes.default' orkubectl exec -i -t dnsutils -- nslookup kubernetes.default Server: 10.0.0.10 Address 1: 10.0.0.10 kube-dns.kube-system.svc.cluster.local nslookup: can't resolve 'kubernetes.default' Check if the DNS pod is runningUse the kubectl get pods command to verify that the DNS pod is running.kubectl get pods --namespace=kube-system -l k8s-app=kube-dns NAME READY STATUS RESTARTS AGE ... coredns-7b96bf9f76-5hsxb 1/1 Running 0 1h coredns-7b96bf9f76-mvmmt 1/1 Running 0 1h ... Note:The value for label k8s-app is kube-dns for both Core


Question: What is Debugging DNS Resolution?

Answer: T h i s   p a g e   p r o v i d e s   h i n t s   o n   d i a g n o s i n g   D N S   p r o b l e m s .