Question: What is Configure a kubelet image credential provider?

Answer: S t a r t i n g   f r o m   K u b e r n e t e s   v 1 . 2 0 ,   t h e   k u b e l e t   c a n   d y n a m i c a l l y   r e t r i e v e   c r e d e n t i a l s   f o r   a   c o n t a i n e r   i m a g e   r e g i s t r y   u s i n g   e x e c   p l u g i n s .   T h e   k u b e l e t   a n d   t h e   e x e c   p l u g i n   c o m m u n i c a t e   t h r o u g h   s t d i o   ( s t d i n ,   s t d o u t ,   a n d   s t d e r r )   u s i n g   K u b e r n e t e s   v e r s i o n e d   A P I s .   T h e s e   p l u g i n s   a l l o w   t h e   k u b e l e t   t o   r e q u e s t   c r e d e n t i a l s   f o r   a   c o n t a i n e r   r e g i s t r y   d y n a m i c a l l y   a s   o p p o s e d   t o   s t o r i n g   s t a t i c   c r e d e n t i a l s   o n   d i s k .   F o r   e x a m p l e ,   t h e   p l u g i n   m a y   t a l k   t o   a   l o c a l   m e t a d a t a   s e r v e r   t o   r e t r i e v e   s h o r t - l i v e d   c r e d e n t i a l s   f o r   a n   i m a g e   t h a t   i s   b e i n g   p u l l e d   b y   t h e   k u b e l e t .   Y o u   m a y   b e   i n t e r e s t e d   i n   u s i n g   t h i s   c a p a b i l i t y   i f   a n y   o f   t h e   b e l o w   a r e   t r u e :   A P I   c a l l s   t o   a   c l o u d   p r o v i d e r   s e r v i c e   a r e   r e q u i r e d   t o   r e t r i e v e   a u t h e n t i c a t i o n   i n f o r m a t i o n   f o r   a   r e g i s t r y . C r e d e n t i a l s   h a v e   s h o r t   e x p i r a t i o n   t i m e s   a n d   r e q u e s t i n g   n e w   c r e d e n t i a l s   f r e q u e n t l y   i s   r e q u i r e d . S t o r i n g   r e g i s t r y   c r e d e n t i a l s   o n   d i s k   o r   i n   i m a g e P u l l S e c r e t s   i s   n o t   a c c e p t a b l e .   T h i s   g u i d e   d e m o n s t r a t e s   h o w   t o   c o n f i g u r e   t h e   k u b e l e t ' s   i m a g e   c r e d e n t i a l   p r o v i d e r   p l u g i n   m e c h a n i s m .


Question: What is Service Account Token for Image Pulls?

Answer: S t a r t i n g   f r o m   K u b e r n e t e s   v 1 . 3 3 ,   t h e   k u b e l e t   c a n   b e   c o n f i g u r e d   t o   s e n d   a   s e r v i c e   a c c o u n t   t o k e n   b o u n d   t o   t h e   p o d   f o r   w h i c h   t h e   i m a g e   p u l l   i s   b e i n g   p e r f o r m e d   t o   t h e   c r e d e n t i a l   p r o v i d e r   p l u g i n .   T h i s   a l l o w s   t h e   p l u g i n   t o   e x c h a n g e   t h e   t o k e n   f o r   c r e d e n t i a l s   t o   a c c e s s   t h e   i m a g e   r e g i s t r y .   T o   e n a b l e   t h i s   f e a t u r e ,   t h e   K u b e l e t S e r v i c e A c c o u n t T o k e n F o r C r e d e n t i a l P r o v i d e r s   f e a t u r e   g a t e   m u s t   b e   e n a b l e d   o n   t h e   k u b e l e t ,   a n d   t h e   t o k e n A t t r i b u t e s   f i e l d   m u s t   b e   s e t   i n   t h e   C r e d e n t i a l P r o v i d e r C o n f i g   f i l e   f o r   t h e   p l u g i n .   T h e   t o k e n A t t r i b u t e s   f i e l d   c o n t a i n s   i n f o r m a t i o n   a b o u t   t h e   s e r v i c e   a c c o u n t   t o k e n   t h a t   w i l l   b e   p a s s e d   t o   t h e   p l u g i n ,   i n c l u d i n g   t h e   i n t e n d e d   a u d i e n c e   f o r   t h e   t o k e n   a n d   w h e t h e r   t h e   p l u g i n   r e q u i r e s   t h e   p o d   t o   h a v e   a   s e r v i c e   a c c o u n t .   U s i n g   s e r v i c e   a c c o u n t   t o k e n   c r e d e n t i a l s   c a n   e n a b l e   t h e   f o l l o w i n g   u s e - c a s e s :   A v o i d   n e e d i n g   a   k u b e l e t / n o d e - b a s e d   i d e n t i t y   t o   p u l l   i m a g e s   f r o m   a   r e g i s t r y . A l l o w   w o r k l o a d s   t o   p u l l   i m a g e s   b a s e d   o n   t h e i r   o w n   r u n t i m e   i d e n t i t y   w i t h o u t   l o n g - l i v e d / p e r s i s t e d   s e c r e t s .


Question: What is Before you begin?

Answer: Y o u   n e e d   a   K u b e r n e t e s   c l u s t e r   w i t h   n o d e s   t h a t   s u p p o r t   k u b e l e t   c r e d e n t i a l   p r o v i d e r   p l u g i n s .   T h i s   s u p p o r t   i s   a v a i l a b l e   i n   K u b e r n e t e s   1 . 3 4 ;   K u b e r n e t e s   v 1 . 2 4   a n d   v 1 . 2 5   i n c l u d e d   t h i s   a s   a   b e t a   f e a t u r e ,   e n a b l e d   b y   d e f a u l t . I f   y o u   a r e   c o n f i g u r i n g   a   c r e d e n t i a l   p r o v i d e r   p l u g i n   t h a t   r e q u i r e s   t h e   s e r v i c e   a c c o u n t   t o k e n ,   y o u   n e e d   a   K u b e r n e t e s   c l u s t e r   w i t h   n o d e s   r u n n i n g   K u b e r n e t e s   v 1 . 3 3   o r   l a t e r   a n d   t h e   K u b e l e t S e r v i c e A c c o u n t T o k e n F o r C r e d e n t i a l P r o v i d e r s   f e a t u r e   g a t e   e n a b l e d   o n   t h e   k u b e l e t . A   w o r k i n g   i m p l e m e n t a t i o n   o f   a   c r e d e n t i a l   p r o v i d e r   e x e c   p l u g i n .   Y o u   c a n   b u i l d   y o u r   o w n   p l u g i n   o r   u s e   o n e   p r o v i d e d   b y   c l o u d   p r o v i d e r s .   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 Installing Plugins on Nodes?

Answer: A   c r e d e n t i a l   p r o v i d e r   p l u g i n   i s   a n   e x e c u t a b l e   b i n a r y   t h a t   w i l l   b e   r u n   b y   t h e   k u b e l e t .   E n s u r e   t h a t   t h e   p l u g i n   b i n a r y   e x i s t s   o n   e v e r y   n o d e   i n   y o u r   c l u s t e r   a n d   s t o r e d   i n   a   k n o w n   d i r e c t o r y .   T h e   d i r e c t o r y   w i l l   b e   r e q u i r e d   l a t e r   w h e n   c o n f i g u r i n g   k u b e l e t   f l a g s .


Question: What is Configuring the Kubelet?

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


Question: What is Configure a kubelet credential provider?

Answer: T h e   c o n f i g u r a t i o n   f i l e   p a s s e d   i n t o   - - i m a g e - c r e d e n t i a l - p r o v i d e r - c o n f i g   i s   r e a d   b y   t h e   k u b e l e t   t o   d e t e r m i n e   w h i c h   e x e c   p l u g i n s   s h o u l d   b e   i n v o k e d   f o r   w h i c h   c o n t a i n e r   i m a g e s .   H e r e ' s   a n   e x a m p l e   c o n f i g u r a t i o n   f i l e   y o u   m a y   e n d   u p   u s i n g   i f   y o u   a r e   u s i n g   t h e   E C R - b a s e d   p l u g i n :   a p i V e r s i o n :   k u b e l e t . c o n f i g . k 8 s . i o / v 1   k i n d :   C r e d e n t i a l P r o v i d e r C o n f i g   #   p r o v i d e r s   i s   a   l i s t   o f   c r e d e n t i a l   p r o v i d e r   h e l p e r   p l u g i n s   t h a t   w i l l   b e   e n a b l e d   b y   t h e   k u b e l e t .   #   M u l t i p l e   p r o v i d e r s   m a y   m a t c h   a g a i n s t   a   s i n g l e   i m a g e ,   i n   w h i c h   c a s e   c r e d e n t i a l s   #   f r o m   a l l   p r o v i d e r s   w i l l   b e   r e t u r n e d   t o   t h e   k u b e l e t .   I f   m u l t i p l e   p r o v i d e r s   a r e   c a l l e d   #   f o r   a   s i n g l e   i m a g e ,   t h e   r e s u l t s   a r e   c o m b i n e d .   I f   p r o v i d e r s   r e t u r n   o v e r l a p p i n g   #   a u t h   k e y s ,   t h e   v a l u e   f r o m   t h e   p r o v i d e r   e a r l i e r   i n   t h i s   l i s t   i s   u s e d .   p r o v i d e r s :   #   n a m e   i s   t h e   r e q u i r e d   n a m e   o f   t h e   c r e d e n t i a l   p r o v i d e r .   I t   m u s t   m a t c h   t h e   n a m e   o f   t h e   #   p r o v i d e r   e x e c u t a b l e   a s   s e e n   b y   t h e   k u b e l e t .   T h e   e x e c u t a b l e   m u s t   b e   i n   t h e   k u b e l e t ' s   #   b i n   d i r e c t o r y   ( s e t   b y   t h e   - - i m a g e - c r e d e n t i a l - p r o v i d e r - b i n - d i r   f


Question: What is Configure image matching?

Answer: T h e   m a t c h I m a g e s   f i e l d   f o r   e a c h   c r e d e n t i a l   p r o v i d e r   i s   u s e d   b y   t h e   k u b e l e t   t o   d e t e r m i n e   w h e t h e r   a   p l u g i n   s h o u l d   b e   i n v o k e d   f o r   a   g i v e n   i m a g e   t h a t   a   P o d   i s   u s i n g .   E a c h   e n t r y   i n   m a t c h I m a g e s   i s   a n   i m a g e   p a t t e r n   w h i c h   c a n   o p t i o n a l l y   c o n t a i n   a   p o r t   a n d   a   p a t h .   G l o b s   c a n   b e   u s e d   i n   t h e   d o m a i n ,   b u t   n o t   i n   t h e   p o r t   o r   t h e   p a t h .   G l o b s   a r e   s u p p o r t e d   a s   s u b d o m a i n s   l i k e   * . k 8 s . i o   o r   k 8 s . * . i o ,   a n d   t o p - l e v e l   d o m a i n s   s u c h   a s   k 8 s . * .   M a t c h i n g   p a r t i a l   s u b d o m a i n s   l i k e   a p p * . k 8 s . i o   i s   a l s o   s u p p o r t e d .   E a c h   g l o b   c a n   o n l y   m a t c h   a   s i n g l e   s u b d o m a i n   s e g m e n t ,   s o   * . i o   d o e s   N O T   m a t c h   * . k 8 s . i o .   A   m a t c h   e x i s t s   b e t w e e n   a n   i m a g e   n a m e   a n d   a   m a t c h I m a g e   e n t r y   w h e n   a l l   o f   t h e   b e l o w   a r e   t r u e :   B o t h   c o n t a i n   t h e   s a m e   n u m b e r   o f   d o m a i n   p a r t s   a n d   e a c h   p a r t   m a t c h e s . T h e   U R L   p a t h   o f   m a t c h   i m a g e   m u s t   b e   a   p r e f i x   o f   t h e   t a r g e t   i m a g e   U R L   p a t h . I f   t h e   m a t c h I m a g e s   c o n t a i n s   a   p o r t ,   t h e n   t h e   p o r t   m u s t   m a t c h   i n   t h e   i m a g e   a s   w e l l .   S o m e   e x a m p l e   v a l u e s   o f   m a t c h I m a g e s   p a t t e r n s   a r e :   1 2 3 4 5 6 7 8 9 . d k r . e c r . u s - e a s t - 1 . a m a z o n a w s . c o m * . a z u r e c r . i o g c r . i o * . * . r e g


Question: What is What's next?

Answer: R e a d   t h e   d e t a i l s   a b o u t   C r e d e n t i a l P r o v i d e r C o n f i g   i n   t h e   k u b e l e t   c o n f i g u r a t i o n   A P I   ( v 1 )   r e f e r e n c e . R e a d   t h e   k u b e l e t   c r e d e n t i a l   p r o v i d e r   A P I   r e f e r e n c e   ( v 1 ) .


Question: What is Troubleshooting kubectl?

Answer: Troubleshooting kubectlThis documentation is about investigating and diagnosing kubectl related issues. If you encounter issues accessing kubectl or connecting to your cluster, this document outlines various common scenarios and potential solutions to help identify and address the likely cause.Before you beginYou need to have a Kubernetes cluster.You also need to have kubectl installed - see install toolsVerify kubectl setupMake sure you have installed and configured kubectl correctly on your local machine. Check the kubectl version to ensure it is up-to-date and compatible with your cluster.Check kubectl version:kubectl version You'll see a similar output:Client Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.4",GitCommit:"fa3d7990104d7c1f16943a67f11b154b71f6a132", GitTreeState:"clean",BuildDate:"2023-07-19T12:20:54Z", GoVersion:"go1.20.6", Compiler:"gc", Platform:"linux/amd64"} Kustomize Version: v5.0.1 Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.3",GitCommit:"25b4e43193bcda6c7328a6d147b1fb73a33f1598", GitTreeState:"clean",BuildDate:"2023-06-14T09:47:40Z", GoVersion:"go1.20.5", Compiler:"gc", Platform:"linux/amd64"} If you see Unable to connect to the server: dial tcp <server-ip>:8443: i/o timeout, instead of Server Version, you need to troubleshoot kubectl connectivity with your cluster.Make sure you have installed the kubectl by following the official documentation for installing kubectl, and you have properly configured the $PATH environment variable.Check kubeconfigThe kubectl requires a kubeconfig file to connect to a Kubernetes cluster. The kubeconfig file is usually located under the ~/.kube/config directory. Make sure that you have a valid kubeconfig file. If you don't have a kubeconfig file, you can obtain it from your Kubernetes administrator, or you can copy it from your Kubernetes control plane's /etc/kubernetes/admin.conf directory. If you have deployed your Kubernetes cluster on a cloud platform and lost your kubeconfig file, you can re-generate it using your cloud provider's tools. Refer the cloud provider's documentation for re-generating a kubeconfig file.Check if the $KUBECONFIG environment variable is configured correctly. You can set $KUBECONFIGenvironment variable or use the --kubeconfig parameter with the kubectl to specify the directory of a kubeconfig file.Check VPN connectivityIf you are using a Virtual Private Network (VPN) to access your Kubernetes cluster, make sure that your VPN connection is active and stable. Sometimes, VPN disconnections can lead to connection issues with the cluster. Reconnect to the VPN and try accessing the cluster again.Authentication and authorizationIf you are using the token based authentication and the kubectl is returning an error regarding the authentication token or authentication server address, validate the Kubernetes authentication token and the authentication server address are configured properly.If kubectl is returning an error regarding t


Question: How does Troubleshooting kubectl work?

Answer: Troubleshooting kubectlThis documentation is about investigating and diagnosing kubectl related issues. If you encounter issues accessing kubectl or connecting to your cluster, this document outlines various common scenarios and potential solutions to help identify and address the likely cause.Before you beginYou need to have a Kubernetes cluster.You also need to have kubectl installed - see install toolsVerify kubectl setupMake sure you have installed and configured kubectl correctly on your local machine. Check the kubectl version to ensure it is up-to-date and compatible with your cluster.Check kubectl version:kubectl version You'll see a similar output:Client Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.4",GitCommit:"fa3d7990104d7c1f16943a67f11b154b71f6a132", GitTreeState:"clean",BuildDate:"2023-07-19T12:20:54Z", GoVersion:"go1.20.6", Compiler:"gc", Platform:"linux/amd64"} Kustomize Version: v5.0.1 Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.3",GitCommit:"25b4e43193bcda6c7328a6d147b1fb73a33f1598", GitTreeState:"clean",BuildDate:"2023-06-14T09:47:40Z", GoVersion:"go1.20.5", Compiler:"gc", Platform:"linux/amd64"} If you see Unable to connect to the server: dial tcp <server-ip>:8443: i/o timeout, instead of Server Version, you need to troubleshoot kubectl connectivity with your cluster.Make sure you have installed the kubectl by following the official documentation for installing kubectl, and you have properly configured the $PATH environment variable.Check kubeconfigThe kubectl requires a kubeconfig file to connect to a Kubernetes cluster. The kubeconfig file is usually located under the ~/.kube/config directory. Make sure that you have a valid kubeconfig file. If you don't have a kubeconfig file, you can obtain it from your Kubernetes administrator, or you can copy it from your Kubernetes control plane's /etc/kubernetes/admin.conf directory. If you have deployed your Kubernetes cluster on a cloud platform and lost your kubeconfig file, you can re-generate it using your cloud provider's tools. Refer the cloud provider's documentation for re-generating a kubeconfig file.Check if the $KUBECONFIG environment variable is configured correctly. You can set $KUBECONFIGenvironment variable or use the --kubeconfig parameter with the kubectl to specify the directory of a kubeconfig file.Check VPN connectivityIf you are using a Virtual Private Network (VPN) to access your Kubernetes cluster, make sure that your VPN connection is active and stable. Sometimes, VPN disconnections can lead to connection issues with the cluster. Reconnect to the VPN and try accessing the cluster again.Authentication and authorizationIf you are using the token based authentication and the kubectl is returning an error regarding the authentication token or authentication server address, validate the Kubernetes authentication token and the authentication server address are configured properly.If kubectl is returning an error regarding t


Question: When would you use Troubleshooting kubectl?

Answer: Troubleshooting kubectlThis documentation is about investigating and diagnosing kubectl related issues. If you encounter issues accessing kubectl or connecting to your cluster, this document outlines various common scenarios and potential solutions to help identify and address the likely cause.Before you beginYou need to have a Kubernetes cluster.You also need to have kubectl installed - see install toolsVerify kubectl setupMake sure you have installed and configured kubectl correctly on your local machine. Check the kubectl version to ensure it is up-to-date and compatible with your cluster.Check kubectl version:kubectl version You'll see a similar output:Client Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.4",GitCommit:"fa3d7990104d7c1f16943a67f11b154b71f6a132", GitTreeState:"clean",BuildDate:"2023-07-19T12:20:54Z", GoVersion:"go1.20.6", Compiler:"gc", Platform:"linux/amd64"} Kustomize Version: v5.0.1 Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.3",GitCommit:"25b4e43193bcda6c7328a6d147b1fb73a33f1598", GitTreeState:"clean",BuildDate:"2023-06-14T09:47:40Z", GoVersion:"go1.20.5", Compiler:"gc", Platform:"linux/amd64"} If you see Unable to connect to the server: dial tcp <server-ip>:8443: i/o timeout, instead of Server Version, you need to troubleshoot kubectl connectivity with your cluster.Make sure you have installed the kubectl by following the official documentation for installing kubectl, and you have properly configured the $PATH environment variable.Check kubeconfigThe kubectl requires a kubeconfig file to connect to a Kubernetes cluster. The kubeconfig file is usually located under the ~/.kube/config directory. Make sure that you have a valid kubeconfig file. If you don't have a kubeconfig file, you can obtain it from your Kubernetes administrator, or you can copy it from your Kubernetes control plane's /etc/kubernetes/admin.conf directory. If you have deployed your Kubernetes cluster on a cloud platform and lost your kubeconfig file, you can re-generate it using your cloud provider's tools. Refer the cloud provider's documentation for re-generating a kubeconfig file.Check if the $KUBECONFIG environment variable is configured correctly. You can set $KUBECONFIGenvironment variable or use the --kubeconfig parameter with the kubectl to specify the directory of a kubeconfig file.Check VPN connectivityIf you are using a Virtual Private Network (VPN) to access your Kubernetes cluster, make sure that your VPN connection is active and stable. Sometimes, VPN disconnections can lead to connection issues with the cluster. Reconnect to the VPN and try accessing the cluster again.Authentication and authorizationIf you are using the token based authentication and the kubectl is returning an error regarding the authentication token or authentication server address, validate the Kubernetes authentication token and the authentication server address are configured properly.If kubectl is returning an error regarding t


Question: What are the benefits of Troubleshooting kubectl?

Answer: Troubleshooting kubectlThis documentation is about investigating and diagnosing kubectl related issues. If you encounter issues accessing kubectl or connecting to your cluster, this document outlines various common scenarios and potential solutions to help identify and address the likely cause.Before you beginYou need to have a Kubernetes cluster.You also need to have kubectl installed - see install toolsVerify kubectl setupMake sure you have installed and configured kubectl correctly on your local machine. Check the kubectl version to ensure it is up-to-date and compatible with your cluster.Check kubectl version:kubectl version You'll see a similar output:Client Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.4",GitCommit:"fa3d7990104d7c1f16943a67f11b154b71f6a132", GitTreeState:"clean",BuildDate:"2023-07-19T12:20:54Z", GoVersion:"go1.20.6", Compiler:"gc", Platform:"linux/amd64"} Kustomize Version: v5.0.1 Server Version: version.Info{Major:"1", Minor:"27", GitVersion:"v1.27.3",GitCommit:"25b4e43193bcda6c7328a6d147b1fb73a33f1598", GitTreeState:"clean",BuildDate:"2023-06-14T09:47:40Z", GoVersion:"go1.20.5", Compiler:"gc", Platform:"linux/amd64"} If you see Unable to connect to the server: dial tcp <server-ip>:8443: i/o timeout, instead of Server Version, you need to troubleshoot kubectl connectivity with your cluster.Make sure you have installed the kubectl by following the official documentation for installing kubectl, and you have properly configured the $PATH environment variable.Check kubeconfigThe kubectl requires a kubeconfig file to connect to a Kubernetes cluster. The kubeconfig file is usually located under the ~/.kube/config directory. Make sure that you have a valid kubeconfig file. If you don't have a kubeconfig file, you can obtain it from your Kubernetes administrator, or you can copy it from your Kubernetes control plane's /etc/kubernetes/admin.conf directory. If you have deployed your Kubernetes cluster on a cloud platform and lost your kubeconfig file, you can re-generate it using your cloud provider's tools. Refer the cloud provider's documentation for re-generating a kubeconfig file.Check if the $KUBECONFIG environment variable is configured correctly. You can set $KUBECONFIGenvironment variable or use the --kubeconfig parameter with the kubectl to specify the directory of a kubeconfig file.Check VPN connectivityIf you are using a Virtual Private Network (VPN) to access your Kubernetes cluster, make sure that your VPN connection is active and stable. Sometimes, VPN disconnections can lead to connection issues with the cluster. Reconnect to the VPN and try accessing the cluster again.Authentication and authorizationIf you are using the token based authentication and the kubectl is returning an error regarding the authentication token or authentication server address, validate the Kubernetes authentication token and the authentication server address are configured properly.If kubectl is returning an error regarding t


Question: What is Troubleshooting kubectl?

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


Question: What is Before you begin?

Answer: Y o u   n e e d   t o   h a v e   a   K u b e r n e t e s   c l u s t e r . Y o u   a l s o   n e e d   t o   h a v e   k u b e c t l   i n s t a l l e d   -   s e e   i n s t a l l   t o o l s


Question: What is Verify kubectl setup?

Answer: M a k e   s u r e   y o u   h a v e   i n s t a l l e d   a n d   c o n f i g u r e d   k u b e c t l   c o r r e c t l y   o n   y o u r   l o c a l   m a c h i n e .   C h e c k   t h e   k u b e c t l   v e r s i o n   t o   e n s u r e   i t   i s   u p - t o - d a t e   a n d   c o m p a t i b l e   w i t h   y o u r   c l u s t e r .   C h e c k   k u b e c t l   v e r s i o n :   k u b e c t l   v e r s i o n   Y o u ' l l   s e e   a   s i m i l a r   o u t p u t :   C l i e n t   V e r s i o n :   v e r s i o n . I n f o { M a j o r : " 1 " ,   M i n o r : " 2 7 " ,   G i t V e r s i o n : " v 1 . 2 7 . 4 " , G i t C o m m i t : " f a 3 d 7 9 9 0 1 0 4 d 7 c 1 f 1 6 9 4 3 a 6 7 f 1 1 b 1 5 4 b 7 1 f 6 a 1 3 2 " ,   G i t T r e e S t a t e : " c l e a n " , B u i l d D a t e : " 2 0 2 3 - 0 7 - 1 9 T 1 2 : 2 0 : 5 4 Z " ,   G o V e r s i o n : " g o 1 . 2 0 . 6 " ,   C o m p i l e r : " g c " ,   P l a t f o r m : " l i n u x / a m d 6 4 " }   K u s t o m i z e   V e r s i o n :   v 5 . 0 . 1   S e r v e r   V e r s i o n :   v e r s i o n . I n f o { M a j o r : " 1 " ,   M i n o r : " 2 7 " ,   G i t V e r s i o n : " v 1 . 2 7 . 3 " , G i t C o m m i t : " 2 5 b 4 e 4 3 1 9 3 b c d a 6 c 7 3 2 8 a 6 d 1 4 7 b 1 f b 7 3 a 3 3 f 1 5 9 8 " ,   G i t T r e e S t a t e : " c l e a n " , B u i l d D a t e : " 2 0 2 3 - 0 6 - 1 4 T 0 9 : 4 7 : 4 0 Z " ,   G o V e r s i o n : " g o 1 . 2 0 . 5 " ,   C o m p i l e r : " g c " ,   P l a t f o r m : " l i n u x / a m d 6 4 " }   I f   y o u   s e e   U n a b l e   t o   c o n n e c t   t o   t h e   s e r v e r :   d i a l   t c p   < s e r v e r - i p > : 8 4 4 3 :   i / o   t i m e o u t ,   i n s t e a d   o f   S e r v e r   V e r s i o n ,   y o u   n e e d   t o   t r o u b l e s h o o t   k u b e c t l   c o n n e c t i v i t y   w i t h   y o u r   c l u s t e r .   M a k e   s u r e   y o u   h a v e   i n s t a l l e d   t h e   k u b e c t l   b y   f o l l o w i n g   t h e   o f f i c i a l   d o c u m


Question: What is Check kubeconfig?

Answer: T h e   k u b e c t l   r e q u i r e s   a   k u b e c o n f i g   f i l e   t o   c o n n e c t   t o   a   K u b e r n e t e s   c l u s t e r .   T h e   k u b e c o n f i g   f i l e   i s   u s u a l l y   l o c a t e d   u n d e r   t h e   ~ / . k u b e / c o n f i g   d i r e c t o r y .   M a k e   s u r e   t h a t   y o u   h a v e   a   v a l i d   k u b e c o n f i g   f i l e .   I f   y o u   d o n ' t   h a v e   a   k u b e c o n f i g   f i l e ,   y o u   c a n   o b t a i n   i t   f r o m   y o u r   K u b e r n e t e s   a d m i n i s t r a t o r ,   o r   y o u   c a n   c o p y   i t   f r o m   y o u r   K u b e r n e t e s   c o n t r o l   p l a n e ' s   / e t c / k u b e r n e t e s / a d m i n . c o n f   d i r e c t o r y .   I f   y o u   h a v e   d e p l o y e d   y o u r   K u b e r n e t e s   c l u s t e r   o n   a   c l o u d   p l a t f o r m   a n d   l o s t   y o u r   k u b e c o n f i g   f i l e ,   y o u   c a n   r e - g e n e r a t e   i t   u s i n g   y o u r   c l o u d   p r o v i d e r ' s   t o o l s .   R e f e r   t h e   c l o u d   p r o v i d e r ' s   d o c u m e n t a t i o n   f o r   r e - g e n e r a t i n g   a   k u b e c o n f i g   f i l e .   C h e c k   i f   t h e   $ K U B E C O N F I G   e n v i r o n m e n t   v a r i a b l e   i s   c o n f i g u r e d   c o r r e c t l y .   Y o u   c a n   s e t   $ K U B E C O N F I G e n v i r o n m e n t   v a r i a b l e   o r   u s e   t h e   - - k u b e c o n f i g   p a r a m e t e r   w i t h   t h e   k u b e c t l   t o   s p e c i f y   t h e   d i r e c t o r y   o f   a   k u b e c o n f i g   f i l e .


Question: What is Check VPN connectivity?

Answer: I f   y o u   a r e   u s i n g   a   V i r t u a l   P r i v a t e   N e t w o r k   ( V P N )   t o   a c c e s s   y o u r   K u b e r n e t e s   c l u s t e r ,   m a k e   s u r e   t h a t   y o u r   V P N   c o n n e c t i o n   i s   a c t i v e   a n d   s t a b l e .   S o m e t i m e s ,   V P N   d i s c o n n e c t i o n s   c a n   l e a d   t o   c o n n e c t i o n   i s s u e s   w i t h   t h e   c l u s t e r .   R e c o n n e c t   t o   t h e   V P N   a n d   t r y   a c c e s s i n g   t h e   c l u s t e r   a g a i n .


Question: What is Authentication and authorization?

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


Question: What is Verify contexts?

Answer: K u b e r n e t e s   s u p p o r t s   m u l t i p l e   c l u s t e r s   a n d   c o n t e x t s .   E n s u r e   t h a t   y o u   a r e   u s i n g   t h e   c o r r e c t   c o n t e x t   t o   i n t e r a c t   w i t h   y o u r   c l u s t e r .   L i s t   a v a i l a b l e   c o n t e x t s :   k u b e c t l   c o n f i g   g e t - c o n t e x t s   S w i t c h   t o   t h e   a p p r o p r i a t e   c o n t e x t :   k u b e c t l   c o n f i g   u s e - c o n t e x t   < c o n t e x t - n a m e >


Question: What is API server and load balancer?

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


Question: What is TLS problems?

Answer: A d d i t i o n a l   t o o l s   r e q u i r e d   -   b a s e 6 4   a n d   o p e n s s l   v e r s i o n   3 . 0   o r   a b o v e .   T h e   K u b e r n e t e s   A P I   s e r v e r   o n l y   s e r v e s   H T T P S   r e q u e s t s   b y   d e f a u l t .   I n   t h a t   c a s e   T L S   p r o b l e m s   m a y   o c c u r   d u e   t o   v a r i o u s   r e a s o n s ,   s u c h   a s   c e r t i f i c a t e   e x p i r y   o r   c h a i n   o f   t r u s t   v a l i d i t y .   Y o u   c a n   f i n d   t h e   T L S   c e r t i f i c a t e   i n   t h e   k u b e c o n f i g   f i l e ,   l o c a t e d   i n   t h e   ~ / . k u b e / c o n f i g   d i r e c t o r y .   T h e   c e r t i f i c a t e - a u t h o r i t y   a t t r i b u t e   c o n t a i n s   t h e   C A   c e r t i f i c a t e   a n d   t h e   c l i e n t - c e r t i f i c a t e   a t t r i b u t e   c o n t a i n s   t h e   c l i e n t   c e r t i f i c a t e .   V e r i f y   t h e   e x p i r y   o f   t h e s e   c e r t i f i c a t e s :   k u b e c t l   c o n f i g   v i e w   - - f l a t t e n   - - o u t p u t   ' j s o n p a t h = { . c l u s t e r s [ 0 ] . c l u s t e r . c e r t i f i c a t e - a u t h o r i t y - d a t a } '   |   b a s e 6 4   - d   |   o p e n s s l   x 5 0 9   - n o o u t   - d a t e s   o u t p u t :   n o t B e f o r e = F e b   1 3   0 5 : 5 7 : 4 7   2 0 2 4   G M T   n o t A f t e r = F e b   1 0   0 6 : 0 2 : 4 7   2 0 3 4   G M T   k u b e c t l   c o n f i g   v i e w   - - f l a t t e n   - - o u t p u t   ' j s o n p a t h = { . u s e r s [ 0 ] . u s e r . c l i e n t - c e r t i f i c a t e - d a t a } ' |   b a s e 6 4   - d   |   o p e n s s l   x 5 0 9   - n o o u t   - d a t e s   o u t p u t :   n o t B e f o r e = F e b   1 3   0 5 : 5 7 : 4 7   2 0 2 4   G M T   n o t A f t e r = F e b   1 2   0 6 : 0 2 : 5 0   2 0 2 5   G M T


Question: What is Verify kubectl helpers?

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


Question: What is Tutorials?

Answer: This section of the Kubernetes documentation contains tutorials. A tutorial shows how to accomplish a goal that is larger than a single task. Typically a tutorial has several sections, each of which has a sequence of steps. Before walking through each tutorial, you may want to bookmark the Standardized Glossary page for later references.BasicsKubernetes Basics is an in-depth interactive tutorial that helps you understand the Kubernetes system and try out some basic Kubernetes features.Introduction to Kubernetes (edX)Hello MinikubeConfigurationConfiguring Redis Using a ConfigMapAuthoring PodsAdopting Sidecar ContainersStateless ApplicationsExposing an External IP Address to Access an Application in a ClusterExample: Deploying PHP Guestbook application with RedisStateful ApplicationsStatefulSet BasicsExample: WordPress and MySQL with Persistent VolumesExample: Deploying Cassandra with Stateful SetsRunning ZooKeeper, A CP Distributed SystemServicesConnecting Applications with ServicesUsing Source IPSecurityApply Pod Security Standards at Cluster levelApply Pod Security Standards at Namespace levelRestrict a Container's Access to Resources with AppArmorSeccompCluster ManagementConfiguring Swap Memory on Kubernetes NodesRunning Kubelet in Standalone ModeInstall Drivers and Allocate Devices with DRAWhat's nextIf you would like to write a tutorial, see Content Page Types for information about the tutorial page type.


Question: How does Tutorials work?

Answer: This section of the Kubernetes documentation contains tutorials. A tutorial shows how to accomplish a goal that is larger than a single task. Typically a tutorial has several sections, each of which has a sequence of steps. Before walking through each tutorial, you may want to bookmark the Standardized Glossary page for later references.BasicsKubernetes Basics is an in-depth interactive tutorial that helps you understand the Kubernetes system and try out some basic Kubernetes features.Introduction to Kubernetes (edX)Hello MinikubeConfigurationConfiguring Redis Using a ConfigMapAuthoring PodsAdopting Sidecar ContainersStateless ApplicationsExposing an External IP Address to Access an Application in a ClusterExample: Deploying PHP Guestbook application with RedisStateful ApplicationsStatefulSet BasicsExample: WordPress and MySQL with Persistent VolumesExample: Deploying Cassandra with Stateful SetsRunning ZooKeeper, A CP Distributed SystemServicesConnecting Applications with ServicesUsing Source IPSecurityApply Pod Security Standards at Cluster levelApply Pod Security Standards at Namespace levelRestrict a Container's Access to Resources with AppArmorSeccompCluster ManagementConfiguring Swap Memory on Kubernetes NodesRunning Kubelet in Standalone ModeInstall Drivers and Allocate Devices with DRAWhat's nextIf you would like to write a tutorial, see Content Page Types for information about the tutorial page type.


Question: When would you use Tutorials?

Answer: This section of the Kubernetes documentation contains tutorials. A tutorial shows how to accomplish a goal that is larger than a single task. Typically a tutorial has several sections, each of which has a sequence of steps. Before walking through each tutorial, you may want to bookmark the Standardized Glossary page for later references.BasicsKubernetes Basics is an in-depth interactive tutorial that helps you understand the Kubernetes system and try out some basic Kubernetes features.Introduction to Kubernetes (edX)Hello MinikubeConfigurationConfiguring Redis Using a ConfigMapAuthoring PodsAdopting Sidecar ContainersStateless ApplicationsExposing an External IP Address to Access an Application in a ClusterExample: Deploying PHP Guestbook application with RedisStateful ApplicationsStatefulSet BasicsExample: WordPress and MySQL with Persistent VolumesExample: Deploying Cassandra with Stateful SetsRunning ZooKeeper, A CP Distributed SystemServicesConnecting Applications with ServicesUsing Source IPSecurityApply Pod Security Standards at Cluster levelApply Pod Security Standards at Namespace levelRestrict a Container's Access to Resources with AppArmorSeccompCluster ManagementConfiguring Swap Memory on Kubernetes NodesRunning Kubelet in Standalone ModeInstall Drivers and Allocate Devices with DRAWhat's nextIf you would like to write a tutorial, see Content Page Types for information about the tutorial page type.


Question: What are the benefits of Tutorials?

Answer: This section of the Kubernetes documentation contains tutorials. A tutorial shows how to accomplish a goal that is larger than a single task. Typically a tutorial has several sections, each of which has a sequence of steps. Before walking through each tutorial, you may want to bookmark the Standardized Glossary page for later references.BasicsKubernetes Basics is an in-depth interactive tutorial that helps you understand the Kubernetes system and try out some basic Kubernetes features.Introduction to Kubernetes (edX)Hello MinikubeConfigurationConfiguring Redis Using a ConfigMapAuthoring PodsAdopting Sidecar ContainersStateless ApplicationsExposing an External IP Address to Access an Application in a ClusterExample: Deploying PHP Guestbook application with RedisStateful ApplicationsStatefulSet BasicsExample: WordPress and MySQL with Persistent VolumesExample: Deploying Cassandra with Stateful SetsRunning ZooKeeper, A CP Distributed SystemServicesConnecting Applications with ServicesUsing Source IPSecurityApply Pod Security Standards at Cluster levelApply Pod Security Standards at Namespace levelRestrict a Container's Access to Resources with AppArmorSeccompCluster ManagementConfiguring Swap Memory on Kubernetes NodesRunning Kubelet in Standalone ModeInstall Drivers and Allocate Devices with DRAWhat's nextIf you would like to write a tutorial, see Content Page Types for information about the tutorial page type.


Question: What is Tutorials?

Answer: K u b e r n e t e s   D o c u m e n t a t i o n   D o c u m e n t a t i o n   A v a i l a b l e   D o c u m e n t a t i o n   V e r s i o n s   G e t t i n g   s t a r t e d   L e a r n i n g   e n v i r o n m e n t   P r o d u c t i o n   e n v i r o n m e n t   C o n t a i n e r   R u n t i m e s   I n s t a l l i n g   K u b e r n e t e s   w i t h   d e p l o y m e n t   t o o l s   B o o t s t r a p p i n g   c l u s t e r s   w i t h   k u b e a d m   I n s t a l l i n g   k u b e a d m   T r o u b l e s h o o t i n g   k u b e a d m   C r e a t i n g   a   c l u s t e r   w i t h   k u b e a d m   C u s t o m i z i n g   c o m p o n e n t s   w i t h   t h e   k u b e a d m   A P I   O p t i o n s   f o r   H i g h l y   A v a i l a b l e   T o p o l o g y   C r e a t i n g   H i g h l y   A v a i l a b l e   C l u s t e r s   w i t h   k u b e a d m   S e t   u p   a   H i g h   A v a i l a b i l i t y   e t c d   C l u s t e r   w i t h   k u b e a d m   C o n f i g u r i n g   e a c h   k u b e l e t   i n   y o u r   c l u s t e r   u s i n g   k u b e a d m   D u a l - s t a c k   s u p p o r t   w i t h   k u b e a d m   T u r n k e y   C l o u d   S o l u t i o n s   B e s t   p r a c t i c e s   C o n s i d e r a t i o n s   f o r   l a r g e   c l u s t e r s   R u n n i n g   i n   m u l t i p l e   z o n e s   V a l i d a t e   n o d e   s e t u p   E n f o r c i n g   P o d   S e c u r i t y   S t a n d a r d s   P K I   c e r t i f i c a t e s   a n d   r e q u i r e m e n t s   C o n c e p t s   O v e r v i e w   K u b e r n e t e s   C o m p o n e n t s   O b j e c t s   I n   K u b e r n e t e s   K u b e r n e t e s   O b j e c t   M a n a g e m e n t   O b j e c t   N a m e s   a n d   I D s   L a b e l s   a n d   S e l e c t o r s   N a m e s p a c e s   A n n o t a t i o n s   F i e l d   S e l e c t o r s   F i n a l i z e r s   O w n e r s   a n d   D e p e n d e n t s   R e c o m m e n d e d   L a b e l s   T h e   K u b e r n e t e s


Question: What is Basics?

Answer: K u b e r n e t e s   B a s i c s   i s   a n   i n - d e p t h   i n t e r a c t i v e   t u t o r i a l   t h a t   h e l p s   y o u   u n d e r s t a n d   t h e   K u b e r n e t e s   s y s t e m   a n d   t r y   o u t   s o m e   b a s i c   K u b e r n e t e s   f e a t u r e s . I n t r o d u c t i o n   t o   K u b e r n e t e s   ( e d X ) H e l l o   M i n i k u b e


Question: What is Configuration?

Answer: C o n f i g u r i n g   R e d i s   U s i n g   a   C o n f i g M a p


Question: What is Authoring Pods?

Answer: A d o p t i n g   S i d e c a r   C o n t a i n e r s


Question: What is Stateless Applications?

Answer: E x p o s i n g   a n   E x t e r n a l   I P   A d d r e s s   t o   A c c e s s   a n   A p p l i c a t i o n   i n   a   C l u s t e r E x a m p l e :   D e p l o y i n g   P H P   G u e s t b o o k   a p p l i c a t i o n   w i t h   R e d i s


Question: What is Stateful Applications?

Answer: S t a t e f u l S e t   B a s i c s E x a m p l e :   W o r d P r e s s   a n d   M y S Q L   w i t h   P e r s i s t e n t   V o l u m e s E x a m p l e :   D e p l o y i n g   C a s s a n d r a   w i t h   S t a t e f u l   S e t s R u n n i n g   Z o o K e e p e r ,   A   C P   D i s t r i b u t e d   S y s t e m


Question: What is Services?

Answer: C o n n e c t i n g   A p p l i c a t i o n s   w i t h   S e r v i c e s U s i n g   S o u r c e   I P


Question: What is Security?

Answer: A p p l y   P o d   S e c u r i t y   S t a n d a r d s   a t   C l u s t e r   l e v e l A p p l y   P o d   S e c u r i t y   S t a n d a r d s   a t   N a m e s p a c e   l e v e l R e s t r i c t   a   C o n t a i n e r ' s   A c c e s s   t o   R e s o u r c e s   w i t h   A p p A r m o r S e c c o m p


Question: What is Cluster Management?

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


Question: What is What's next?

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


Question: What is Creating Highly Available Clusters with kubeadm?

Answer: Creating Highly Available Clusters with kubeadmThis page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm:With stacked control plane nodes. This approach requires less infrastructure. The etcd members and control plane nodes are co-located.With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated.Before proceeding, you should carefully consider which approach best meets the needs of your applications and environment. Options for Highly Available topology outlines the advantages and disadvantages of each.If you encounter issues with setting up the HA cluster, please report these in the kubeadm issue tracker.See also the upgrade documentation.Caution:This page does not address running your cluster on a cloud provider. In a cloud environment, neither approach documented here works with Service objects of type LoadBalancer, or with dynamic PersistentVolumes.Before you beginThe prerequisites depend on which topology you have selected for your cluster's control plane:You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.See Stacked etcd topology for context.You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.And you also need:Three or more additional machines, that will become etcd cluster members. Having an odd number of members in the etcd cluster is a requirement for achieving optimal voting quorum.These machines again need to have kubeadm and kubelet installed.These machines also require a container runtime, that is already set up and working.See External etcd topology for context.Container imagesEach host should have acc


Question: How does Creating Highly Available Clusters with kubeadm work?

Answer: Creating Highly Available Clusters with kubeadmThis page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm:With stacked control plane nodes. This approach requires less infrastructure. The etcd members and control plane nodes are co-located.With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated.Before proceeding, you should carefully consider which approach best meets the needs of your applications and environment. Options for Highly Available topology outlines the advantages and disadvantages of each.If you encounter issues with setting up the HA cluster, please report these in the kubeadm issue tracker.See also the upgrade documentation.Caution:This page does not address running your cluster on a cloud provider. In a cloud environment, neither approach documented here works with Service objects of type LoadBalancer, or with dynamic PersistentVolumes.Before you beginThe prerequisites depend on which topology you have selected for your cluster's control plane:You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.See Stacked etcd topology for context.You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.And you also need:Three or more additional machines, that will become etcd cluster members. Having an odd number of members in the etcd cluster is a requirement for achieving optimal voting quorum.These machines again need to have kubeadm and kubelet installed.These machines also require a container runtime, that is already set up and working.See External etcd topology for context.Container imagesEach host should have acc


Question: When would you use Creating Highly Available Clusters with kubeadm?

Answer: Creating Highly Available Clusters with kubeadmThis page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm:With stacked control plane nodes. This approach requires less infrastructure. The etcd members and control plane nodes are co-located.With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated.Before proceeding, you should carefully consider which approach best meets the needs of your applications and environment. Options for Highly Available topology outlines the advantages and disadvantages of each.If you encounter issues with setting up the HA cluster, please report these in the kubeadm issue tracker.See also the upgrade documentation.Caution:This page does not address running your cluster on a cloud provider. In a cloud environment, neither approach documented here works with Service objects of type LoadBalancer, or with dynamic PersistentVolumes.Before you beginThe prerequisites depend on which topology you have selected for your cluster's control plane:You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.See Stacked etcd topology for context.You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.And you also need:Three or more additional machines, that will become etcd cluster members. Having an odd number of members in the etcd cluster is a requirement for achieving optimal voting quorum.These machines again need to have kubeadm and kubelet installed.These machines also require a container runtime, that is already set up and working.See External etcd topology for context.Container imagesEach host should have acc


Question: What are the benefits of Creating Highly Available Clusters with kubeadm?

Answer: Creating Highly Available Clusters with kubeadmThis page explains two different approaches to setting up a highly available Kubernetes cluster using kubeadm:With stacked control plane nodes. This approach requires less infrastructure. The etcd members and control plane nodes are co-located.With an external etcd cluster. This approach requires more infrastructure. The control plane nodes and etcd members are separated.Before proceeding, you should carefully consider which approach best meets the needs of your applications and environment. Options for Highly Available topology outlines the advantages and disadvantages of each.If you encounter issues with setting up the HA cluster, please report these in the kubeadm issue tracker.See also the upgrade documentation.Caution:This page does not address running your cluster on a cloud provider. In a cloud environment, neither approach documented here works with Service objects of type LoadBalancer, or with dynamic PersistentVolumes.Before you beginThe prerequisites depend on which topology you have selected for your cluster's control plane:You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.See Stacked etcd topology for context.You need:Three or more machines that meet kubeadm's minimum requirements for the control-plane nodes. Having an odd number of control plane nodes can help with leader selection in the case of machine or zone failure.including a container runtime, already set up and workingThree or more machines that meet kubeadm's minimum requirements for the workersincluding a container runtime, already set up and workingFull network connectivity between all machines in the cluster (public or private network)Superuser privileges on all machines using sudoYou can use a different tool; this guide uses sudo in the examples.SSH access from one device to all nodes in the systemkubeadm and kubelet already installed on all machines.And you also need:Three or more additional machines, that will become etcd cluster members. Having an odd number of members in the etcd cluster is a requirement for achieving optimal voting quorum.These machines again need to have kubeadm and kubelet installed.These machines also require a container runtime, that is already set up and working.See External etcd topology for context.Container imagesEach host should have acc


Question: What is Creating Highly Available Clusters with kubeadm?

Answer: T h i s   p a g e   e x p l a i n s   t w o   d i f f e r e n t   a p p r o a c h e s   t o   s e t t i n g   u p   a   h i g h l y   a v a i l a b l e   K u b e r n e t e s   c l u s t e r   u s i n g   k u b e a d m :   W i t h   s t a c k e d   c o n t r o l   p l a n e   n o d e s .   T h i s   a p p r o a c h   r e q u i r e s   l e s s   i n f r a s t r u c t u r e .   T h e   e t c d   m e m b e r s   a n d   c o n t r o l   p l a n e   n o d e s   a r e   c o - l o c a t e d . W i t h   a n   e x t e r n a l   e t c d   c l u s t e r .   T h i s   a p p r o a c h   r e q u i r e s   m o r e   i n f r a s t r u c t u r e .   T h e   c o n t r o l   p l a n e   n o d e s   a n d   e t c d   m e m b e r s   a r e   s e p a r a t e d .   B e f o r e   p r o c e e d i n g ,   y o u   s h o u l d   c a r e f u l l y   c o n s i d e r   w h i c h   a p p r o a c h   b e s t   m e e t s   t h e   n e e d s   o f   y o u r   a p p l i c a t i o n s   a n d   e n v i r o n m e n t .   O p t i o n s   f o r   H i g h l y   A v a i l a b l e   t o p o l o g y   o u t l i n e s   t h e   a d v a n t a g e s   a n d   d i s a d v a n t a g e s   o f   e a c h .   I f   y o u   e n c o u n t e r   i s s u e s   w i t h   s e t t i n g   u p   t h e   H A   c l u s t e r ,   p l e a s e   r e p o r t   t h e s e   i n   t h e   k u b e a d m   i s s u e   t r a c k e r .   S e e   a l s o   t h e   u p g r a d e   d o c u m e n t a t i o n .


Question: What is Before you begin?

Answer: T h e   p r e r e q u i s i t e s   d e p e n d   o n   w h i c h   t o p o l o g y   y o u   h a v e   s e l e c t e d   f o r   y o u r   c l u s t e r ' s   c o n t r o l   p l a n e :   Y o u   n e e d : T h r e e   o r   m o r e   m a c h i n e s   t h a t   m e e t   k u b e a d m ' s   m i n i m u m   r e q u i r e m e n t s   f o r   t h e   c o n t r o l - p l a n e   n o d e s .   H a v i n g   a n   o d d   n u m b e r   o f   c o n t r o l   p l a n e   n o d e s   c a n   h e l p   w i t h   l e a d e r   s e l e c t i o n   i n   t h e   c a s e   o f   m a c h i n e   o r   z o n e   f a i l u r e . i n c l u d i n g   a   c o n t a i n e r   r u n t i m e ,   a l r e a d y   s e t   u p   a n d   w o r k i n g T h r e e   o r   m o r e   m a c h i n e s   t h a t   m e e t   k u b e a d m ' s   m i n i m u m   r e q u i r e m e n t s   f o r   t h e   w o r k e r s i n c l u d i n g   a   c o n t a i n e r   r u n t i m e ,   a l r e a d y   s e t   u p   a n d   w o r k i n g F u l l   n e t w o r k   c o n n e c t i v i t y   b e t w e e n   a l l   m a c h i n e s   i n   t h e   c l u s t e r   ( p u b l i c   o r   p r i v a t e   n e t w o r k ) S u p e r u s e r   p r i v i l e g e s   o n   a l l   m a c h i n e s   u s i n g   s u d o Y o u   c a n   u s e   a   d i f f e r e n t   t o o l ;   t h i s   g u i d e   u s e s   s u d o   i n   t h e   e x a m p l e s . S S H   a c c e s s   f r o m   o n e   d e v i c e   t o   a l l   n o d e s   i n   t h e   s y s t e m k u b e a d m   a n d   k u b e l e t   a l r e a d y   i n s t a l l e d   o n   a l l   m a c h i n e s . S e e   S t a c k e d   e t c d   t o p o l o g y   f o r   c o n t e x t .   Y o u   n e e d :   T h r e e   o r   m o r e   m a c h i n e s   t h a t   m e e t   k u b e a d m ' s   m i n i m u m   r e q u i r e m e n t s   f o r   t h e   c o n t r o l - p l a n e   n o d e s .   H a v i n g   a n   o d d   n u m b e r   o f   c o n t r o l   p l a n e   n o d e s


Question: What is Container images?

Answer: E a c h   h o s t   s h o u l d   h a v e   a c c e s s   r e a d   a n d   f e t c h   i m a g e s   f r o m   t h e   K u b e r n e t e s   c o n t a i n e r   i m a g e   r e g i s t r y ,   r e g i s t r y . k 8 s . i o .   I f   y o u   w a n t   t o   d e p l o y   a   h i g h l y - a v a i l a b l e   c l u s t e r   w h e r e   t h e   h o s t s   d o   n o t   h a v e   a c c e s s   t o   p u l l   i m a g e s ,   t h i s   i s   p o s s i b l e .   Y o u   m u s t   e n s u r e   b y   s o m e   o t h e r   m e a n s   t h a t   t h e   c o r r e c t   c o n t a i n e r   i m a g e s   a r e   a l r e a d y   a v a i l a b l e   o n   t h e   r e l e v a n t   h o s t s .


Question: What is Command line interface?

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


Question: What is Note:?

Answer: C r e a t e   a   k u b e - a p i s e r v e r   l o a d   b a l a n c e r   w i t h   a   n a m e   t h a t   r e s o l v e s   t o   D N S . I n   a   c l o u d   e n v i r o n m e n t   y o u   s h o u l d   p l a c e   y o u r   c o n t r o l   p l a n e   n o d e s   b e h i n d   a   T C P   f o r w a r d i n g   l o a d   b a l a n c e r .   T h i s   l o a d   b a l a n c e r   d i s t r i b u t e s   t r a f f i c   t o   a l l   h e a l t h y   c o n t r o l   p l a n e   n o d e s   i n   i t s   t a r g e t   l i s t .   T h e   h e a l t h   c h e c k   f o r   a n   a p i s e r v e r   i s   a   T C P   c h e c k   o n   t h e   p o r t   t h e   k u b e - a p i s e r v e r   l i s t e n s   o n   ( d e f a u l t   v a l u e   : 6 4 4 3 ) . I t   i s   n o t   r e c o m m e n d e d   t o   u s e   a n   I P   a d d r e s s   d i r e c t l y   i n   a   c l o u d   e n v i r o n m e n t . T h e   l o a d   b a l a n c e r   m u s t   b e   a b l e   t o   c o m m u n i c a t e   w i t h   a l l   c o n t r o l   p l a n e   n o d e s   o n   t h e   a p i s e r v e r   p o r t .   I t   m u s t   a l s o   a l l o w   i n c o m i n g   t r a f f i c   o n   i t s   l i s t e n i n g   p o r t . M a k e   s u r e   t h e   a d d r e s s   o f   t h e   l o a d   b a l a n c e r   a l w a y s   m a t c h e s   t h e   a d d r e s s   o f   k u b e a d m ' s   C o n t r o l P l a n e E n d p o i n t . R e a d   t h e   O p t i o n s   f o r   S o f t w a r e   L o a d   B a l a n c i n g   g u i d e   f o r   m o r e   d e t a i l s . A d d   t h e   f i r s t   c o n t r o l   p l a n e   n o d e   t o   t h e   l o a d   b a l a n c e r ,   a n d   t e s t   t h e   c o n n e c t i o n : n c   - z v   - w   2   < L O A D _ B A L A N C E R _ I P >   < P O R T >   A   c o n n e c t i o n   r e f u s e d   e r r o r   i s   e x p e c t e d   b e c a u s e   t h e   A P I   s e r v e r   i s   n o t   y e t   r u n n i n g .   A   t i m e o u t ,   h o w e v


Question: What is Steps for the first control plane node?

Answer: I n i t i a l i z e   t h e   c o n t r o l   p l a n e : s u d o   k u b e a d m   i n i t   - - c o n t r o l - p l a n e - e n d p o i n t   " L O A D _ B A L A N C E R _ D N S : L O A D _ B A L A N C E R _ P O R T "   - - u p l o a d - c e r t s   Y o u   c a n   u s e   t h e   - - k u b e r n e t e s - v e r s i o n   f l a g   t o   s e t   t h e   K u b e r n e t e s   v e r s i o n   t o   u s e .   I t   i s   r e c o m m e n d e d   t h a t   t h e   v e r s i o n s   o f   k u b e a d m ,   k u b e l e t ,   k u b e c t l   a n d   K u b e r n e t e s   m a t c h . T h e   - - c o n t r o l - p l a n e - e n d p o i n t   f l a g   s h o u l d   b e   s e t   t o   t h e   a d d r e s s   o r   D N S   a n d   p o r t   o f   t h e   l o a d   b a l a n c e r . T h e   - - u p l o a d - c e r t s   f l a g   i s   u s e d   t o   u p l o a d   t h e   c e r t i f i c a t e s   t h a t   s h o u l d   b e   s h a r e d   a c r o s s   a l l   t h e   c o n t r o l - p l a n e   i n s t a n c e s   t o   t h e   c l u s t e r .   I f   i n s t e a d ,   y o u   p r e f e r   t o   c o p y   c e r t s   a c r o s s   c o n t r o l - p l a n e   n o d e s   m a n u a l l y   o r   u s i n g   a u t o m a t i o n   t o o l s ,   p l e a s e   r e m o v e   t h i s   f l a g   a n d   r e f e r   t o   M a n u a l   c e r t i f i c a t e   d i s t r i b u t i o n   s e c t i o n   b e l o w . N o t e : T h e   k u b e a d m   i n i t   f l a g s   - - c o n f i g   a n d   - - c e r t i f i c a t e - k e y   c a n n o t   b e   m i x e d ,   t h e r e f o r e   i f   y o u   w a n t   t o   u s e   t h e   k u b e a d m   c o n f i g u r a t i o n   y o u   m u s t   a d d   t h e   c e r t i f i c a t e K e y   f i e l d   i n   t h e   a p p r o p r i a t e   c o n f i g   l o c a t i o n s   ( u n d e r   I n i t C o n f i g u r a t i o n   a n d   J o i n C o n f i g u r a t i o n :   c o n t r o l P l a n e ) . N o t e : S o m e   C N I   n e t w o r k


Question: What is Note:?

Answer: T h e   o u t p u t   l o o k s   s i m i l a r   t o :   . . .   Y o u   c a n   n o w   j o i n   a n y   n u m b e r   o f   c o n t r o l - p l a n e   n o d e   b y   r u n n i n g   t h e   f o l l o w i n g   c o m m a n d   o n   e a c h   a s   a   r o o t :   k u b e a d m   j o i n   1 9 2 . 1 6 8 . 0 . 2 0 0 : 6 4 4 3   - - t o k e n   9 v r 7 3 a . a 8 u x y a j u 7 9 9 q w d j v   - - d i s c o v e r y - t o k e n - c a - c e r t - h a s h   s h a 2 5 6 : 7 c 2 e 6 9 1 3 1 a 3 6 a e 2 a 0 4 2 a 3 3 9 b 3 3 3 8 1 c 6 d 0 d 4 3 8 8 7 e 2 d e 8 3 7 2 0 e f f 5 3 5 9 e 2 6 a e c 8 6 6   - - c o n t r o l - p l a n e   - - c e r t i f i c a t e - k e y   f 8 9 0 2 e 1 1 4 e f 1 1 8 3 0 4 e 5 6 1 c 3 e c d 4 d 0 b 5 4 3 a d c 2 2 6 b 7 a 0 7 f 6 7 5 f 5 6 5 6 4 1 8 5 f f e 0 c 0 7   P l e a s e   n o t e   t h a t   t h e   c e r t i f i c a t e - k e y   g i v e s   a c c e s s   t o   c l u s t e r   s e n s i t i v e   d a t a ,   k e e p   i t   s e c r e t !   A s   a   s a f e g u a r d ,   u p l o a d e d - c e r t s   w i l l   b e   d e l e t e d   i n   t w o   h o u r s ;   I f   n e c e s s a r y ,   y o u   c a n   u s e   k u b e a d m   i n i t   p h a s e   u p l o a d - c e r t s   t o   r e l o a d   c e r t s   a f t e r w a r d .   T h e n   y o u   c a n   j o i n   a n y   n u m b e r   o f   w o r k e r   n o d e s   b y   r u n n i n g   t h e   f o l l o w i n g   o n   e a c h   a s   r o o t :   k u b e a d m   j o i n   1 9 2 . 1 6 8 . 0 . 2 0 0 : 6 4 4 3   - - t o k e n   9 v r 7 3 a . a 8 u x y a j u 7 9 9 q w d j v   - - d i s c o v e r y - t o k e n - c a - c e r t - h a s h   s h a 2 5 6 : 7 c 2 e 6 9 1 3 1 a 3 6 a e 2 a 0 4 2 a 3 3 9 b 3 3 3 8 1 c 6 d 0 d 4 3 8 8 7 e 2 d e 8 3 7 2 0 e f f 5 3 5 9 e 2 6 a e c 8 6 6   C o p y   t h i s   o u t p u t   t o   a   t e x t   f i l e .   Y o u   w i l l   n e e d   i t   l a t e r   t o   j o i n   c o n t r o l   p l a n e   a n d   w o r k e r   n o d e s   t o   t h e   c l u s


Question: What is Caution:?

Answer: A p p l y   t h e   C N I   p l u g i n   o f   y o u r   c h o i c e :   F o l l o w   t h e s e   i n s t r u c t i o n s   t o   i n s t a l l   t h e   C N I   p r o v i d e r .   M a k e   s u r e   t h e   c o n f i g u r a t i o n   c o r r e s p o n d s   t o   t h e   P o d   C I D R   s p e c i f i e d   i n   t h e   k u b e a d m   c o n f i g u r a t i o n   f i l e   ( i f   a p p l i c a b l e ) .


Question: What is Note:?

Answer: T y p e   t h e   f o l l o w i n g   a n d   w a t c h   t h e   p o d s   o f   t h e   c o n t r o l   p l a n e   c o m p o n e n t s   g e t   s t a r t e d :   k u b e c t l   g e t   p o d   - n   k u b e - s y s t e m   - w


Question: What is Steps for the rest of the control plane nodes?

Answer: F o r   e a c h   a d d i t i o n a l   c o n t r o l   p l a n e   n o d e   y o u   s h o u l d :   E x e c u t e   t h e   j o i n   c o m m a n d   t h a t   w a s   p r e v i o u s l y   g i v e n   t o   y o u   b y   t h e   k u b e a d m   i n i t   o u t p u t   o n   t h e   f i r s t   n o d e .   I t   s h o u l d   l o o k   s o m e t h i n g   l i k e   t h i s : s u d o   k u b e a d m   j o i n   1 9 2 . 1 6 8 . 0 . 2 0 0 : 6 4 4 3   - - t o k e n   9 v r 7 3 a . a 8 u x y a j u 7 9 9 q w d j v   - - d i s c o v e r y - t o k e n - c a - c e r t - h a s h   s h a 2 5 6 : 7 c 2 e 6 9 1 3 1 a 3 6 a e 2 a 0 4 2 a 3 3 9 b 3 3 3 8 1 c 6 d 0 d 4 3 8 8 7 e 2 d e 8 3 7 2 0 e f f 5 3 5 9 e 2 6 a e c 8 6 6   - - c o n t r o l - p l a n e   - - c e r t i f i c a t e - k e y   f 8 9 0 2 e 1 1 4 e f 1 1 8 3 0 4 e 5 6 1 c 3 e c d 4 d 0 b 5 4 3 a d c 2 2 6 b 7 a 0 7 f 6 7 5 f 5 6 5 6 4 1 8 5 f f e 0 c 0 7   T h e   - - c o n t r o l - p l a n e   f l a g   t e l l s   k u b e a d m   j o i n   t o   c r e a t e   a   n e w   c o n t r o l   p l a n e . T h e   - - c e r t i f i c a t e - k e y   . . .   w i l l   c a u s e   t h e   c o n t r o l   p l a n e   c e r t i f i c a t e s   t o   b e   d o w n l o a d e d   f r o m   t h e   k u b e a d m - c e r t s   S e c r e t   i n   t h e   c l u s t e r   a n d   b e   d e c r y p t e d   u s i n g   t h e   g i v e n   k e y .   E x e c u t e   t h e   j o i n   c o m m a n d   t h a t   w a s   p r e v i o u s l y   g i v e n   t o   y o u   b y   t h e   k u b e a d m   i n i t   o u t p u t   o n   t h e   f i r s t   n o d e .   I t   s h o u l d   l o o k   s o m e t h i n g   l i k e   t h i s :   s u d o   k u b e a d m   j o i n   1 9 2 . 1 6 8 . 0 . 2 0 0 : 6 4 4 3   - - t o k e n   9 v r 7 3 a . a 8 u x y a j u 7 9 9 q w d j v   - - d i s c o v e r y - t o k e n - c a - c e r t - h a s h   s h a 2 5 6 : 7 c 2 e 6 9 1 3 1 a 3 6 a e 2 a 0 4 2 a 3 3 9 b 3 3 3 8 1 c 6 d 0 d 4 3 8 8 7 e 2 d e 8 3 7 2 0 e f


Question: What is External etcd nodes?

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


Question: What is Set up the etcd cluster?

Answer: F o l l o w   t h e s e   i n s t r u c t i o n s   t o   s e t   u p   t h e   e t c d   c l u s t e r . S e t   u p   S S H   a s   d e s c r i b e d   h e r e . C o p y   t h e   f o l l o w i n g   f i l e s   f r o m   a n y   e t c d   n o d e   i n   t h e   c l u s t e r   t o   t h e   f i r s t   c o n t r o l   p l a n e   n o d e : e x p o r t   C O N T R O L _ P L A N E = " u b u n t u @ 1 0 . 0 . 0 . 7 "   s c p   / e t c / k u b e r n e t e s / p k i / e t c d / c a . c r t   " $ { C O N T R O L _ P L A N E } " :   s c p   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . c r t   " $ { C O N T R O L _ P L A N E } " :   s c p   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . k e y   " $ { C O N T R O L _ P L A N E } " :   R e p l a c e   t h e   v a l u e   o f   C O N T R O L _ P L A N E   w i t h   t h e   u s e r @ h o s t   o f   t h e   f i r s t   c o n t r o l - p l a n e   n o d e .   F o l l o w   t h e s e   i n s t r u c t i o n s   t o   s e t   u p   t h e   e t c d   c l u s t e r .   S e t   u p   S S H   a s   d e s c r i b e d   h e r e .   C o p y   t h e   f o l l o w i n g   f i l e s   f r o m   a n y   e t c d   n o d e   i n   t h e   c l u s t e r   t o   t h e   f i r s t   c o n t r o l   p l a n e   n o d e :   e x p o r t   C O N T R O L _ P L A N E = " u b u n t u @ 1 0 . 0 . 0 . 7 "   s c p   / e t c / k u b e r n e t e s / p k i / e t c d / c a . c r t   " $ { C O N T R O L _ P L A N E } " :   s c p   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . c r t   " $ { C O N T R O L _ P L A N E } " :   s c p   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . k e y   " $ { C O N T R O L _ P L A N E } " :   R e p l a c e   t h e   v a l u e   o f   C O N T R O L _ P L A N E   w i t h   t h e   u s e r @ h o s t   o f   t h e   f i r s t   c o n t r o l - p l a n e   n o d e .


Question: What is Set up the first control plane node?

Answer: C r e a t e   a   f i l e   c a l l e d   k u b e a d m - c o n f i g . y a m l   w i t h   t h e   f o l l o w i n g   c o n t e n t s : - - -   a p i V e r s i o n :   k u b e a d m . k 8 s . i o / v 1 b e t a 4   k i n d :   C l u s t e r C o n f i g u r a t i o n   k u b e r n e t e s V e r s i o n :   s t a b l e   c o n t r o l P l a n e E n d p o i n t :   " L O A D _ B A L A N C E R _ D N S : L O A D _ B A L A N C E R _ P O R T "   #   c h a n g e   t h i s   ( s e e   b e l o w )   e t c d :   e x t e r n a l :   e n d p o i n t s :   -   h t t p s : / / E T C D _ 0 _ I P : 2 3 7 9   #   c h a n g e   E T C D _ 0 _ I P   a p p r o p r i a t e l y   -   h t t p s : / / E T C D _ 1 _ I P : 2 3 7 9   #   c h a n g e   E T C D _ 1 _ I P   a p p r o p r i a t e l y   -   h t t p s : / / E T C D _ 2 _ I P : 2 3 7 9   #   c h a n g e   E T C D _ 2 _ I P   a p p r o p r i a t e l y   c a F i l e :   / e t c / k u b e r n e t e s / p k i / e t c d / c a . c r t   c e r t F i l e :   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . c r t   k e y F i l e :   / e t c / k u b e r n e t e s / p k i / a p i s e r v e r - e t c d - c l i e n t . k e y   N o t e : T h e   d i f f e r e n c e   b e t w e e n   s t a c k e d   e t c d   a n d   e x t e r n a l   e t c d   h e r e   i s   t h a t   t h e   e x t e r n a l   e t c d   s e t u p   r e q u i r e s   a   c o n f i g u r a t i o n   f i l e   w i t h   t h e   e t c d   e n d p o i n t s   u n d e r   t h e   e x t e r n a l   o b j e c t   f o r   e t c d .   I n   t h e   c a s e   o f   t h e   s t a c k e d   e t c d   t o p o l o g y ,   t h i s   i s   m a n a g e d   a u t o m a t i c a l l y . R e p l a c e   t h e   f o l l o w i n g   v a r i a b l e s   i n   t h e   c o n f i g   t e m p l a t e   w i t h   t h e   a p p r o p r i a t e   v a l u e s   f o r   y o u r   c l u s t e r : L O A D _ B A L A N C E R _ D N S L O A D _ B A L A N C E R _ P O R T E T C D _ 0 _


Question: What is Note:?

Answer: R e p l a c e   t h e   f o l l o w i n g   v a r i a b l e s   i n   t h e   c o n f i g   t e m p l a t e   w i t h   t h e   a p p r o p r i a t e   v a l u e s   f o r   y o u r   c l u s t e r : L O A D _ B A L A N C E R _ D N S L O A D _ B A L A N C E R _ P O R T E T C D _ 0 _ I P E T C D _ 1 _ I P E T C D _ 2 _ I P   R e p l a c e   t h e   f o l l o w i n g   v a r i a b l e s   i n   t h e   c o n f i g   t e m p l a t e   w i t h   t h e   a p p r o p r i a t e   v a l u e s   f o r   y o u r   c l u s t e r :   L O A D _ B A L A N C E R _ D N S L O A D _ B A L A N C E R _ P O R T E T C D _ 0 _ I P E T C D _ 1 _ I P E T C D _ 2 _ I P   T h e   f o l l o w i n g   s t e p s   a r e   s i m i l a r   t o   t h e   s t a c k e d   e t c d   s e t u p :   R u n   s u d o   k u b e a d m   i n i t   - - c o n f i g   k u b e a d m - c o n f i g . y a m l   - - u p l o a d - c e r t s   o n   t h i s   n o d e . W r i t e   t h e   o u t p u t   j o i n   c o m m a n d s   t h a t   a r e   r e t u r n e d   t o   a   t e x t   f i l e   f o r   l a t e r   u s e . A p p l y   t h e   C N I   p l u g i n   o f   y o u r   c h o i c e . N o t e : Y o u   m u s t   p i c k   a   n e t w o r k   p l u g i n   t h a t   s u i t s   y o u r   u s e   c a s e   a n d   d e p l o y   i t   b e f o r e   y o u   m o v e   o n   t o   n e x t   s t e p .   I f   y o u   d o n ' t   d o   t h i s ,   y o u   w i l l   n o t   b e   a b l e   t o   l a u n c h   y o u r   c l u s t e r   p r o p e r l y .   R u n   s u d o   k u b e a d m   i n i t   - - c o n f i g   k u b e a d m - c o n f i g . y a m l   - - u p l o a d - c e r t s   o n   t h i s   n o d e .   W r i t e   t h e   o u t p u t   j o i n   c o m m a n d s   t h a t   a r e   r e t u r n e d   t o   a   t e x t   f i l e   f o r   l a t e r   u s e .   A p p l y   t h e   C N I   p l u g i n   o f   y o u r   c h o i c e .


Question: What is Steps for the rest of the control plane nodes?

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


Question: What is Install workers?

Answer: W o r k e r   n o d e s   c a n   b e   j o i n e d   t o   t h e   c l u s t e r   w i t h   t h e   c o m m a n d   y o u   s t o r e d   p r e v i o u s l y   a s   t h e   o u t p u t   f r o m   t h e   k u b e a d m   i n i t   c o m m a n d :   s u d o   k u b e a d m   j o i n   1 9 2 . 1 6 8 . 0 . 2 0 0 : 6 4 4 3   - - t o k e n   9 v r 7 3 a . a 8 u x y a j u 7 9 9 q w d j v   - - d i s c o v e r y - t o k e n - c a - c e r t - h a s h   s h a 2 5 6 : 7 c 2 e 6 9 1 3 1 a 3 6 a e 2 a 0 4 2 a 3 3 9 b 3 3 3 8 1 c 6 d 0 d 4 3 8 8 7 e 2 d e 8 3 7 2 0 e f f 5 3 5 9 e 2 6 a e c 8 6 6


Question: What is Manual certificate distribution?

Answer: I f   y o u   c h o o s e   t o   n o t   u s e   k u b e a d m   i n i t   w i t h   t h e   - - u p l o a d - c e r t s   f l a g   t h i s   m e a n s   t h a t   y o u   a r e   g o i n g   t o   h a v e   t o   m a n u a l l y   c o p y   t h e   c e r t i f i c a t e s   f r o m   t h e   p r i m a r y   c o n t r o l   p l a n e   n o d e   t o   t h e   j o i n i n g   c o n t r o l   p l a n e   n o d e s .   T h e r e   a r e   m a n y   w a y s   t o   d o   t h i s .   T h e   f o l l o w i n g   e x a m p l e   u s e s   s s h   a n d   s c p :   S S H   i s   r e q u i r e d   i f   y o u   w a n t   t o   c o n t r o l   a l l   n o d e s   f r o m   a   s i n g l e   m a c h i n e .   E n a b l e   s s h - a g e n t   o n   y o u r   m a i n   d e v i c e   t h a t   h a s   a c c e s s   t o   a l l   o t h e r   n o d e s   i n   t h e   s y s t e m : e v a l   $ ( s s h - a g e n t )   A d d   y o u r   S S H   i d e n t i t y   t o   t h e   s e s s i o n : s s h - a d d   ~ / . s s h / p a t h _ t o _ p r i v a t e _ k e y   S S H   b e t w e e n   n o d e s   t o   c h e c k   t h a t   t h e   c o n n e c t i o n   i s   w o r k i n g   c o r r e c t l y . W h e n   y o u   S S H   t o   a n y   n o d e ,   a d d   t h e   - A   f l a g .   T h i s   f l a g   a l l o w s   t h e   n o d e   t h a t   y o u   h a v e   l o g g e d   i n t o   v i a   S S H   t o   a c c e s s   t h e   S S H   a g e n t   o n   y o u r   P C .   C o n s i d e r   a l t e r n a t i v e   m e t h o d s   i f   y o u   d o   n o t   f u l l y   t r u s t   t h e   s e c u r i t y   o f   y o u r   u s e r   s e s s i o n   o n   t h e   n o d e . s s h   - A   1 0 . 0 . 0 . 7   W h e n   u s i n g   s u d o   o n   a n y   n o d e ,   m a k e   s u r e   t o   p r e s e r v e   t h e   e n v i r o n m e n t   s o   S S H   f o r w a r d i n g   w o r k s : s u d o   - E   - s   A f t e r   c o n f i g u r i n g   S S H   o n   a l l   t h e   n o d e s   y o u


Question: What is Caution:?

Answer: T h e n   o n   e a c h   j o i n i n g   c o n t r o l   p l a n e   n o d e   y o u   h a v e   t o   r u n   t h e   f o l l o w i n g   s c r i p t   b e f o r e   r u n n i n g   k u b e a d m   j o i n .   T h i s   s c r i p t   w i l l   m o v e   t h e   p r e v i o u s l y   c o p i e d   c e r t i f i c a t e s   f r o m   t h e   h o m e   d i r e c t o r y   t o   / e t c / k u b e r n e t e s / p k i :   U S E R = u b u n t u   #   c u s t o m i z a b l e   m k d i r   - p   / e t c / k u b e r n e t e s / p k i / e t c d   m v   / h o m e / $ { U S E R } / c a . c r t   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / c a . k e y   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / s a . p u b   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / s a . k e y   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / f r o n t - p r o x y - c a . c r t   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / f r o n t - p r o x y - c a . k e y   / e t c / k u b e r n e t e s / p k i /   m v   / h o m e / $ { U S E R } / e t c d - c a . c r t   / e t c / k u b e r n e t e s / p k i / e t c d / c a . c r t   #   S k i p   t h e   n e x t   l i n e   i f   y o u   a r e   u s i n g   e x t e r n a l   e t c d   m v   / h o m e / $ { U S E R } / e t c d - c a . k e y   / e t c / k u b e r n e t e s / p k i / e t c d / c a . k e y


Question: What is Configure Liveness, Readiness and Startup Probes?

Answer: Configure Liveness, Readiness and Startup ProbesThis page shows how to configure liveness, readiness and startup probes for containers.For more information about probes, see Liveness, Readiness and Startup ProbesThe kubelet uses liveness probes to know when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress. Restarting a container in such a state can help to make the application more available despite bugs.A common pattern for liveness probes is to use the same low-cost HTTP endpoint as for readiness probes, but with a higher failureThreshold. This ensures that the pod is observed as not-ready for some period of time before it is hard killed.The kubelet uses readiness probes to know when a container is ready to start accepting traffic. One use of this signal is to control which Pods are used as backends for Services. A Pod is considered ready when its Ready condition is true. When a Pod is not ready, it is removed from Service load balancers. A Pod's Ready condition is false when its Node's Ready condition is not true, when one of the Pod's readinessGates is false, or when at least one of its containers is not ready.The kubelet uses startup probes to know when a container application has started. If such a probe is configured, liveness and readiness probes do not start until it succeeds, making sure those probes don't interfere with the application startup. This can be used to adopt liveness checks on slow starting containers, avoiding them getting killed by the kubelet before they are up and running.Caution:Liveness probes can be a powerful way to recover from application failures, but they should be used with caution. Liveness probes must be configured carefully to ensure that they truly indicate unrecoverable application failure, for example a deadlock.Note:Incorrect implementation of liveness probes can lead to cascading failures. This results in restarting of container under high load; failed client requests as your application became less scalable; and increased workload on remaining pods due to some failed pods. Understand the difference between readiness and liveness probes and when to apply them for your app.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 KubernetesDefine a liveness commandMany applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations.In this exercise, you create a Pod that runs a container based on the registry.k8s.i


Question: How does Configure Liveness, Readiness and Startup Probes work?

Answer: Configure Liveness, Readiness and Startup ProbesThis page shows how to configure liveness, readiness and startup probes for containers.For more information about probes, see Liveness, Readiness and Startup ProbesThe kubelet uses liveness probes to know when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress. Restarting a container in such a state can help to make the application more available despite bugs.A common pattern for liveness probes is to use the same low-cost HTTP endpoint as for readiness probes, but with a higher failureThreshold. This ensures that the pod is observed as not-ready for some period of time before it is hard killed.The kubelet uses readiness probes to know when a container is ready to start accepting traffic. One use of this signal is to control which Pods are used as backends for Services. A Pod is considered ready when its Ready condition is true. When a Pod is not ready, it is removed from Service load balancers. A Pod's Ready condition is false when its Node's Ready condition is not true, when one of the Pod's readinessGates is false, or when at least one of its containers is not ready.The kubelet uses startup probes to know when a container application has started. If such a probe is configured, liveness and readiness probes do not start until it succeeds, making sure those probes don't interfere with the application startup. This can be used to adopt liveness checks on slow starting containers, avoiding them getting killed by the kubelet before they are up and running.Caution:Liveness probes can be a powerful way to recover from application failures, but they should be used with caution. Liveness probes must be configured carefully to ensure that they truly indicate unrecoverable application failure, for example a deadlock.Note:Incorrect implementation of liveness probes can lead to cascading failures. This results in restarting of container under high load; failed client requests as your application became less scalable; and increased workload on remaining pods due to some failed pods. Understand the difference between readiness and liveness probes and when to apply them for your app.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 KubernetesDefine a liveness commandMany applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations.In this exercise, you create a Pod that runs a container based on the registry.k8s.i


Question: When would you use Configure Liveness, Readiness and Startup Probes?

Answer: Configure Liveness, Readiness and Startup ProbesThis page shows how to configure liveness, readiness and startup probes for containers.For more information about probes, see Liveness, Readiness and Startup ProbesThe kubelet uses liveness probes to know when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress. Restarting a container in such a state can help to make the application more available despite bugs.A common pattern for liveness probes is to use the same low-cost HTTP endpoint as for readiness probes, but with a higher failureThreshold. This ensures that the pod is observed as not-ready for some period of time before it is hard killed.The kubelet uses readiness probes to know when a container is ready to start accepting traffic. One use of this signal is to control which Pods are used as backends for Services. A Pod is considered ready when its Ready condition is true. When a Pod is not ready, it is removed from Service load balancers. A Pod's Ready condition is false when its Node's Ready condition is not true, when one of the Pod's readinessGates is false, or when at least one of its containers is not ready.The kubelet uses startup probes to know when a container application has started. If such a probe is configured, liveness and readiness probes do not start until it succeeds, making sure those probes don't interfere with the application startup. This can be used to adopt liveness checks on slow starting containers, avoiding them getting killed by the kubelet before they are up and running.Caution:Liveness probes can be a powerful way to recover from application failures, but they should be used with caution. Liveness probes must be configured carefully to ensure that they truly indicate unrecoverable application failure, for example a deadlock.Note:Incorrect implementation of liveness probes can lead to cascading failures. This results in restarting of container under high load; failed client requests as your application became less scalable; and increased workload on remaining pods due to some failed pods. Understand the difference between readiness and liveness probes and when to apply them for your app.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 KubernetesDefine a liveness commandMany applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations.In this exercise, you create a Pod that runs a container based on the registry.k8s.i


Question: What are the benefits of Configure Liveness, Readiness and Startup Probes?

Answer: Configure Liveness, Readiness and Startup ProbesThis page shows how to configure liveness, readiness and startup probes for containers.For more information about probes, see Liveness, Readiness and Startup ProbesThe kubelet uses liveness probes to know when to restart a container. For example, liveness probes could catch a deadlock, where an application is running, but unable to make progress. Restarting a container in such a state can help to make the application more available despite bugs.A common pattern for liveness probes is to use the same low-cost HTTP endpoint as for readiness probes, but with a higher failureThreshold. This ensures that the pod is observed as not-ready for some period of time before it is hard killed.The kubelet uses readiness probes to know when a container is ready to start accepting traffic. One use of this signal is to control which Pods are used as backends for Services. A Pod is considered ready when its Ready condition is true. When a Pod is not ready, it is removed from Service load balancers. A Pod's Ready condition is false when its Node's Ready condition is not true, when one of the Pod's readinessGates is false, or when at least one of its containers is not ready.The kubelet uses startup probes to know when a container application has started. If such a probe is configured, liveness and readiness probes do not start until it succeeds, making sure those probes don't interfere with the application startup. This can be used to adopt liveness checks on slow starting containers, avoiding them getting killed by the kubelet before they are up and running.Caution:Liveness probes can be a powerful way to recover from application failures, but they should be used with caution. Liveness probes must be configured carefully to ensure that they truly indicate unrecoverable application failure, for example a deadlock.Note:Incorrect implementation of liveness probes can lead to cascading failures. This results in restarting of container under high load; failed client requests as your application became less scalable; and increased workload on remaining pods due to some failed pods. Understand the difference between readiness and liveness probes and when to apply them for your app.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 KubernetesDefine a liveness commandMany applications running for long periods of time eventually transition to broken states, and cannot recover except by being restarted. Kubernetes provides liveness probes to detect and remedy such situations.In this exercise, you create a Pod that runs a container based on the registry.k8s.i


Question: What is Configure Liveness, Readiness and Startup Probes?

Answer: T h i s   p a g e   s h o w s   h o w   t o   c o n f i g u r e   l i v e n e s s ,   r e a d i n e s s   a n d   s t a r t u p   p r o b e s   f o r   c o n t a i n e r s .   F o r   m o r e   i n f o r m a t i o n   a b o u t   p r o b e s ,   s e e   L i v e n e s s ,   R e a d i n e s s   a n d   S t a r t u p   P r o b e s   T h e   k u b e l e t   u s e s   l i v e n e s s   p r o b e s   t o   k n o w   w h e n   t o   r e s t a r t   a   c o n t a i n e r .   F o r   e x a m p l e ,   l i v e n e s s   p r o b e s   c o u l d   c a t c h   a   d e a d l o c k ,   w h e r e   a n   a p p l i c a t i o n   i s   r u n n i n g ,   b u t   u n a b l e   t o   m a k e   p r o g r e s s .   R e s t a r t i n g   a   c o n t a i n e r   i n   s u c h   a   s t a t e   c a n   h e l p   t o   m a k e   t h e   a p p l i c a t i o n   m o r e   a v a i l a b l e   d e s p i t e   b u g s .   A   c o m m o n   p a t t e r n   f o r   l i v e n e s s   p r o b e s   i s   t o   u s e   t h e   s a m e   l o w - c o s t   H T T P   e n d p o i n t   a s   f o r   r e a d i n e s s   p r o b e s ,   b u t   w i t h   a   h i g h e r   f a i l u r e T h r e s h o l d .   T h i s   e n s u r e s   t h a t   t h e   p o d   i s   o b s e r v e d   a s   n o t - r e a d y   f o r   s o m e   p e r i o d   o f   t i m e   b e f o r e   i t   i s   h a r d   k i l l e d .   T h e   k u b e l e t   u s e s   r e a d i n e s s   p r o b e s   t o   k n o w   w h e n   a   c o n t a i n e r   i s   r e a d y   t o   s t a r t   a c c e p t i n g   t r a f f i c .   O n e   u s e   o f   t h i s   s i g n a l   i s   t o   c o n t r o l   w h i c h   P o d s   a r e   u s e d   a s   b a c k e n d s   f o r   S e r v i c e s .   A   P o d   i s   c o n s i d e r e d   r e a d y   w h e n   i t s   R e a d y   c o n d i t i o n   i s   t r u e .   W h e n   a   P o d   i s   n o t   r e a d y ,   i t   i s   r e m o v e d   f r o m   S e r v i c e   l o a d   b a l a n c e r s .


Question: What is Before you begin?

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


Question: What is Define a liveness command?

Answer: M a n y   a p p l i c a t i o n s   r u n n i n g   f o r   l o n g   p e r i o d s   o f   t i m e   e v e n t u a l l y   t r a n s i t i o n   t o   b r o k e n   s t a t e s ,   a n d   c a n n o t   r e c o v e r   e x c e p t   b y   b e i n g   r e s t a r t e d .   K u b e r n e t e s   p r o v i d e s   l i v e n e s s   p r o b e s   t o   d e t e c t   a n d   r e m e d y   s u c h   s i t u a t i o n s .   I n   t h i s   e x e r c i s e ,   y o u   c r e a t e   a   P o d   t h a t   r u n s   a   c o n t a i n e r   b a s e d   o n   t h e   r e g i s t r y . k 8 s . i o / b u s y b o x : 1 . 2 7 . 2   i m a g e .   H e r e   i s   t h e   c o n f i g u r a t i o n   f i l e   f o r   t h e   P o d :   a p i V e r s i o n :   v 1   k i n d :   P o d   m e t a d a t a :   l a b e l s :   t e s t :   l i v e n e s s   n a m e :   l i v e n e s s - e x e c   s p e c :   c o n t a i n e r s :   -   n a m e :   l i v e n e s s   i m a g e :   r e g i s t r y . k 8 s . i o / b u s y b o x : 1 . 2 7 . 2   a r g s :   -   / b i n / s h   -   - c   -   t o u c h   / t m p / h e a l t h y ;   s l e e p   3 0 ;   r m   - f   / t m p / h e a l t h y ;   s l e e p   6 0 0   l i v e n e s s P r o b e :   e x e c :   c o m m a n d :   -   c a t   -   / t m p / h e a l t h y   i n i t i a l D e l a y S e c o n d s :   5   p e r i o d S e c o n d s :   5   I n   t h e   c o n f i g u r a t i o n   f i l e ,   y o u   c a n   s e e   t h a t   t h e   P o d   h a s   a   s i n g l e   C o n t a i n e r .   T h e   p e r i o d S e c o n d s   f i e l d   s p e c i f i e s   t h a t   t h e   k u b e l e t   s h o u l d   p e r f o r m   a   l i v e n e s s   p r o b e   e v e r y   5   s e c o n d s .   T h e   i n i t i a l D e l a y S e c o n d s   f i e l d   t e l l s   t h e   k u b e l e t   t h a t   i t   s h o u l d   w a i t   5   s e c o n d s   b e f o r e   p e r f o r m i n g   t h e   f i r s t   p r o b e .   T o   p e r f o r m   a   p r o b e ,   t h e