Question: When would you use Migrate Replicated Control Plane To Use Cloud Controller Manager?

Answer: Migrate Replicated Control Plane To Use Cloud Controller ManagerThe cloud-controller-manager is a Kubernetes control plane component that embeds cloud-specific control logic. The cloud controller manager lets you link your cluster into your cloud provider's API, and separates out the components that interact with that cloud platform from components that only interact with your cluster.By decoupling the interoperability logic between Kubernetes and the underlying cloud infrastructure, the cloud-controller-manager component enables cloud providers to release features at a different pace compared to the main Kubernetes project.BackgroundAs part of the cloud provider extraction effort, all cloud specific controllers must be moved out of the kube-controller-manager. All existing clusters that run cloud controllers in the kube-controller-manager must migrate to instead run the controllers in a cloud provider specific cloud-controller-manager.Leader Migration provides a mechanism in which HA clusters can safely migrate "cloud specific" controllers between the kube-controller-manager and the cloud-controller-manager via a shared resource lock between the two components while upgrading the replicated control plane. For a single-node control plane, or if unavailability of controller managers can be tolerated during the upgrade, Leader Migration is not needed and this guide can be ignored.Leader Migration can be enabled by setting --enable-leader-migration on kube-controller-manager or cloud-controller-manager. Leader Migration only applies during the upgrade and can be safely disabled or left enabled after the upgrade is complete.This guide walks you through the manual process of upgrading the control plane from kube-controller-manager with built-in cloud provider to running both kube-controller-manager and cloud-controller-manager. If you use a tool to deploy and manage the cluster, please refer to the documentation of the tool and the cloud provider for specific instructions of the migration.Before you beginIt is assumed that the control plane is running Kubernetes version N and to be upgraded to version N + 1. Although it is possible to migrate within the same version, ideally the migration should be performed as part of an upgrade so that changes of configuration can be aligned to each release. The exact versions of N and N + 1 depend on each cloud provider. For example, if a cloud provider builds a cloud-controller-manager to work with Kubernetes 1.24, then N can be 1.23 and N + 1 can be 1.24.The control plane nodes should run kube-controller-manager with Leader Election enabled, which is the default. As of version N, an in-tree cloud provider must be set with --cloud-provider flag and cloud-controller-manager should not yet be deployed.The out-of-tree cloud provider must have built a cloud-controller-manager with Leader Migration implementation. If the cloud provider imports k8s.io/cloud-provider and k8s.io/controller-manager of version v0.21.0 or la


Question: What are the benefits of Migrate Replicated Control Plane To Use Cloud Controller Manager?

Answer: Migrate Replicated Control Plane To Use Cloud Controller ManagerThe cloud-controller-manager is a Kubernetes control plane component that embeds cloud-specific control logic. The cloud controller manager lets you link your cluster into your cloud provider's API, and separates out the components that interact with that cloud platform from components that only interact with your cluster.By decoupling the interoperability logic between Kubernetes and the underlying cloud infrastructure, the cloud-controller-manager component enables cloud providers to release features at a different pace compared to the main Kubernetes project.BackgroundAs part of the cloud provider extraction effort, all cloud specific controllers must be moved out of the kube-controller-manager. All existing clusters that run cloud controllers in the kube-controller-manager must migrate to instead run the controllers in a cloud provider specific cloud-controller-manager.Leader Migration provides a mechanism in which HA clusters can safely migrate "cloud specific" controllers between the kube-controller-manager and the cloud-controller-manager via a shared resource lock between the two components while upgrading the replicated control plane. For a single-node control plane, or if unavailability of controller managers can be tolerated during the upgrade, Leader Migration is not needed and this guide can be ignored.Leader Migration can be enabled by setting --enable-leader-migration on kube-controller-manager or cloud-controller-manager. Leader Migration only applies during the upgrade and can be safely disabled or left enabled after the upgrade is complete.This guide walks you through the manual process of upgrading the control plane from kube-controller-manager with built-in cloud provider to running both kube-controller-manager and cloud-controller-manager. If you use a tool to deploy and manage the cluster, please refer to the documentation of the tool and the cloud provider for specific instructions of the migration.Before you beginIt is assumed that the control plane is running Kubernetes version N and to be upgraded to version N + 1. Although it is possible to migrate within the same version, ideally the migration should be performed as part of an upgrade so that changes of configuration can be aligned to each release. The exact versions of N and N + 1 depend on each cloud provider. For example, if a cloud provider builds a cloud-controller-manager to work with Kubernetes 1.24, then N can be 1.23 and N + 1 can be 1.24.The control plane nodes should run kube-controller-manager with Leader Election enabled, which is the default. As of version N, an in-tree cloud provider must be set with --cloud-provider flag and cloud-controller-manager should not yet be deployed.The out-of-tree cloud provider must have built a cloud-controller-manager with Leader Migration implementation. If the cloud provider imports k8s.io/cloud-provider and k8s.io/controller-manager of version v0.21.0 or la


Question: What is Migrate Replicated Control Plane To Use Cloud Controller Manager?

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


Question: What is Background?

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


Question: What is Before you begin?

Answer: I t   i s   a s s u m e d   t h a t   t h e   c o n t r o l   p l a n e   i s   r u n n i n g   K u b e r n e t e s   v e r s i o n   N   a n d   t o   b e   u p g r a d e d   t o   v e r s i o n   N   +   1 .   A l t h o u g h   i t   i s   p o s s i b l e   t o   m i g r a t e   w i t h i n   t h e   s a m e   v e r s i o n ,   i d e a l l y   t h e   m i g r a t i o n   s h o u l d   b e   p e r f o r m e d   a s   p a r t   o f   a n   u p g r a d e   s o   t h a t   c h a n g e s   o f   c o n f i g u r a t i o n   c a n   b e   a l i g n e d   t o   e a c h   r e l e a s e .   T h e   e x a c t   v e r s i o n s   o f   N   a n d   N   +   1   d e p e n d   o n   e a c h   c l o u d   p r o v i d e r .   F o r   e x a m p l e ,   i f   a   c l o u d   p r o v i d e r   b u i l d s   a   c l o u d - c o n t r o l l e r - m a n a g e r   t o   w o r k   w i t h   K u b e r n e t e s   1 . 2 4 ,   t h e n   N   c a n   b e   1 . 2 3   a n d   N   +   1   c a n   b e   1 . 2 4 .   T h e   c o n t r o l   p l a n e   n o d e s   s h o u l d   r u n   k u b e - c o n t r o l l e r - m a n a g e r   w i t h   L e a d e r   E l e c t i o n   e n a b l e d ,   w h i c h   i s   t h e   d e f a u l t .   A s   o f   v e r s i o n   N ,   a n   i n - t r e e   c l o u d   p r o v i d e r   m u s t   b e   s e t   w i t h   - - c l o u d - p r o v i d e r   f l a g   a n d   c l o u d - c o n t r o l l e r - m a n a g e r   s h o u l d   n o t   y e t   b e   d e p l o y e d .   T h e   o u t - o f - t r e e   c l o u d   p r o v i d e r   m u s t   h a v e   b u i l t   a   c l o u d - c o n t r o l l e r - m a n a g e r   w i t h   L e a d e r   M i g r a t i o n   i m p l e m e n t a t i o n .   I f   t h e   c l o u d   p r o v i d e r   i m p o r t s   k 8 s . i o / c l o u d - p r o v i d e r   a n d   k 8 s . i o / c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   v 0 . 2 1 . 0   o r   l a t e r ,   L e a d e r   M i g r a t i o n   w i l l   b e   a v a


Question: What is Grant access to Migration Lease?

Answer: T h e   d e f a u l t   p e r m i s s i o n s   o f   t h e   c o n t r o l l e r   m a n a g e r   a l l o w   o n l y   a c c e s s e s   t o   t h e i r   m a i n   L e a s e .   I n   o r d e r   f o r   t h e   m i g r a t i o n   t o   w o r k ,   a c c e s s e s   t o   a n o t h e r   L e a s e   a r e   r e q u i r e d .   Y o u   c a n   g r a n t   k u b e - c o n t r o l l e r - m a n a g e r   f u l l   a c c e s s   t o   t h e   l e a s e s   A P I   b y   m o d i f y i n g   t h e   s y s t e m : : l e a d e r - l o c k i n g - k u b e - c o n t r o l l e r - m a n a g e r   r o l e .   T h i s   t a s k   g u i d e   a s s u m e s   t h a t   t h e   n a m e   o f   t h e   m i g r a t i o n   l e a s e   i s   c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n .   k u b e c t l   p a t c h   - n   k u b e - s y s t e m   r o l e   ' s y s t e m : : l e a d e r - l o c k i n g - k u b e - c o n t r o l l e r - m a n a g e r '   - p   ' { " r u l e s " :   [   { " a p i G r o u p s " : [   " c o o r d i n a t i o n . k 8 s . i o " ] ,   " r e s o u r c e s " :   [ " l e a s e s " ] ,   " r e s o u r c e N a m e s " :   [ " c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n " ] ,   " v e r b s " :   [ " c r e a t e " ,   " l i s t " ,   " g e t " ,   " u p d a t e " ]   }   ] } '   - - t y p e = m e r g e `   D o   t h e   s a m e   t o   t h e   s y s t e m : : l e a d e r - l o c k i n g - c l o u d - c o n t r o l l e r - m a n a g e r   r o l e .   k u b e c t l   p a t c h   - n   k u b e - s y s t e m   r o l e   ' s y s t e m : : l e a d e r - l o c k i n g - c l o u d - c o n t r o l l e r - m a n a g e r '   - p   ' { " r u l e s " :   [   { " a p i G r o u p s " : [   " c o o r d i n a t i o n . k 8 s . i o " ] ,   " r e s o u r c e s " :   [ " l e a s e s " ] ,   " r e s o u r c e N a m e s " :   [ " c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n " ] ,   " v e r b s " :   [ " c r


Question: What is Initial Leader Migration configuration?

Answer: L e a d e r   M i g r a t i o n   o p t i o n a l l y   t a k e s   a   c o n f i g u r a t i o n   f i l e   r e p r e s e n t i n g   t h e   s t a t e   o f   c o n t r o l l e r - t o - m a n a g e r   a s s i g n m e n t .   A t   t h i s   m o m e n t ,   w i t h   i n - t r e e   c l o u d   p r o v i d e r ,   k u b e - c o n t r o l l e r - m a n a g e r   r u n s   r o u t e ,   s e r v i c e ,   a n d   c l o u d - n o d e - l i f e c y c l e .   T h e   f o l l o w i n g   e x a m p l e   c o n f i g u r a t i o n   s h o w s   t h e   a s s i g n m e n t .   L e a d e r   M i g r a t i o n   c a n   b e   e n a b l e d   w i t h o u t   a   c o n f i g u r a t i o n .   P l e a s e   s e e   D e f a u l t   C o n f i g u r a t i o n   f o r   d e t a i l s .   k i n d :   L e a d e r M i g r a t i o n C o n f i g u r a t i o n   a p i V e r s i o n :   c o n t r o l l e r m a n a g e r . c o n f i g . k 8 s . i o / v 1   l e a d e r N a m e :   c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n   r e s o u r c e L o c k :   l e a s e s   c o n t r o l l e r L e a d e r s :   -   n a m e :   r o u t e   c o m p o n e n t :   k u b e - c o n t r o l l e r - m a n a g e r   -   n a m e :   s e r v i c e   c o m p o n e n t :   k u b e - c o n t r o l l e r - m a n a g e r   -   n a m e :   c l o u d - n o d e - l i f e c y c l e   c o m p o n e n t :   k u b e - c o n t r o l l e r - m a n a g e r   A l t e r n a t i v e l y ,   b e c a u s e   t h e   c o n t r o l l e r s   c a n   r u n   u n d e r   e i t h e r   c o n t r o l l e r   m a n a g e r s ,   s e t t i n g   c o m p o n e n t   t o   *   f o r   b o t h   s i d e s   m a k e s   t h e   c o n f i g u r a t i o n   f i l e   c o n s i s t e n t   b e t w e e n   b o t h   p a r t i e s   o f   t h e   m i g r a t i o n .   #   w i l d c a r d   v e r s i o n   k i n d :   L e a d e r M i g r a t i o n C o n f i g u r a t i o n   a p i V e r s i o n :   c o n t r o l l e r


Question: What is Deploy Cloud Controller Manager?

Answer: I n   v e r s i o n   N   +   1 ,   t h e   d e s i r e d   s t a t e   o f   c o n t r o l l e r - t o - m a n a g e r   a s s i g n m e n t   c a n   b e   r e p r e s e n t e d   b y   a   n e w   c o n f i g u r a t i o n   f i l e ,   s h o w n   a s   f o l l o w s .   P l e a s e   n o t e   c o m p o n e n t   f i e l d   o f   e a c h   c o n t r o l l e r L e a d e r s   c h a n g i n g   f r o m   k u b e - c o n t r o l l e r - m a n a g e r   t o   c l o u d - c o n t r o l l e r - m a n a g e r .   A l t e r n a t i v e l y ,   u s e   t h e   w i l d c a r d   v e r s i o n   m e n t i o n e d   a b o v e ,   w h i c h   h a s   t h e   s a m e   e f f e c t .   k i n d :   L e a d e r M i g r a t i o n C o n f i g u r a t i o n   a p i V e r s i o n :   c o n t r o l l e r m a n a g e r . c o n f i g . k 8 s . i o / v 1   l e a d e r N a m e :   c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n   r e s o u r c e L o c k :   l e a s e s   c o n t r o l l e r L e a d e r s :   -   n a m e :   r o u t e   c o m p o n e n t :   c l o u d - c o n t r o l l e r - m a n a g e r   -   n a m e :   s e r v i c e   c o m p o n e n t :   c l o u d - c o n t r o l l e r - m a n a g e r   -   n a m e :   c l o u d - n o d e - l i f e c y c l e   c o m p o n e n t :   c l o u d - c o n t r o l l e r - m a n a g e r   W h e n   c r e a t i n g   c o n t r o l   p l a n e   n o d e s   o f   v e r s i o n   N   +   1 ,   t h e   c o n t e n t   s h o u l d   b e   d e p l o y e d   t o   / e t c / l e a d e r m i g r a t i o n . c o n f .   T h e   m a n i f e s t   o f   c l o u d - c o n t r o l l e r - m a n a g e r   s h o u l d   b e   u p d a t e d   t o   m o u n t   t h e   c o n f i g u r a t i o n   f i l e   i n   t h e   s a m e   m a n n e r   a s   k u b e - c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   N .   S i m i l a r l y ,   a d d   - - e n a b l e - l e a d e r - m i g r a t i o n   a n d   - - l e a d e r - m i


Question: What is Upgrade Control Plane?

Answer: T h e   c o n t r o l   p l a n e   n o w   c o n t a i n s   n o d e s   o f   b o t h   v e r s i o n   N   a n d   N   +   1 .   T h e   n o d e s   o f   v e r s i o n   N   r u n   k u b e - c o n t r o l l e r - m a n a g e r   o n l y ,   a n d   t h e s e   o f   v e r s i o n   N   +   1   r u n   b o t h   k u b e - c o n t r o l l e r - m a n a g e r   a n d   c l o u d - c o n t r o l l e r - m a n a g e r .   T h e   m i g r a t e d   c o n t r o l l e r s ,   a s   s p e c i f i e d   i n   t h e   c o n f i g u r a t i o n ,   a r e   r u n n i n g   u n d e r   e i t h e r   k u b e - c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   N   o r   c l o u d - c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   N   +   1   d e p e n d i n g   o n   w h i c h   c o n t r o l l e r   m a n a g e r   h o l d s   t h e   m i g r a t i o n   l e a s e .   N o   c o n t r o l l e r   w i l l   e v e r   b e   r u n n i n g   u n d e r   b o t h   c o n t r o l l e r   m a n a g e r s   a t   a n y   t i m e .   I n   a   r o l l i n g   m a n n e r ,   c r e a t e   a   n e w   c o n t r o l   p l a n e   n o d e   o f   v e r s i o n   N   +   1   a n d   b r i n g   d o w n   o n e   o f   v e r s i o n   N   u n t i l   t h e   c o n t r o l   p l a n e   c o n t a i n s   o n l y   n o d e s   o f   v e r s i o n   N   +   1 .   I f   a   r o l l b a c k   f r o m   v e r s i o n   N   +   1   t o   N   i s   r e q u i r e d ,   a d d   n o d e s   o f   v e r s i o n   N   w i t h   L e a d e r   M i g r a t i o n   e n a b l e d   f o r   k u b e - c o n t r o l l e r - m a n a g e r   b a c k   t o   t h e   c o n t r o l   p l a n e ,   r e p l a c i n g   o n e   o f   v e r s i o n   N   +   1   e a c h   t i m e   u n t i l   t h e r e   a r e   o n l y   n o d e s   o f   v e r s i o n   N .


Question: What is (Optional) Disable Leader Migration?

Answer: N o w   t h a t   t h e   c o n t r o l   p l a n e   h a s   b e e n   u p g r a d e d   t o   r u n   b o t h   k u b e - c o n t r o l l e r - m a n a g e r   a n d   c l o u d - c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   N   +   1 ,   L e a d e r   M i g r a t i o n   h a s   f i n i s h e d   i t s   j o b   a n d   c a n   b e   s a f e l y   d i s a b l e d   t o   s a v e   o n e   L e a s e   r e s o u r c e .   I t   i s   s a f e   t o   r e - e n a b l e   L e a d e r   M i g r a t i o n   f o r   t h e   r o l l b a c k   i n   t h e   f u t u r e .   I n   a   r o l l i n g   m a n a g e r ,   u p d a t e   m a n i f e s t   o f   c l o u d - c o n t r o l l e r - m a n a g e r   t o   u n s e t   b o t h   - - e n a b l e - l e a d e r - m i g r a t i o n   a n d   - - l e a d e r - m i g r a t i o n - c o n f i g =   f l a g ,   a l s o   r e m o v e   t h e   m o u n t   o f   / e t c / l e a d e r m i g r a t i o n . c o n f ,   a n d   f i n a l l y   r e m o v e   / e t c / l e a d e r m i g r a t i o n . c o n f .   T o   r e - e n a b l e   L e a d e r   M i g r a t i o n ,   r e c r e a t e   t h e   c o n f i g u r a t i o n   f i l e   a n d   a d d   i t s   m o u n t   a n d   t h e   f l a g s   t h a t   e n a b l e   L e a d e r   M i g r a t i o n   b a c k   t o   c l o u d - c o n t r o l l e r - m a n a g e r .


Question: What is Default Configuration?

Answer: S t a r t i n g   K u b e r n e t e s   1 . 2 2 ,   L e a d e r   M i g r a t i o n   p r o v i d e s   a   d e f a u l t   c o n f i g u r a t i o n   s u i t a b l e   f o r   t h e   d e f a u l t   c o n t r o l l e r - t o - m a n a g e r   a s s i g n m e n t .   T h e   d e f a u l t   c o n f i g u r a t i o n   c a n   b e   e n a b l e d   b y   s e t t i n g   - - e n a b l e - l e a d e r - m i g r a t i o n   b u t   w i t h o u t   - - l e a d e r - m i g r a t i o n - c o n f i g = .   F o r   k u b e - c o n t r o l l e r - m a n a g e r   a n d   c l o u d - c o n t r o l l e r - m a n a g e r ,   i f   t h e r e   a r e   n o   f l a g s   t h a t   e n a b l e   a n y   i n - t r e e   c l o u d   p r o v i d e r   o r   c h a n g e   o w n e r s h i p   o f   c o n t r o l l e r s ,   t h e   d e f a u l t   c o n f i g u r a t i o n   c a n   b e   u s e d   t o   a v o i d   m a n u a l   c r e a t i o n   o f   t h e   c o n f i g u r a t i o n   f i l e .


Question: What is Special case: migrating the Node IPAM controller?

Answer: I f   y o u r   c l o u d   p r o v i d e r   p r o v i d e s   a n   i m p l e m e n t a t i o n   o f   N o d e   I P A M   c o n t r o l l e r ,   y o u   s h o u l d   s w i t c h   t o   t h e   i m p l e m e n t a t i o n   i n   c l o u d - c o n t r o l l e r - m a n a g e r .   D i s a b l e   N o d e   I P A M   c o n t r o l l e r   i n   k u b e - c o n t r o l l e r - m a n a g e r   o f   v e r s i o n   N   +   1   b y   a d d i n g   - - c o n t r o l l e r s = * , - n o d e i p a m   t o   i t s   f l a g s .   T h e n   a d d   n o d e i p a m   t o   t h e   l i s t   o f   m i g r a t e d   c o n t r o l l e r s .   #   w i l d c a r d   v e r s i o n ,   w i t h   n o d e i p a m   k i n d :   L e a d e r M i g r a t i o n C o n f i g u r a t i o n   a p i V e r s i o n :   c o n t r o l l e r m a n a g e r . c o n f i g . k 8 s . i o / v 1   l e a d e r N a m e :   c l o u d - p r o v i d e r - e x t r a c t i o n - m i g r a t i o n   r e s o u r c e L o c k :   l e a s e s   c o n t r o l l e r L e a d e r s :   -   n a m e :   r o u t e   c o m p o n e n t :   *   -   n a m e :   s e r v i c e   c o m p o n e n t :   *   -   n a m e :   c l o u d - n o d e - l i f e c y c l e   c o m p o n e n t :   *   -   n a m e :   n o d e i p a m   -   c o m p o n e n t :   *


Question: What is What's next?

Answer: R e a d   t h e   C o n t r o l l e r   M a n a g e r   L e a d e r   M i g r a t i o n   e n h a n c e m e n t   p r o p o s a l .


Question: What is Client Libraries?

Answer: Client LibrariesThis page contains an overview of the client libraries for using the Kubernetes API from various programming languages.To write applications using the Kubernetes REST API, you do not need to implement the API calls and request/response types yourself. You can use a client library for the programming language you are using.Client libraries often handle common tasks such as authentication for you. Most client libraries can discover and use the Kubernetes Service Account to authenticate if the API client is running inside the Kubernetes cluster, or can understand the kubeconfig file format to read the credentials and the API Server address.Officially-supported Kubernetes client librariesThe following client libraries are officially maintained by Kubernetes SIG API Machinery.LanguageClient LibrarySample ProgramsCgithub.com/kubernetes-client/cbrowsedotnetgithub.com/kubernetes-client/csharpbrowseGogithub.com/kubernetes/client-go/browseHaskellgithub.com/kubernetes-client/haskellbrowseJavagithub.com/kubernetes-client/javabrowseJavaScriptgithub.com/kubernetes-client/javascriptbrowsePerlgithub.com/kubernetes-client/perl/browsePythongithub.com/kubernetes-client/python/browseRubygithub.com/kubernetes-client/ruby/browseCommunity-maintained client librariesNote: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.The following Kubernetes API client libraries are provided and maintained by their authors, not the Kubernetes team.LanguageClient LibraryClojuregithub.com/yanatan16/clj-kubernetes-apiDotNetgithub.com/tonnyeremin/kubernetes_genDotNet (RestSharp)github.com/masroorhasan/Kubernetes.DotNetElixirgithub.com/obmarg/kazanElixirgithub.com/coryodaniel/k8sJava (OSGi)bitbucket.org/amdatulabs/amdatu-kubernetesJava (Fabric8, OSGi)github.com/fabric8io/kubernetes-clientJavagithub.com/manusa/yakcLispgithub.com/brendandburns/cl-k8sLispgithub.com/xh4/cubeNode.js (TypeScript)github.com/Goyoo/node-k8s-clientNode.jsgithub.com/ajpauwels/easy-k8sNode.jsgithub.com/godaddy/kubernetes-clientNode.jsgithub.com/tenxcloud/node-kubernetes-clientPerlmetacpan.org/pod/Net::KubernetesPHPgithub.com/allansun/kubernetes-php-clientPHPgithub.com/maclof/kubernetes-clientPHPgithub.com/travisghansen/kubernetes-client-phpPHPgithub.com/renoki-co/php-k8sPythongithub.com/cloudcoil/cloudcoilPythongithub.com/fiaas/k8sPythongithub.com/gtsystem/lightkubePythongithub.com/kr8s-org/kr8sPythongithub.com/mnubo/kubernetes-pyPythongithub.com/tomplus/kubernetes_asyncioPythongithub.com/Frankkkkk/pykormRubygithub.com/abonas/kubeclientRubygithub.com/k8s-ruby/k8s-rubyRubygithub.com/kontena/k8s-clientRustgithub.com/kube-rs/kubeRustgithub.com/ynqa/kubernetes-rustScalagithub.com/hagay3/skuberScalagithub.com/hnaderi/scala-k8sScalagithub.com/joan38/kubernetes-clie


Question: How does Client Libraries work?

Answer: Client LibrariesThis page contains an overview of the client libraries for using the Kubernetes API from various programming languages.To write applications using the Kubernetes REST API, you do not need to implement the API calls and request/response types yourself. You can use a client library for the programming language you are using.Client libraries often handle common tasks such as authentication for you. Most client libraries can discover and use the Kubernetes Service Account to authenticate if the API client is running inside the Kubernetes cluster, or can understand the kubeconfig file format to read the credentials and the API Server address.Officially-supported Kubernetes client librariesThe following client libraries are officially maintained by Kubernetes SIG API Machinery.LanguageClient LibrarySample ProgramsCgithub.com/kubernetes-client/cbrowsedotnetgithub.com/kubernetes-client/csharpbrowseGogithub.com/kubernetes/client-go/browseHaskellgithub.com/kubernetes-client/haskellbrowseJavagithub.com/kubernetes-client/javabrowseJavaScriptgithub.com/kubernetes-client/javascriptbrowsePerlgithub.com/kubernetes-client/perl/browsePythongithub.com/kubernetes-client/python/browseRubygithub.com/kubernetes-client/ruby/browseCommunity-maintained client librariesNote: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.The following Kubernetes API client libraries are provided and maintained by their authors, not the Kubernetes team.LanguageClient LibraryClojuregithub.com/yanatan16/clj-kubernetes-apiDotNetgithub.com/tonnyeremin/kubernetes_genDotNet (RestSharp)github.com/masroorhasan/Kubernetes.DotNetElixirgithub.com/obmarg/kazanElixirgithub.com/coryodaniel/k8sJava (OSGi)bitbucket.org/amdatulabs/amdatu-kubernetesJava (Fabric8, OSGi)github.com/fabric8io/kubernetes-clientJavagithub.com/manusa/yakcLispgithub.com/brendandburns/cl-k8sLispgithub.com/xh4/cubeNode.js (TypeScript)github.com/Goyoo/node-k8s-clientNode.jsgithub.com/ajpauwels/easy-k8sNode.jsgithub.com/godaddy/kubernetes-clientNode.jsgithub.com/tenxcloud/node-kubernetes-clientPerlmetacpan.org/pod/Net::KubernetesPHPgithub.com/allansun/kubernetes-php-clientPHPgithub.com/maclof/kubernetes-clientPHPgithub.com/travisghansen/kubernetes-client-phpPHPgithub.com/renoki-co/php-k8sPythongithub.com/cloudcoil/cloudcoilPythongithub.com/fiaas/k8sPythongithub.com/gtsystem/lightkubePythongithub.com/kr8s-org/kr8sPythongithub.com/mnubo/kubernetes-pyPythongithub.com/tomplus/kubernetes_asyncioPythongithub.com/Frankkkkk/pykormRubygithub.com/abonas/kubeclientRubygithub.com/k8s-ruby/k8s-rubyRubygithub.com/kontena/k8s-clientRustgithub.com/kube-rs/kubeRustgithub.com/ynqa/kubernetes-rustScalagithub.com/hagay3/skuberScalagithub.com/hnaderi/scala-k8sScalagithub.com/joan38/kubernetes-clie


Question: When would you use Client Libraries?

Answer: Client LibrariesThis page contains an overview of the client libraries for using the Kubernetes API from various programming languages.To write applications using the Kubernetes REST API, you do not need to implement the API calls and request/response types yourself. You can use a client library for the programming language you are using.Client libraries often handle common tasks such as authentication for you. Most client libraries can discover and use the Kubernetes Service Account to authenticate if the API client is running inside the Kubernetes cluster, or can understand the kubeconfig file format to read the credentials and the API Server address.Officially-supported Kubernetes client librariesThe following client libraries are officially maintained by Kubernetes SIG API Machinery.LanguageClient LibrarySample ProgramsCgithub.com/kubernetes-client/cbrowsedotnetgithub.com/kubernetes-client/csharpbrowseGogithub.com/kubernetes/client-go/browseHaskellgithub.com/kubernetes-client/haskellbrowseJavagithub.com/kubernetes-client/javabrowseJavaScriptgithub.com/kubernetes-client/javascriptbrowsePerlgithub.com/kubernetes-client/perl/browsePythongithub.com/kubernetes-client/python/browseRubygithub.com/kubernetes-client/ruby/browseCommunity-maintained client librariesNote: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.The following Kubernetes API client libraries are provided and maintained by their authors, not the Kubernetes team.LanguageClient LibraryClojuregithub.com/yanatan16/clj-kubernetes-apiDotNetgithub.com/tonnyeremin/kubernetes_genDotNet (RestSharp)github.com/masroorhasan/Kubernetes.DotNetElixirgithub.com/obmarg/kazanElixirgithub.com/coryodaniel/k8sJava (OSGi)bitbucket.org/amdatulabs/amdatu-kubernetesJava (Fabric8, OSGi)github.com/fabric8io/kubernetes-clientJavagithub.com/manusa/yakcLispgithub.com/brendandburns/cl-k8sLispgithub.com/xh4/cubeNode.js (TypeScript)github.com/Goyoo/node-k8s-clientNode.jsgithub.com/ajpauwels/easy-k8sNode.jsgithub.com/godaddy/kubernetes-clientNode.jsgithub.com/tenxcloud/node-kubernetes-clientPerlmetacpan.org/pod/Net::KubernetesPHPgithub.com/allansun/kubernetes-php-clientPHPgithub.com/maclof/kubernetes-clientPHPgithub.com/travisghansen/kubernetes-client-phpPHPgithub.com/renoki-co/php-k8sPythongithub.com/cloudcoil/cloudcoilPythongithub.com/fiaas/k8sPythongithub.com/gtsystem/lightkubePythongithub.com/kr8s-org/kr8sPythongithub.com/mnubo/kubernetes-pyPythongithub.com/tomplus/kubernetes_asyncioPythongithub.com/Frankkkkk/pykormRubygithub.com/abonas/kubeclientRubygithub.com/k8s-ruby/k8s-rubyRubygithub.com/kontena/k8s-clientRustgithub.com/kube-rs/kubeRustgithub.com/ynqa/kubernetes-rustScalagithub.com/hagay3/skuberScalagithub.com/hnaderi/scala-k8sScalagithub.com/joan38/kubernetes-clie


Question: What are the benefits of Client Libraries?

Answer: Client LibrariesThis page contains an overview of the client libraries for using the Kubernetes API from various programming languages.To write applications using the Kubernetes REST API, you do not need to implement the API calls and request/response types yourself. You can use a client library for the programming language you are using.Client libraries often handle common tasks such as authentication for you. Most client libraries can discover and use the Kubernetes Service Account to authenticate if the API client is running inside the Kubernetes cluster, or can understand the kubeconfig file format to read the credentials and the API Server address.Officially-supported Kubernetes client librariesThe following client libraries are officially maintained by Kubernetes SIG API Machinery.LanguageClient LibrarySample ProgramsCgithub.com/kubernetes-client/cbrowsedotnetgithub.com/kubernetes-client/csharpbrowseGogithub.com/kubernetes/client-go/browseHaskellgithub.com/kubernetes-client/haskellbrowseJavagithub.com/kubernetes-client/javabrowseJavaScriptgithub.com/kubernetes-client/javascriptbrowsePerlgithub.com/kubernetes-client/perl/browsePythongithub.com/kubernetes-client/python/browseRubygithub.com/kubernetes-client/ruby/browseCommunity-maintained client librariesNote: This section links to third party projects that provide functionality required by Kubernetes. The Kubernetes project authors aren't responsible for these projects, which are listed alphabetically. To add a project to this list, read the content guide before submitting a change. More information.The following Kubernetes API client libraries are provided and maintained by their authors, not the Kubernetes team.LanguageClient LibraryClojuregithub.com/yanatan16/clj-kubernetes-apiDotNetgithub.com/tonnyeremin/kubernetes_genDotNet (RestSharp)github.com/masroorhasan/Kubernetes.DotNetElixirgithub.com/obmarg/kazanElixirgithub.com/coryodaniel/k8sJava (OSGi)bitbucket.org/amdatulabs/amdatu-kubernetesJava (Fabric8, OSGi)github.com/fabric8io/kubernetes-clientJavagithub.com/manusa/yakcLispgithub.com/brendandburns/cl-k8sLispgithub.com/xh4/cubeNode.js (TypeScript)github.com/Goyoo/node-k8s-clientNode.jsgithub.com/ajpauwels/easy-k8sNode.jsgithub.com/godaddy/kubernetes-clientNode.jsgithub.com/tenxcloud/node-kubernetes-clientPerlmetacpan.org/pod/Net::KubernetesPHPgithub.com/allansun/kubernetes-php-clientPHPgithub.com/maclof/kubernetes-clientPHPgithub.com/travisghansen/kubernetes-client-phpPHPgithub.com/renoki-co/php-k8sPythongithub.com/cloudcoil/cloudcoilPythongithub.com/fiaas/k8sPythongithub.com/gtsystem/lightkubePythongithub.com/kr8s-org/kr8sPythongithub.com/mnubo/kubernetes-pyPythongithub.com/tomplus/kubernetes_asyncioPythongithub.com/Frankkkkk/pykormRubygithub.com/abonas/kubeclientRubygithub.com/k8s-ruby/k8s-rubyRubygithub.com/kontena/k8s-clientRustgithub.com/kube-rs/kubeRustgithub.com/ynqa/kubernetes-rustScalagithub.com/hagay3/skuberScalagithub.com/hnaderi/scala-k8sScalagithub.com/joan38/kubernetes-clie


Question: What is Client Libraries?

Answer: T h i s   p a g e   c o n t a i n s   a n   o v e r v i e w   o f   t h e   c l i e n t   l i b r a r i e s   f o r   u s i n g   t h e   K u b e r n e t e s   A P I   f r o m   v a r i o u s   p r o g r a m m i n g   l a n g u a g e s .   T o   w r i t e   a p p l i c a t i o n s   u s i n g   t h e   K u b e r n e t e s   R E S T   A P I ,   y o u   d o   n o t   n e e d   t o   i m p l e m e n t   t h e   A P I   c a l l s   a n d   r e q u e s t / r e s p o n s e   t y p e s   y o u r s e l f .   Y o u   c a n   u s e   a   c l i e n t   l i b r a r y   f o r   t h e   p r o g r a m m i n g   l a n g u a g e   y o u   a r e   u s i n g .   C l i e n t   l i b r a r i e s   o f t e n   h a n d l e   c o m m o n   t a s k s   s u c h   a s   a u t h e n t i c a t i o n   f o r   y o u .   M o s t   c l i e n t   l i b r a r i e s   c a n   d i s c o v e r   a n d   u s e   t h e   K u b e r n e t e s   S e r v i c e   A c c o u n t   t o   a u t h e n t i c a t e   i f   t h e   A P I   c l i e n t   i s   r u n n i n g   i n s i d e   t h e   K u b e r n e t e s   c l u s t e r ,   o r   c a n   u n d e r s t a n d   t h e   k u b e c o n f i g   f i l e   f o r m a t   t o   r e a d   t h e   c r e d e n t i a l s   a n d   t h e   A P I   S e r v e r   a d d r e s s .


Question: What is Officially-supported Kubernetes client libraries?

Answer: T h e   f o l l o w i n g   c l i e n t   l i b r a r i e s   a r e   o f f i c i a l l y   m a i n t a i n e d   b y   K u b e r n e t e s   S I G   A P I   M a c h i n e r y .


Question: What is Community-maintained client libraries?

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


Question: What is Instrumentation?

Answer: InstrumentationKubernetes Component SLI MetricsHigh-level indicators for measuring the reliability and performance of Kubernetes components.CRI Pod & Container MetricsCollection of Pod & Container metrics via the CRI.Node metrics dataMechanisms for accessing metrics at node, volume, pod and container level, as seen by the kubelet.Understand Pressure Stall Information (PSI) MetricsDetailed explanation of Pressure Stall Information (PSI) metrics and how to use them to identify resource pressure in Kubernetes.Kubernetes z-pagesProvides runtime diagnostics for Kubernetes components, offering insights into component runtime status and configuration flags.Kubernetes Metrics ReferenceDetails of the metric data that Kubernetes components export.


Question: How does Instrumentation work?

Answer: InstrumentationKubernetes Component SLI MetricsHigh-level indicators for measuring the reliability and performance of Kubernetes components.CRI Pod & Container MetricsCollection of Pod & Container metrics via the CRI.Node metrics dataMechanisms for accessing metrics at node, volume, pod and container level, as seen by the kubelet.Understand Pressure Stall Information (PSI) MetricsDetailed explanation of Pressure Stall Information (PSI) metrics and how to use them to identify resource pressure in Kubernetes.Kubernetes z-pagesProvides runtime diagnostics for Kubernetes components, offering insights into component runtime status and configuration flags.Kubernetes Metrics ReferenceDetails of the metric data that Kubernetes components export.


Question: When would you use Instrumentation?

Answer: InstrumentationKubernetes Component SLI MetricsHigh-level indicators for measuring the reliability and performance of Kubernetes components.CRI Pod & Container MetricsCollection of Pod & Container metrics via the CRI.Node metrics dataMechanisms for accessing metrics at node, volume, pod and container level, as seen by the kubelet.Understand Pressure Stall Information (PSI) MetricsDetailed explanation of Pressure Stall Information (PSI) metrics and how to use them to identify resource pressure in Kubernetes.Kubernetes z-pagesProvides runtime diagnostics for Kubernetes components, offering insights into component runtime status and configuration flags.Kubernetes Metrics ReferenceDetails of the metric data that Kubernetes components export.


Question: What are the benefits of Instrumentation?

Answer: InstrumentationKubernetes Component SLI MetricsHigh-level indicators for measuring the reliability and performance of Kubernetes components.CRI Pod & Container MetricsCollection of Pod & Container metrics via the CRI.Node metrics dataMechanisms for accessing metrics at node, volume, pod and container level, as seen by the kubelet.Understand Pressure Stall Information (PSI) MetricsDetailed explanation of Pressure Stall Information (PSI) metrics and how to use them to identify resource pressure in Kubernetes.Kubernetes z-pagesProvides runtime diagnostics for Kubernetes components, offering insights into component runtime status and configuration flags.Kubernetes Metrics ReferenceDetails of the metric data that Kubernetes components export.


Question: What is Kubernetes Component SLI Metrics?

Answer: H i g h - l e v e l   i n d i c a t o r s   f o r   m e a s u r i n g   t h e   r e l i a b i l i t y   a n d   p e r f o r m a n c e   o f   K u b e r n e t e s   c o m p o n e n t s .


Question: What is CRI Pod & Container Metrics?

Answer: C o l l e c t i o n   o f   P o d   &   C o n t a i n e r   m e t r i c s   v i a   t h e   C R I .


Question: What is Node metrics data?

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


Question: What is Understand Pressure Stall Information (PSI) Metrics?

Answer: D e t a i l e d   e x p l a n a t i o n   o f   P r e s s u r e   S t a l l   I n f o r m a t i o n   ( P S I )   m e t r i c s   a n d   h o w   t o   u s e   t h e m   t o   i d e n t i f y   r e s o u r c e   p r e s s u r e   i n   K u b e r n e t e s .


Question: What is Kubernetes z-pages?

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


Question: What is Kubernetes Metrics Reference?

Answer: D e t a i l s   o f   t h e   m e t r i c   d a t a   t h a t   K u b e r n e t e s   c o m p o n e n t s   e x p o r t .


Question: What is Configure Default CPU Requests and Limits for a Namespace?

Answer: Configure Default CPU Requests and Limits for a NamespaceDefine a default CPU resource limits for a namespace, so that every new Pod in that namespace has a CPU resource limit configured.This page shows how to configure default CPU requests and limits for a namespace.A Kubernetes cluster can be divided into namespaces. If you create a Pod within a namespace that has a default CPU limit, and any container in that Pod does not specify its own CPU limit, then the control plane assigns the default CPU limit to that container.Kubernetes assigns a default CPU request, but only under certain conditions that are explained later in this page.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 KubernetesYou must have access to create namespaces in your cluster.If you're not already familiar with what Kubernetes means by 1.0 CPU, read meaning of CPU.Create a namespaceCreate a namespace so that the resources you create in this exercise are isolated from the rest of your cluster.kubectl create namespace default-cpu-example Create a LimitRange and a PodHere's a manifest for an example LimitRange. The manifest specifies a default CPU request and a default CPU limit.admin/resource/cpu-defaults.yaml apiVersion: v1 kind: LimitRange metadata: name: cpu-limit-range spec: limits: - default: cpu: 1 defaultRequest: cpu: 0.5 type: Container Create the LimitRange in the default-cpu-example namespace:kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults.yaml --namespace=default-cpu-example Now if you create a Pod in the default-cpu-example namespace, and any container in that Pod does not specify its own values for CPU request and CPU limit, then the control plane applies default values: a CPU request of 0.5 and a default CPU limit of 1.Here's a manifest for a Pod that has one container. The container does not specify a CPU request and limit.admin/resource/cpu-defaults-pod.yaml apiVersion: v1 kind: Pod metadata: name: default-cpu-demo spec: containers: - name: default-cpu-demo-ctr image: nginx Create the Pod.kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults-pod.yaml --namespace=default-cpu-example View the Pod's specification:kubectl get pod default-cpu-demo --output=yaml --namespace=default-cpu-example The output shows that the Pod's only container has a CPU request of 500m cpu (which you can read as “500 millicpu”), and a CPU limit of 1 cpu. These are the default values specified by the LimitRange.containers: - image: nginx imagePullPolicy: Always name: default-cpu-demo-ctr resources: limits: cpu: "1" requests: cpu: 500m What if you specify a container's limit, but n


Question: How does Configure Default CPU Requests and Limits for a Namespace work?

Answer: Configure Default CPU Requests and Limits for a NamespaceDefine a default CPU resource limits for a namespace, so that every new Pod in that namespace has a CPU resource limit configured.This page shows how to configure default CPU requests and limits for a namespace.A Kubernetes cluster can be divided into namespaces. If you create a Pod within a namespace that has a default CPU limit, and any container in that Pod does not specify its own CPU limit, then the control plane assigns the default CPU limit to that container.Kubernetes assigns a default CPU request, but only under certain conditions that are explained later in this page.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 KubernetesYou must have access to create namespaces in your cluster.If you're not already familiar with what Kubernetes means by 1.0 CPU, read meaning of CPU.Create a namespaceCreate a namespace so that the resources you create in this exercise are isolated from the rest of your cluster.kubectl create namespace default-cpu-example Create a LimitRange and a PodHere's a manifest for an example LimitRange. The manifest specifies a default CPU request and a default CPU limit.admin/resource/cpu-defaults.yaml apiVersion: v1 kind: LimitRange metadata: name: cpu-limit-range spec: limits: - default: cpu: 1 defaultRequest: cpu: 0.5 type: Container Create the LimitRange in the default-cpu-example namespace:kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults.yaml --namespace=default-cpu-example Now if you create a Pod in the default-cpu-example namespace, and any container in that Pod does not specify its own values for CPU request and CPU limit, then the control plane applies default values: a CPU request of 0.5 and a default CPU limit of 1.Here's a manifest for a Pod that has one container. The container does not specify a CPU request and limit.admin/resource/cpu-defaults-pod.yaml apiVersion: v1 kind: Pod metadata: name: default-cpu-demo spec: containers: - name: default-cpu-demo-ctr image: nginx Create the Pod.kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults-pod.yaml --namespace=default-cpu-example View the Pod's specification:kubectl get pod default-cpu-demo --output=yaml --namespace=default-cpu-example The output shows that the Pod's only container has a CPU request of 500m cpu (which you can read as “500 millicpu”), and a CPU limit of 1 cpu. These are the default values specified by the LimitRange.containers: - image: nginx imagePullPolicy: Always name: default-cpu-demo-ctr resources: limits: cpu: "1" requests: cpu: 500m What if you specify a container's limit, but n


Question: When would you use Configure Default CPU Requests and Limits for a Namespace?

Answer: Configure Default CPU Requests and Limits for a NamespaceDefine a default CPU resource limits for a namespace, so that every new Pod in that namespace has a CPU resource limit configured.This page shows how to configure default CPU requests and limits for a namespace.A Kubernetes cluster can be divided into namespaces. If you create a Pod within a namespace that has a default CPU limit, and any container in that Pod does not specify its own CPU limit, then the control plane assigns the default CPU limit to that container.Kubernetes assigns a default CPU request, but only under certain conditions that are explained later in this page.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 KubernetesYou must have access to create namespaces in your cluster.If you're not already familiar with what Kubernetes means by 1.0 CPU, read meaning of CPU.Create a namespaceCreate a namespace so that the resources you create in this exercise are isolated from the rest of your cluster.kubectl create namespace default-cpu-example Create a LimitRange and a PodHere's a manifest for an example LimitRange. The manifest specifies a default CPU request and a default CPU limit.admin/resource/cpu-defaults.yaml apiVersion: v1 kind: LimitRange metadata: name: cpu-limit-range spec: limits: - default: cpu: 1 defaultRequest: cpu: 0.5 type: Container Create the LimitRange in the default-cpu-example namespace:kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults.yaml --namespace=default-cpu-example Now if you create a Pod in the default-cpu-example namespace, and any container in that Pod does not specify its own values for CPU request and CPU limit, then the control plane applies default values: a CPU request of 0.5 and a default CPU limit of 1.Here's a manifest for a Pod that has one container. The container does not specify a CPU request and limit.admin/resource/cpu-defaults-pod.yaml apiVersion: v1 kind: Pod metadata: name: default-cpu-demo spec: containers: - name: default-cpu-demo-ctr image: nginx Create the Pod.kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults-pod.yaml --namespace=default-cpu-example View the Pod's specification:kubectl get pod default-cpu-demo --output=yaml --namespace=default-cpu-example The output shows that the Pod's only container has a CPU request of 500m cpu (which you can read as “500 millicpu”), and a CPU limit of 1 cpu. These are the default values specified by the LimitRange.containers: - image: nginx imagePullPolicy: Always name: default-cpu-demo-ctr resources: limits: cpu: "1" requests: cpu: 500m What if you specify a container's limit, but n


Question: What are the benefits of Configure Default CPU Requests and Limits for a Namespace?

Answer: Configure Default CPU Requests and Limits for a NamespaceDefine a default CPU resource limits for a namespace, so that every new Pod in that namespace has a CPU resource limit configured.This page shows how to configure default CPU requests and limits for a namespace.A Kubernetes cluster can be divided into namespaces. If you create a Pod within a namespace that has a default CPU limit, and any container in that Pod does not specify its own CPU limit, then the control plane assigns the default CPU limit to that container.Kubernetes assigns a default CPU request, but only under certain conditions that are explained later in this page.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 KubernetesYou must have access to create namespaces in your cluster.If you're not already familiar with what Kubernetes means by 1.0 CPU, read meaning of CPU.Create a namespaceCreate a namespace so that the resources you create in this exercise are isolated from the rest of your cluster.kubectl create namespace default-cpu-example Create a LimitRange and a PodHere's a manifest for an example LimitRange. The manifest specifies a default CPU request and a default CPU limit.admin/resource/cpu-defaults.yaml apiVersion: v1 kind: LimitRange metadata: name: cpu-limit-range spec: limits: - default: cpu: 1 defaultRequest: cpu: 0.5 type: Container Create the LimitRange in the default-cpu-example namespace:kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults.yaml --namespace=default-cpu-example Now if you create a Pod in the default-cpu-example namespace, and any container in that Pod does not specify its own values for CPU request and CPU limit, then the control plane applies default values: a CPU request of 0.5 and a default CPU limit of 1.Here's a manifest for a Pod that has one container. The container does not specify a CPU request and limit.admin/resource/cpu-defaults-pod.yaml apiVersion: v1 kind: Pod metadata: name: default-cpu-demo spec: containers: - name: default-cpu-demo-ctr image: nginx Create the Pod.kubectl apply -f https://k8s.io/examples/admin/resource/cpu-defaults-pod.yaml --namespace=default-cpu-example View the Pod's specification:kubectl get pod default-cpu-demo --output=yaml --namespace=default-cpu-example The output shows that the Pod's only container has a CPU request of 500m cpu (which you can read as “500 millicpu”), and a CPU limit of 1 cpu. These are the default values specified by the LimitRange.containers: - image: nginx imagePullPolicy: Always name: default-cpu-demo-ctr resources: limits: cpu: "1" requests: cpu: 500m What if you specify a container's limit, but n


Question: What is Configure Default CPU Requests and Limits for a Namespace?

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   d e f a u l t   C P U   r e q u e s t s   a n d   l i m i t s   f o r   a   n a m e s p a c e .   A   K u b e r n e t e s   c l u s t e r   c a n   b e   d i v i d e d   i n t o   n a m e s p a c e s .   I f   y o u   c r e a t e   a   P o d   w i t h i n   a   n a m e s p a c e   t h a t   h a s   a   d e f a u l t   C P U   l i m i t ,   a n d   a n y   c o n t a i n e r   i n   t h a t   P o d   d o e s   n o t   s p e c i f y   i t s   o w n   C P U   l i m i t ,   t h e n   t h e   c o n t r o l   p l a n e   a s s i g n s   t h e   d e f a u l t   C P U   l i m i t   t o   t h a t   c o n t a i n e r .   K u b e r n e t e s   a s s i g n s   a   d e f a u l t   C P U   r e q u e s t ,   b u t   o n l y   u n d e r   c e r t a i n   c o n d i t i o n s   t h a t   a r e   e x p l a i n e d   l a t e r   i n   t h i s   p a g 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 ,   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   Y o u   m u s t   h a v e   a c c e s s   t o   c r e a t e   n a m e s p a c e s   i n   y o u r   c l u s t e r .   I f   y o u ' r e   n o t   a l r e a d y   f a m i l i a r   w i t h   w h a t   K u b e r n e t e s   m e a n s   b y   1 . 0   C P U ,   r e a d   m e a n i n g   o f   C P U .


Question: What is Create a namespace?

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


Question: What is Create a LimitRange and a Pod?

Answer: H e r e ' s   a   m a n i f e s t   f o r   a n   e x a m p l e   L i m i t R a n g e .   T h e   m a n i f e s t   s p e c i f i e s   a   d e f a u l t   C P U   r e q u e s t   a n d   a   d e f a u l t   C P U   l i m i t .   a p i V e r s i o n :   v 1   k i n d :   L i m i t R a n g e   m e t a d a t a :   n a m e :   c p u - l i m i t - r a n g e   s p e c :   l i m i t s :   -   d e f a u l t :   c p u :   1   d e f a u l t R e q u e s t :   c p u :   0 . 5   t y p e :   C o n t a i n e r   C r e a t e   t h e   L i m i t R a n g e   i n   t h e   d e f a u l t - c p u - e x a m p l e   n a m e s p a c e :   k u b e c t l   a p p l y   - f   h t t p s : / / k 8 s . i o / e x a m p l e s / a d m i n / r e s o u r c e / c p u - d e f a u l t s . y a m l   - - n a m e s p a c e = d e f a u l t - c p u - e x a m p l e   N o w   i f   y o u   c r e a t e   a   P o d   i n   t h e   d e f a u l t - c p u - e x a m p l e   n a m e s p a c e ,   a n d   a n y   c o n t a i n e r   i n   t h a t   P o d   d o e s   n o t   s p e c i f y   i t s   o w n   v a l u e s   f o r   C P U   r e q u e s t   a n d   C P U   l i m i t ,   t h e n   t h e   c o n t r o l   p l a n e   a p p l i e s   d e f a u l t   v a l u e s :   a   C P U   r e q u e s t   o f   0 . 5   a n d   a   d e f a u l t   C P U   l i m i t   o f   1 .   H e r e ' s   a   m a n i f e s t   f o r   a   P o d   t h a t   h a s   o n e   c o n t a i n e r .   T h e   c o n t a i n e r   d o e s   n o t   s p e c i f y   a   C P U   r e q u e s t   a n d   l i m i t .   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 :   n a m e :   d e f a u l t - c p u - d e m o   s p e c :   c o n t a i n e r s :   -   n a m e :   d e f a u l t - c p u - d e m o - c t r   i m a g e :   n g i n x   C r e a t e   t h e   P o d .   k u b e c t l   a p p l y   - f   h t t p s : / / k 8 s . i o / e x a m p l e s / a d m i n / r e s o u r c e / c p u - d e f a u l t s - p o d . y a m l   - - n a m e s p a


Question: What is What if you specify a container's limit, but not its request??

Answer: H e r e ' s   a   m a n i f e s t   f o r   a   P o d   t h a t   h a s   o n e   c o n t a i n e r .   T h e   c o n t a i n e r   s p e c i f i e s   a   C P U   l i m i t ,   b u t   n o t   a   r e q u e s t :   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 :   n a m e :   d e f a u l t - c p u - d e m o - 2   s p e c :   c o n t a i n e r s :   -   n a m e :   d e f a u l t - c p u - d e m o - 2 - c t r   i m a g e :   n g i n x   r e s o u r c e s :   l i m i t s :   c p u :   " 1 "   C r e a t e   t h e   P o d :   k u b e c t l   a p p l y   - f   h t t p s : / / k 8 s . i o / e x a m p l e s / a d m i n / r e s o u r c e / c p u - d e f a u l t s - p o d - 2 . y a m l   - - n a m e s p a c e = d e f a u l t - c p u - e x a m p l e   V i e w   t h e   s p e c i f i c a t i o n   o f   t h e   P o d   t h a t   y o u   c r e a t e d :   k u b e c t l   g e t   p o d   d e f a u l t - c p u - d e m o - 2   - - o u t p u t = y a m l   - - n a m e s p a c e = d e f a u l t - c p u - e x a m p l e   T h e   o u t p u t   s h o w s   t h a t   t h e   c o n t a i n e r ' s   C P U   r e q u e s t   i s   s e t   t o   m a t c h   i t s   C P U   l i m i t .   N o t i c e   t h a t   t h e   c o n t a i n e r   w a s   n o t   a s s i g n e d   t h e   d e f a u l t   C P U   r e q u e s t   v a l u e   o f   0 . 5   c p u :   r e s o u r c e s :   l i m i t s :   c p u :   " 1 "   r e q u e s t s :   c p u :   " 1 "


Question: What is What if you specify a container's request, but not its limit??

Answer: H e r e ' s   a n   e x a m p l e   m a n i f e s t   f o r   a   P o d   t h a t   h a s   o n e   c o n t a i n e r .   T h e   c o n t a i n e r   s p e c i f i e s   a   C P U   r e q u e s t ,   b u t   n o t   a   l i m i t :   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 :   n a m e :   d e f a u l t - c p u - d e m o - 3   s p e c :   c o n t a i n e r s :   -   n a m e :   d e f a u l t - c p u - d e m o - 3 - c t r   i m a g e :   n g i n x   r e s o u r c e s :   r e q u e s t s :   c p u :   " 0 . 7 5 "   C r e a t e   t h e   P o d :   k u b e c t l   a p p l y   - f   h t t p s : / / k 8 s . i o / e x a m p l e s / a d m i n / r e s o u r c e / c p u - d e f a u l t s - p o d - 3 . y a m l   - - n a m e s p a c e = d e f a u l t - c p u - e x a m p l e   V i e w   t h e   s p e c i f i c a t i o n   o f   t h e   P o d   t h a t   y o u   c r e a t e d :   k u b e c t l   g e t   p o d   d e f a u l t - c p u - d e m o - 3   - - o u t p u t = y a m l   - - n a m e s p a c e = d e f a u l t - c p u - e x a m p l e   T h e   o u t p u t   s h o w s   t h a t   t h e   c o n t a i n e r ' s   C P U   r e q u e s t   i s   s e t   t o   t h e   v a l u e   y o u   s p e c i f i e d   a t   t h e   t i m e   y o u   c r e a t e d   t h e   P o d   ( i n   o t h e r   w o r d s :   i t   m a t c h e s   t h e   m a n i f e s t ) .   H o w e v e r ,   t h e   s a m e   c o n t a i n e r ' s   C P U   l i m i t   i s   s e t   t o   1   c p u ,   w h i c h   i s   t h e   d e f a u l t   C P U   l i m i t   f o r   t h a t   n a m e s p a c e .   r e s o u r c e s :   l i m i t s :   c p u :   " 1 "   r e q u e s t s :   c p u :   7 5 0 m


Question: What is Motivation for default CPU limits and requests?

Answer: I f   y o u r   n a m e s p a c e   h a s   a   C P U   r e s o u r c e   q u o t a   c o n f i g u r e d ,   i t   i s   h e l p f u l   t o   h a v e   a   d e f a u l t   v a l u e   i n   p l a c e   f o r   C P U   l i m i t .   H e r e   a r e   t w o   o f   t h e   r e s t r i c t i o n s   t h a t   a   C P U   r e s o u r c e   q u o t a   i m p o s e s   o n   a   n a m e s p a c e :   F o r   e v e r y   P o d   t h a t   r u n s   i n   t h e   n a m e s p a c e ,   e a c h   o f   i t s   c o n t a i n e r s   m u s t   h a v e   a   C P U   l i m i t . C P U   l i m i t s   a p p l y   a   r e s o u r c e   r e s e r v a t i o n   o n   t h e   n o d e   w h e r e   t h e   P o d   i n   q u e s t i o n   i s   s c h e d u l e d .   T h e   t o t a l   a m o u n t   o f   C P U   t h a t   i s   r e s e r v e d   f o r   u s e   b y   a l l   P o d s   i n   t h e   n a m e s p a c e   m u s t   n o t   e x c e e d   a   s p e c i f i e d   l i m i t .   W h e n   y o u   a d d   a   L i m i t R a n g e :   I f   a n y   P o d   i n   t h a t   n a m e s p a c e   t h a t   i n c l u d e s   a   c o n t a i n e r   d o e s   n o t   s p e c i f y   i t s   o w n   C P U   l i m i t ,   t h e   c o n t r o l   p l a n e   a p p l i e s   t h e   d e f a u l t   C P U   l i m i t   t o   t h a t   c o n t a i n e r ,   a n d   t h e   P o d   c a n   b e   a l l o w e d   t o   r u n   i n   a   n a m e s p a c e   t h a t   i s   r e s t r i c t e d   b y   a   C P U   R e s o u r c e Q u o t a .


Question: What is Clean up?

Answer: D e l e t e   y o u r   n a m e s p a c e :   k u b e c t l   d e l e t e   n a m e s p a c e   d e f a u l t - c p u - e x a m p l e


Question: What is For cluster administrators?

Answer: C o n f i g u r e   D e f a u l t   M e m o r y   R e q u e s t s   a n d   L i m i t s   f o r   a   N a m e s p a c e C o n f i g u r e   M i n i m u m   a n d   M a x i m u m   M e m o r y   C o n s t r a i n t s   f o r   a   N a m e s p a c e C o n f i g u r e   M i n i m u m   a n d   M a x i m u m   C P U   C o n s t r a i n t s   f o r   a   N a m e s p a c e C o n f i g u r e   M e m o r y   a n d   C P U   Q u o t a s   f o r   a   N a m e s p a c e C o n f i g u r e   a   P o d   Q u o t a   f o r   a   N a m e s p a c e C o n f i g u r e   Q u o t a s   f o r   A P I   O b j e c t s   C o n f i g u r e   D e f a u l t   M e m o r y   R e q u e s t s   a n d   L i m i t s   f o r   a   N a m e s p a c e   C o n f i g u r e   M i n i m u m   a n d   M a x i m u m   M e m o r y   C o n s t r a i n t s   f o r   a   N a m e s p a c e   C o n f i g u r e   M i n i m u m   a n d   M a x i m u m   C P U   C o n s t r a i n t s   f o r   a   N a m e s p a c e   C o n f i g u r e   M e m o r y   a n d   C P U   Q u o t a s   f o r   a   N a m e s p a c e   C o n f i g u r e   a   P o d   Q u o t a   f o r   a   N a m e s p a c e   C o n f i g u r e   Q u o t a s   f o r   A P I   O b j e c t s


Question: What is For app developers?

Answer: A s s i g n   M e m o r y   R e s o u r c e s   t o   C o n t a i n e r s   a n d   P o d s A s s i g n   C P U   R e s o u r c e s   t o   C o n t a i n e r s   a n d   P o d s A s s i g n   P o d - l e v e l   C P U   a n d   m e m o r y   r e s o u r c e s C o n f i g u r e   Q u a l i t y   o f   S e r v i c e   f o r   P o d s   A s s i g n   M e m o r y   R e s o u r c e s   t o   C o n t a i n e r s   a n d   P o d s   A s s i g n   C P U   R e s o u r c e s   t o   C o n t a i n e r s   a n d   P o d s   A s s i g n   P o d - l e v e l   C P U   a n d   m e m o r y   r e s o u r c e s   C o n f i g u r e   Q u a l i t y   o f   S e r v i c e   f o r   P o d s


Question: What is Scheduler Performance Tuning?

Answer: Scheduler Performance TuningFEATURE STATE: Kubernetes v1.14 [beta]kube-scheduler is the Kubernetes default scheduler. It is responsible for placement of Pods on Nodes in a cluster.Nodes in a cluster that meet the scheduling requirements of a Pod are called feasible Nodes for the Pod. The scheduler finds feasible Nodes for a Pod and then runs a set of functions to score the feasible Nodes, picking a Node with the highest score among the feasible ones to run the Pod. The scheduler then notifies the API server about this decision in a process called Binding.This page explains performance tuning optimizations that are relevant for large Kubernetes clusters.In large clusters, you can tune the scheduler's behaviour balancing scheduling outcomes between latency (new Pods are placed quickly) and accuracy (the scheduler rarely makes poor placement decisions).You configure this tuning setting via kube-scheduler setting percentageOfNodesToScore. This KubeSchedulerConfiguration setting determines a threshold for scheduling nodes in your cluster.Setting the thresholdThe percentageOfNodesToScore option accepts whole numeric values between 0 and 100. The value 0 is a special number which indicates that the kube-scheduler should use its compiled-in default. If you set percentageOfNodesToScore above 100, kube-scheduler acts as if you had set a value of 100.To change the value, edit the kube-scheduler configuration file and then restart the scheduler. In many cases, the configuration file can be found at /etc/kubernetes/config/kube-scheduler.yaml.After you have made this change, you can runkubectl get pods -n kube-system | grep kube-scheduler to verify that the kube-scheduler component is healthy.Node scoring thresholdTo improve scheduling performance, the kube-scheduler can stop looking for feasible nodes once it has found enough of them. In large clusters, this saves time compared to a naive approach that would consider every node.You specify a threshold for how many nodes are enough, as a whole number percentage of all the nodes in your cluster. The kube-scheduler converts this into an integer number of nodes. During scheduling, if the kube-scheduler has identified enough feasible nodes to exceed the configured percentage, the kube-scheduler stops searching for more feasible nodes and moves on to the scoring phase.How the scheduler iterates over Nodes describes the process in detail.Default thresholdIf you don't specify a threshold, Kubernetes calculates a figure using a linear formula that yields 50% for a 100-node cluster and yields 10% for a 5000-node cluster. The lower bound for the automatic value is 5%.This means that the kube-scheduler always scores at least 5% of your cluster no matter how large the cluster is, unless you have explicitly set percentageOfNodesToScore to be smaller than 5.If you want the scheduler to score all nodes in your cluster, set percentageOfNodesToScore to 100.ExampleBelow is an example configuration that sets percentageOfNodesToS


Question: How does Scheduler Performance Tuning work?

Answer: Scheduler Performance TuningFEATURE STATE: Kubernetes v1.14 [beta]kube-scheduler is the Kubernetes default scheduler. It is responsible for placement of Pods on Nodes in a cluster.Nodes in a cluster that meet the scheduling requirements of a Pod are called feasible Nodes for the Pod. The scheduler finds feasible Nodes for a Pod and then runs a set of functions to score the feasible Nodes, picking a Node with the highest score among the feasible ones to run the Pod. The scheduler then notifies the API server about this decision in a process called Binding.This page explains performance tuning optimizations that are relevant for large Kubernetes clusters.In large clusters, you can tune the scheduler's behaviour balancing scheduling outcomes between latency (new Pods are placed quickly) and accuracy (the scheduler rarely makes poor placement decisions).You configure this tuning setting via kube-scheduler setting percentageOfNodesToScore. This KubeSchedulerConfiguration setting determines a threshold for scheduling nodes in your cluster.Setting the thresholdThe percentageOfNodesToScore option accepts whole numeric values between 0 and 100. The value 0 is a special number which indicates that the kube-scheduler should use its compiled-in default. If you set percentageOfNodesToScore above 100, kube-scheduler acts as if you had set a value of 100.To change the value, edit the kube-scheduler configuration file and then restart the scheduler. In many cases, the configuration file can be found at /etc/kubernetes/config/kube-scheduler.yaml.After you have made this change, you can runkubectl get pods -n kube-system | grep kube-scheduler to verify that the kube-scheduler component is healthy.Node scoring thresholdTo improve scheduling performance, the kube-scheduler can stop looking for feasible nodes once it has found enough of them. In large clusters, this saves time compared to a naive approach that would consider every node.You specify a threshold for how many nodes are enough, as a whole number percentage of all the nodes in your cluster. The kube-scheduler converts this into an integer number of nodes. During scheduling, if the kube-scheduler has identified enough feasible nodes to exceed the configured percentage, the kube-scheduler stops searching for more feasible nodes and moves on to the scoring phase.How the scheduler iterates over Nodes describes the process in detail.Default thresholdIf you don't specify a threshold, Kubernetes calculates a figure using a linear formula that yields 50% for a 100-node cluster and yields 10% for a 5000-node cluster. The lower bound for the automatic value is 5%.This means that the kube-scheduler always scores at least 5% of your cluster no matter how large the cluster is, unless you have explicitly set percentageOfNodesToScore to be smaller than 5.If you want the scheduler to score all nodes in your cluster, set percentageOfNodesToScore to 100.ExampleBelow is an example configuration that sets percentageOfNodesToS


Question: When would you use Scheduler Performance Tuning?

Answer: Scheduler Performance TuningFEATURE STATE: Kubernetes v1.14 [beta]kube-scheduler is the Kubernetes default scheduler. It is responsible for placement of Pods on Nodes in a cluster.Nodes in a cluster that meet the scheduling requirements of a Pod are called feasible Nodes for the Pod. The scheduler finds feasible Nodes for a Pod and then runs a set of functions to score the feasible Nodes, picking a Node with the highest score among the feasible ones to run the Pod. The scheduler then notifies the API server about this decision in a process called Binding.This page explains performance tuning optimizations that are relevant for large Kubernetes clusters.In large clusters, you can tune the scheduler's behaviour balancing scheduling outcomes between latency (new Pods are placed quickly) and accuracy (the scheduler rarely makes poor placement decisions).You configure this tuning setting via kube-scheduler setting percentageOfNodesToScore. This KubeSchedulerConfiguration setting determines a threshold for scheduling nodes in your cluster.Setting the thresholdThe percentageOfNodesToScore option accepts whole numeric values between 0 and 100. The value 0 is a special number which indicates that the kube-scheduler should use its compiled-in default. If you set percentageOfNodesToScore above 100, kube-scheduler acts as if you had set a value of 100.To change the value, edit the kube-scheduler configuration file and then restart the scheduler. In many cases, the configuration file can be found at /etc/kubernetes/config/kube-scheduler.yaml.After you have made this change, you can runkubectl get pods -n kube-system | grep kube-scheduler to verify that the kube-scheduler component is healthy.Node scoring thresholdTo improve scheduling performance, the kube-scheduler can stop looking for feasible nodes once it has found enough of them. In large clusters, this saves time compared to a naive approach that would consider every node.You specify a threshold for how many nodes are enough, as a whole number percentage of all the nodes in your cluster. The kube-scheduler converts this into an integer number of nodes. During scheduling, if the kube-scheduler has identified enough feasible nodes to exceed the configured percentage, the kube-scheduler stops searching for more feasible nodes and moves on to the scoring phase.How the scheduler iterates over Nodes describes the process in detail.Default thresholdIf you don't specify a threshold, Kubernetes calculates a figure using a linear formula that yields 50% for a 100-node cluster and yields 10% for a 5000-node cluster. The lower bound for the automatic value is 5%.This means that the kube-scheduler always scores at least 5% of your cluster no matter how large the cluster is, unless you have explicitly set percentageOfNodesToScore to be smaller than 5.If you want the scheduler to score all nodes in your cluster, set percentageOfNodesToScore to 100.ExampleBelow is an example configuration that sets percentageOfNodesToS


Question: What are the benefits of Scheduler Performance Tuning?

Answer: Scheduler Performance TuningFEATURE STATE: Kubernetes v1.14 [beta]kube-scheduler is the Kubernetes default scheduler. It is responsible for placement of Pods on Nodes in a cluster.Nodes in a cluster that meet the scheduling requirements of a Pod are called feasible Nodes for the Pod. The scheduler finds feasible Nodes for a Pod and then runs a set of functions to score the feasible Nodes, picking a Node with the highest score among the feasible ones to run the Pod. The scheduler then notifies the API server about this decision in a process called Binding.This page explains performance tuning optimizations that are relevant for large Kubernetes clusters.In large clusters, you can tune the scheduler's behaviour balancing scheduling outcomes between latency (new Pods are placed quickly) and accuracy (the scheduler rarely makes poor placement decisions).You configure this tuning setting via kube-scheduler setting percentageOfNodesToScore. This KubeSchedulerConfiguration setting determines a threshold for scheduling nodes in your cluster.Setting the thresholdThe percentageOfNodesToScore option accepts whole numeric values between 0 and 100. The value 0 is a special number which indicates that the kube-scheduler should use its compiled-in default. If you set percentageOfNodesToScore above 100, kube-scheduler acts as if you had set a value of 100.To change the value, edit the kube-scheduler configuration file and then restart the scheduler. In many cases, the configuration file can be found at /etc/kubernetes/config/kube-scheduler.yaml.After you have made this change, you can runkubectl get pods -n kube-system | grep kube-scheduler to verify that the kube-scheduler component is healthy.Node scoring thresholdTo improve scheduling performance, the kube-scheduler can stop looking for feasible nodes once it has found enough of them. In large clusters, this saves time compared to a naive approach that would consider every node.You specify a threshold for how many nodes are enough, as a whole number percentage of all the nodes in your cluster. The kube-scheduler converts this into an integer number of nodes. During scheduling, if the kube-scheduler has identified enough feasible nodes to exceed the configured percentage, the kube-scheduler stops searching for more feasible nodes and moves on to the scoring phase.How the scheduler iterates over Nodes describes the process in detail.Default thresholdIf you don't specify a threshold, Kubernetes calculates a figure using a linear formula that yields 50% for a 100-node cluster and yields 10% for a 5000-node cluster. The lower bound for the automatic value is 5%.This means that the kube-scheduler always scores at least 5% of your cluster no matter how large the cluster is, unless you have explicitly set percentageOfNodesToScore to be smaller than 5.If you want the scheduler to score all nodes in your cluster, set percentageOfNodesToScore to 100.ExampleBelow is an example configuration that sets percentageOfNodesToS


Question: What is Scheduler Performance Tuning?

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


Question: What is Setting the threshold?

Answer: T h e   p e r c e n t a g e O f N o d e s T o S c o r e   o p t i o n   a c c e p t s   w h o l e   n u m e r i c   v a l u e s   b e t w e e n   0   a n d   1 0 0 .   T h e   v a l u e   0   i s   a   s p e c i a l   n u m b e r   w h i c h   i n d i c a t e s   t h a t   t h e   k u b e - s c h e d u l e r   s h o u l d   u s e   i t s   c o m p i l e d - i n   d e f a u l t .   I f   y o u   s e t   p e r c e n t a g e O f N o d e s T o S c o r e   a b o v e   1 0 0 ,   k u b e - s c h e d u l e r   a c t s   a s   i f   y o u   h a d   s e t   a   v a l u e   o f   1 0 0 .   T o   c h a n g e   t h e   v a l u e ,   e d i t   t h e   k u b e - s c h e d u l e r   c o n f i g u r a t i o n   f i l e   a n d   t h e n   r e s t a r t   t h e   s c h e d u l e r .   I n   m a n y   c a s e s ,   t h e   c o n f i g u r a t i o n   f i l e   c a n   b e   f o u n d   a t   / e t c / k u b e r n e t e s / c o n f i g / k u b e - s c h e d u l e r . y a m l .   A f t e r   y o u   h a v e   m a d e   t h i s   c h a n g e ,   y o u   c a n   r u n   k u b e c t l   g e t   p o d s   - n   k u b e - s y s t e m   |   g r e p   k u b e - s c h e d u l e r   t o   v e r i f y   t h a t   t h e   k u b e - s c h e d u l e r   c o m p o n e n t   i s   h e a l t h y .


Question: What is Node scoring threshold?

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


Question: What is Default threshold?

Answer: I f   y o u   d o n ' t   s p e c i f y   a   t h r e s h o l d ,   K u b e r n e t e s   c a l c u l a t e s   a   f i g u r e   u s i n g   a   l i n e a r   f o r m u l a   t h a t   y i e l d s   5 0 %   f o r   a   1 0 0 - n o d e   c l u s t e r   a n d   y i e l d s   1 0 %   f o r   a   5 0 0 0 - n o d e   c l u s t e r .   T h e   l o w e r   b o u n d   f o r   t h e   a u t o m a t i c   v a l u e   i s   5 % .   T h i s   m e a n s   t h a t   t h e   k u b e - s c h e d u l e r   a l w a y s   s c o r e s   a t   l e a s t   5 %   o f   y o u r   c l u s t e r   n o   m a t t e r   h o w   l a r g e   t h e   c l u s t e r   i s ,   u n l e s s   y o u   h a v e   e x p l i c i t l y   s e t   p e r c e n t a g e O f N o d e s T o S c o r e   t o   b e   s m a l l e r   t h a n   5 .   I f   y o u   w a n t   t h e   s c h e d u l e r   t o   s c o r e   a l l   n o d e s   i n   y o u r   c l u s t e r ,   s e t   p e r c e n t a g e O f N o d e s T o S c o r e   t o   1 0 0 .


Question: What is Example?

Answer: B e l o w   i s   a n   e x a m p l e   c o n f i g u r a t i o n   t h a t   s e t s   p e r c e n t a g e O f N o d e s T o S c o r e   t o   5 0 % .   a p i V e r s i o n :   k u b e s c h e d u l e r . c o n f i g . k 8 s . i o / v 1 a l p h a 1   k i n d :   K u b e S c h e d u l e r C o n f i g u r a t i o n   a l g o r i t h m S o u r c e :   p r o v i d e r :   D e f a u l t P r o v i d e r   . . .   p e r c e n t a g e O f N o d e s T o S c o r e :   5 0


Question: What is Tuning percentageOfNodesToScore?

Answer: p e r c e n t a g e O f N o d e s T o S c o r e   m u s t   b e   a   v a l u e   b e t w e e n   1   a n d   1 0 0   w i t h   t h e   d e f a u l t   v a l u e   b e i n g   c a l c u l a t e d   b a s e d   o n   t h e   c l u s t e r   s i z e .   T h e r e   i s   a l s o   a   h a r d c o d e d   m i n i m u m   v a l u e   o f   1 0 0   n o d e s .


Question: What is Note:?

Answer: I n   c l u s t e r s   w i t h   l e s s   t h a n   1 0 0   f e a s i b l e   n o d e s ,   t h e   s c h e d u l e r   s t i l l   c h e c k s   a l l   t h e   n o d e s   b e c a u s e   t h e r e   a r e   n o t   e n o u g h   f e a s i b l e   n o d e s   t o   s t o p   t h e   s c h e d u l e r ' s   s e a r c h   e a r l y .   I n   a   s m a l l   c l u s t e r ,   i f   y o u   s e t   a   l o w   v a l u e   f o r   p e r c e n t a g e O f N o d e s T o S c o r e ,   y o u r   c h a n g e   w i l l   h a v e   n o   o r   l i t t l e   e f f e c t ,   f o r   a   s i m i l a r   r e a s o n .   I f   y o u r   c l u s t e r   h a s   s e v e r a l   h u n d r e d   N o d e s   o r   f e w e r ,   l e a v e   t h i s   c o n f i g u r a t i o n   o p t i o n   a t   i t s   d e f a u l t   v a l u e .   M a k i n g   c h a n g e s   i s   u n l i k e l y   t o   i m p r o v e   t h e   s c h e d u l e r ' s   p e r f o r m a n c e   s i g n i f i c a n t l y .   A n   i m p o r t a n t   d e t a i l   t o   c o n s i d e r   w h e n   s e t t i n g   t h i s   v a l u e   i s   t h a t   w h e n   a   s m a l l e r   n u m b e r   o f   n o d e s   i n   a   c l u s t e r   a r e   c h e c k e d   f o r   f e a s i b i l i t y ,   s o m e   n o d e s   a r e   n o t   s e n t   t o   b e   s c o r e d   f o r   a   g i v e n   P o d .   A s   a   r e s u l t ,   a   N o d e   w h i c h   c o u l d   p o s s i b l y   s c o r e   a   h i g h e r   v a l u e   f o r   r u n n i n g   t h e   g i v e n   P o d   m i g h t   n o t   e v e n   b e   p a s s e d   t o   t h e   s c o r i n g   p h a s e .   T h i s   w o u l d   r e s u l t   i n   a   l e s s   t h a n   i d e a l   p l a c e m e n t   o f   t h e   P o d .   Y o u   s h o u l d   a v o i d   s e t t i n g   p e r c e n t a g e O f N o d e s T o S c o r e   v e r y   l o w   s o   t h a t   k u b e - s c h e d u l e r   d o e s   n o t   m a k e   f r e q u e n t ,   p o o r   P o d   p l a


Question: What is How the scheduler iterates over Nodes?

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


Question: What is What's next?

Answer: C h e c k   t h e   k u b e - s c h e d u l e r   c o n f i g u r a t i o n   r e f e r e n c e   ( v 1 )


Question: What is Building a Basic DaemonSet?

Answer: Building a Basic DaemonSetThis page demonstrates how to build a basic DaemonSet that runs a Pod on every node in a Kubernetes cluster. It covers a simple use case of mounting a file from the host, logging its contents using an init container, and utilizing a pause container.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 KubernetesA Kubernetes cluster with at least two nodes (one control plane node and one worker node) to demonstrate the behavior of DaemonSets.Define the DaemonSetIn this task, a basic DaemonSet is created which ensures that the copy of a Pod is scheduled on every node. The Pod will use an init container to read and log the contents of /etc/machine-id from the host, while the main container will be a pause container, which keeps the Pod running.application/basic-daemonset.yaml apiVersion: apps/v1 kind: DaemonSet metadata: name: example-daemonset spec: selector: matchLabels: app.kubernetes.io/name: example template: metadata: labels: app.kubernetes.io/name: example spec: containers: - name: pause image: registry.k8s.io/pause initContainers: - name: log-machine-id image: busybox:1.37 command: ['sh', '-c', 'cat /etc/machine-id > /var/log/machine-id.log'] volumeMounts: - name: machine-id mountPath: /etc/machine-id readOnly: true - name: log-dir mountPath: /var/log volumes: - name: machine-id hostPath: path: /etc/machine-id type: File - name: log-dir hostPath: path: /var/logCreate a DaemonSet based on the (YAML) manifest:kubectl apply -f https://k8s.io/examples/application/basic-daemonset.yaml Once applied, you can verify that the DaemonSet is running a Pod on every node in the cluster:kubectl get pods -o wide The output will list one Pod per node, similar to:NAME READY STATUS RESTARTS AGE IP NODE example-daemonset-xxxxx 1/1 Running 0 5m x.x.x.x node-1 example-daemonset-yyyyy 1/1 Running 0 5m x.x.x.x node-2 You can inspect the contents of the logged /etc/machine-id file by checking the log directory mounted from the host:kubectl exec <pod-name> -- cat /var/log/machine-id.log Where <pod-name> is the name of one of your Pods.Cleaning upTo delete the DaemonSet, run this command:kubectl delete --cascade=foreground --ignore-not-found --now daemonsets/example-daemonset This simple DaemonSet example introduces key components like init containers and host path volumes, which can be expanded upon for more advanced use cases. For more details refer to DaemonSet.What's nextSee Performing a rolling update on a DaemonSetSee Creating a DaemonSet to adopt existing DaemonSet pods


Question: How does Building a Basic DaemonSet work?

Answer: Building a Basic DaemonSetThis page demonstrates how to build a basic DaemonSet that runs a Pod on every node in a Kubernetes cluster. It covers a simple use case of mounting a file from the host, logging its contents using an init container, and utilizing a pause container.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 KubernetesA Kubernetes cluster with at least two nodes (one control plane node and one worker node) to demonstrate the behavior of DaemonSets.Define the DaemonSetIn this task, a basic DaemonSet is created which ensures that the copy of a Pod is scheduled on every node. The Pod will use an init container to read and log the contents of /etc/machine-id from the host, while the main container will be a pause container, which keeps the Pod running.application/basic-daemonset.yaml apiVersion: apps/v1 kind: DaemonSet metadata: name: example-daemonset spec: selector: matchLabels: app.kubernetes.io/name: example template: metadata: labels: app.kubernetes.io/name: example spec: containers: - name: pause image: registry.k8s.io/pause initContainers: - name: log-machine-id image: busybox:1.37 command: ['sh', '-c', 'cat /etc/machine-id > /var/log/machine-id.log'] volumeMounts: - name: machine-id mountPath: /etc/machine-id readOnly: true - name: log-dir mountPath: /var/log volumes: - name: machine-id hostPath: path: /etc/machine-id type: File - name: log-dir hostPath: path: /var/logCreate a DaemonSet based on the (YAML) manifest:kubectl apply -f https://k8s.io/examples/application/basic-daemonset.yaml Once applied, you can verify that the DaemonSet is running a Pod on every node in the cluster:kubectl get pods -o wide The output will list one Pod per node, similar to:NAME READY STATUS RESTARTS AGE IP NODE example-daemonset-xxxxx 1/1 Running 0 5m x.x.x.x node-1 example-daemonset-yyyyy 1/1 Running 0 5m x.x.x.x node-2 You can inspect the contents of the logged /etc/machine-id file by checking the log directory mounted from the host:kubectl exec <pod-name> -- cat /var/log/machine-id.log Where <pod-name> is the name of one of your Pods.Cleaning upTo delete the DaemonSet, run this command:kubectl delete --cascade=foreground --ignore-not-found --now daemonsets/example-daemonset This simple DaemonSet example introduces key components like init containers and host path volumes, which can be expanded upon for more advanced use cases. For more details refer to DaemonSet.What's nextSee Performing a rolling update on a DaemonSetSee Creating a DaemonSet to adopt existing DaemonSet pods


Question: When would you use Building a Basic DaemonSet?

Answer: Building a Basic DaemonSetThis page demonstrates how to build a basic DaemonSet that runs a Pod on every node in a Kubernetes cluster. It covers a simple use case of mounting a file from the host, logging its contents using an init container, and utilizing a pause container.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 KubernetesA Kubernetes cluster with at least two nodes (one control plane node and one worker node) to demonstrate the behavior of DaemonSets.Define the DaemonSetIn this task, a basic DaemonSet is created which ensures that the copy of a Pod is scheduled on every node. The Pod will use an init container to read and log the contents of /etc/machine-id from the host, while the main container will be a pause container, which keeps the Pod running.application/basic-daemonset.yaml apiVersion: apps/v1 kind: DaemonSet metadata: name: example-daemonset spec: selector: matchLabels: app.kubernetes.io/name: example template: metadata: labels: app.kubernetes.io/name: example spec: containers: - name: pause image: registry.k8s.io/pause initContainers: - name: log-machine-id image: busybox:1.37 command: ['sh', '-c', 'cat /etc/machine-id > /var/log/machine-id.log'] volumeMounts: - name: machine-id mountPath: /etc/machine-id readOnly: true - name: log-dir mountPath: /var/log volumes: - name: machine-id hostPath: path: /etc/machine-id type: File - name: log-dir hostPath: path: /var/logCreate a DaemonSet based on the (YAML) manifest:kubectl apply -f https://k8s.io/examples/application/basic-daemonset.yaml Once applied, you can verify that the DaemonSet is running a Pod on every node in the cluster:kubectl get pods -o wide The output will list one Pod per node, similar to:NAME READY STATUS RESTARTS AGE IP NODE example-daemonset-xxxxx 1/1 Running 0 5m x.x.x.x node-1 example-daemonset-yyyyy 1/1 Running 0 5m x.x.x.x node-2 You can inspect the contents of the logged /etc/machine-id file by checking the log directory mounted from the host:kubectl exec <pod-name> -- cat /var/log/machine-id.log Where <pod-name> is the name of one of your Pods.Cleaning upTo delete the DaemonSet, run this command:kubectl delete --cascade=foreground --ignore-not-found --now daemonsets/example-daemonset This simple DaemonSet example introduces key components like init containers and host path volumes, which can be expanded upon for more advanced use cases. For more details refer to DaemonSet.What's nextSee Performing a rolling update on a DaemonSetSee Creating a DaemonSet to adopt existing DaemonSet pods