Question: How does Administer a Cluster work?

Answer: Administer a ClusterLearn common tasks for administering a cluster.Administration with kubeadmOverprovision Node Capacity For A ClusterMigrating from dockershimGenerate Certificates ManuallyManage Memory, CPU, and API ResourcesInstall a Network Policy ProviderAccess Clusters Using the Kubernetes APIAdvertise Extended Resources for a NodeAutoscale the DNS Service in a ClusterChange the Access Mode of a PersistentVolume to ReadWriteOncePodChange the default StorageClassSwitching from Polling to CRI Event-based Updates to Container StatusChange the Reclaim Policy of a PersistentVolumeCloud Controller Manager AdministrationConfigure a kubelet image credential providerConfigure Quotas for API ObjectsControl CPU Management Policies on the NodeControl Topology Management Policies on a nodeCustomizing DNS ServiceDebugging DNS ResolutionDeclare Network PolicyDeveloping Cloud Controller ManagerEnable Or Disable A Kubernetes APIEncrypting Confidential Data at RestDecrypt Confidential Data that is Already Encrypted at RestGuaranteed Scheduling For Critical Add-On PodsIP Masquerade Agent User GuideLimit Storage ConsumptionMigrate Replicated Control Plane To Use Cloud Controller ManagerOperating etcd clusters for KubernetesReserve Compute Resources for System DaemonsRunning Kubernetes Node Components as a Non-root UserSafely Drain a NodeSecuring a ClusterSet Kubelet Parameters Via A Configuration FileShare a Cluster with NamespacesUpgrade A ClusterUse Cascading Deletion in a ClusterUsing a KMS provider for data encryptionUsing CoreDNS for Service DiscoveryUsing NodeLocal DNSCache in Kubernetes ClustersUsing sysctls in a Kubernetes ClusterUtilizing the NUMA-aware Memory ManagerVerify Signed Kubernetes Artifacts


Question: When would you use Administer a Cluster?

Answer: Administer a ClusterLearn common tasks for administering a cluster.Administration with kubeadmOverprovision Node Capacity For A ClusterMigrating from dockershimGenerate Certificates ManuallyManage Memory, CPU, and API ResourcesInstall a Network Policy ProviderAccess Clusters Using the Kubernetes APIAdvertise Extended Resources for a NodeAutoscale the DNS Service in a ClusterChange the Access Mode of a PersistentVolume to ReadWriteOncePodChange the default StorageClassSwitching from Polling to CRI Event-based Updates to Container StatusChange the Reclaim Policy of a PersistentVolumeCloud Controller Manager AdministrationConfigure a kubelet image credential providerConfigure Quotas for API ObjectsControl CPU Management Policies on the NodeControl Topology Management Policies on a nodeCustomizing DNS ServiceDebugging DNS ResolutionDeclare Network PolicyDeveloping Cloud Controller ManagerEnable Or Disable A Kubernetes APIEncrypting Confidential Data at RestDecrypt Confidential Data that is Already Encrypted at RestGuaranteed Scheduling For Critical Add-On PodsIP Masquerade Agent User GuideLimit Storage ConsumptionMigrate Replicated Control Plane To Use Cloud Controller ManagerOperating etcd clusters for KubernetesReserve Compute Resources for System DaemonsRunning Kubernetes Node Components as a Non-root UserSafely Drain a NodeSecuring a ClusterSet Kubelet Parameters Via A Configuration FileShare a Cluster with NamespacesUpgrade A ClusterUse Cascading Deletion in a ClusterUsing a KMS provider for data encryptionUsing CoreDNS for Service DiscoveryUsing NodeLocal DNSCache in Kubernetes ClustersUsing sysctls in a Kubernetes ClusterUtilizing the NUMA-aware Memory ManagerVerify Signed Kubernetes Artifacts


Question: What are the benefits of Administer a Cluster?

Answer: Administer a ClusterLearn common tasks for administering a cluster.Administration with kubeadmOverprovision Node Capacity For A ClusterMigrating from dockershimGenerate Certificates ManuallyManage Memory, CPU, and API ResourcesInstall a Network Policy ProviderAccess Clusters Using the Kubernetes APIAdvertise Extended Resources for a NodeAutoscale the DNS Service in a ClusterChange the Access Mode of a PersistentVolume to ReadWriteOncePodChange the default StorageClassSwitching from Polling to CRI Event-based Updates to Container StatusChange the Reclaim Policy of a PersistentVolumeCloud Controller Manager AdministrationConfigure a kubelet image credential providerConfigure Quotas for API ObjectsControl CPU Management Policies on the NodeControl Topology Management Policies on a nodeCustomizing DNS ServiceDebugging DNS ResolutionDeclare Network PolicyDeveloping Cloud Controller ManagerEnable Or Disable A Kubernetes APIEncrypting Confidential Data at RestDecrypt Confidential Data that is Already Encrypted at RestGuaranteed Scheduling For Critical Add-On PodsIP Masquerade Agent User GuideLimit Storage ConsumptionMigrate Replicated Control Plane To Use Cloud Controller ManagerOperating etcd clusters for KubernetesReserve Compute Resources for System DaemonsRunning Kubernetes Node Components as a Non-root UserSafely Drain a NodeSecuring a ClusterSet Kubelet Parameters Via A Configuration FileShare a Cluster with NamespacesUpgrade A ClusterUse Cascading Deletion in a ClusterUsing a KMS provider for data encryptionUsing CoreDNS for Service DiscoveryUsing NodeLocal DNSCache in Kubernetes ClustersUsing sysctls in a Kubernetes ClusterUtilizing the NUMA-aware Memory ManagerVerify Signed Kubernetes Artifacts


Question: What is Considerations for large clusters?

Answer: Considerations for large clustersA cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane. Kubernetes v1.34 supports clusters with up to 5,000 nodes. More specifically, Kubernetes is designed to accommodate configurations that meet all of the following criteria:No more than 110 pods per nodeNo more than 5,000 nodesNo more than 150,000 total podsNo more than 300,000 total containersYou can scale your cluster by adding or removing nodes. The way you do this depends on how your cluster is deployed.Cloud provider resource quotasTo avoid running into cloud provider quota issues, when creating a cluster with many nodes, consider:Requesting a quota increase for cloud resources such as:Computer instancesCPUsStorage volumesIn-use IP addressesPacket filtering rule setsNumber of load balancersNetwork subnetsLog streamsGating the cluster scaling actions to bring up new nodes in batches, with a pause between batches, because some cloud providers rate limit the creation of new instances.Control plane componentsFor a large cluster, you need a control plane with sufficient compute and other resources.Typically you would run one or two control plane instances per failure zone, scaling those instances vertically first and then scaling horizontally after reaching the point of falling returns to (vertical) scale.You should run at least one instance per failure zone to provide fault-tolerance. Kubernetes nodes do not automatically steer traffic towards control-plane endpoints that are in the same failure zone; however, your cloud provider might have its own mechanisms to do this.For example, using a managed load balancer, you configure the load balancer to send traffic that originates from the kubelet and Pods in failure zone A, and direct that traffic only to the control plane hosts that are also in zone A. If a single control-plane host or endpoint failure zone A goes offline, that means that all the control-plane traffic for nodes in zone A is now being sent between zones. Running multiple control plane hosts in each zone makes that outcome less likely.etcd storageTo improve performance of large clusters, you can store Event objects in a separate dedicated etcd instance.When creating a cluster, you can (using custom tooling):start and configure additional etcd instanceconfigure the API server to use it for storing eventsSee Operating etcd clusters for Kubernetes and Set up a High Availability etcd cluster with kubeadm for details on configuring and managing etcd for a large cluster.Addon resourcesKubernetes resource limits help to minimize the impact of memory leaks and other ways that pods and containers can impact on other components. These resource limits apply to addon resources just as they apply to application workloads.For example, you can set CPU and memory limits for a logging component: ... containers: - name: fluentd-cloud-logging image: fluent/fluentd-kubernetes-daemonset:v1 resources: limits: c


Question: How does Considerations for large clusters work?

Answer: Considerations for large clustersA cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane. Kubernetes v1.34 supports clusters with up to 5,000 nodes. More specifically, Kubernetes is designed to accommodate configurations that meet all of the following criteria:No more than 110 pods per nodeNo more than 5,000 nodesNo more than 150,000 total podsNo more than 300,000 total containersYou can scale your cluster by adding or removing nodes. The way you do this depends on how your cluster is deployed.Cloud provider resource quotasTo avoid running into cloud provider quota issues, when creating a cluster with many nodes, consider:Requesting a quota increase for cloud resources such as:Computer instancesCPUsStorage volumesIn-use IP addressesPacket filtering rule setsNumber of load balancersNetwork subnetsLog streamsGating the cluster scaling actions to bring up new nodes in batches, with a pause between batches, because some cloud providers rate limit the creation of new instances.Control plane componentsFor a large cluster, you need a control plane with sufficient compute and other resources.Typically you would run one or two control plane instances per failure zone, scaling those instances vertically first and then scaling horizontally after reaching the point of falling returns to (vertical) scale.You should run at least one instance per failure zone to provide fault-tolerance. Kubernetes nodes do not automatically steer traffic towards control-plane endpoints that are in the same failure zone; however, your cloud provider might have its own mechanisms to do this.For example, using a managed load balancer, you configure the load balancer to send traffic that originates from the kubelet and Pods in failure zone A, and direct that traffic only to the control plane hosts that are also in zone A. If a single control-plane host or endpoint failure zone A goes offline, that means that all the control-plane traffic for nodes in zone A is now being sent between zones. Running multiple control plane hosts in each zone makes that outcome less likely.etcd storageTo improve performance of large clusters, you can store Event objects in a separate dedicated etcd instance.When creating a cluster, you can (using custom tooling):start and configure additional etcd instanceconfigure the API server to use it for storing eventsSee Operating etcd clusters for Kubernetes and Set up a High Availability etcd cluster with kubeadm for details on configuring and managing etcd for a large cluster.Addon resourcesKubernetes resource limits help to minimize the impact of memory leaks and other ways that pods and containers can impact on other components. These resource limits apply to addon resources just as they apply to application workloads.For example, you can set CPU and memory limits for a logging component: ... containers: - name: fluentd-cloud-logging image: fluent/fluentd-kubernetes-daemonset:v1 resources: limits: c


Question: When would you use Considerations for large clusters?

Answer: Considerations for large clustersA cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane. Kubernetes v1.34 supports clusters with up to 5,000 nodes. More specifically, Kubernetes is designed to accommodate configurations that meet all of the following criteria:No more than 110 pods per nodeNo more than 5,000 nodesNo more than 150,000 total podsNo more than 300,000 total containersYou can scale your cluster by adding or removing nodes. The way you do this depends on how your cluster is deployed.Cloud provider resource quotasTo avoid running into cloud provider quota issues, when creating a cluster with many nodes, consider:Requesting a quota increase for cloud resources such as:Computer instancesCPUsStorage volumesIn-use IP addressesPacket filtering rule setsNumber of load balancersNetwork subnetsLog streamsGating the cluster scaling actions to bring up new nodes in batches, with a pause between batches, because some cloud providers rate limit the creation of new instances.Control plane componentsFor a large cluster, you need a control plane with sufficient compute and other resources.Typically you would run one or two control plane instances per failure zone, scaling those instances vertically first and then scaling horizontally after reaching the point of falling returns to (vertical) scale.You should run at least one instance per failure zone to provide fault-tolerance. Kubernetes nodes do not automatically steer traffic towards control-plane endpoints that are in the same failure zone; however, your cloud provider might have its own mechanisms to do this.For example, using a managed load balancer, you configure the load balancer to send traffic that originates from the kubelet and Pods in failure zone A, and direct that traffic only to the control plane hosts that are also in zone A. If a single control-plane host or endpoint failure zone A goes offline, that means that all the control-plane traffic for nodes in zone A is now being sent between zones. Running multiple control plane hosts in each zone makes that outcome less likely.etcd storageTo improve performance of large clusters, you can store Event objects in a separate dedicated etcd instance.When creating a cluster, you can (using custom tooling):start and configure additional etcd instanceconfigure the API server to use it for storing eventsSee Operating etcd clusters for Kubernetes and Set up a High Availability etcd cluster with kubeadm for details on configuring and managing etcd for a large cluster.Addon resourcesKubernetes resource limits help to minimize the impact of memory leaks and other ways that pods and containers can impact on other components. These resource limits apply to addon resources just as they apply to application workloads.For example, you can set CPU and memory limits for a logging component: ... containers: - name: fluentd-cloud-logging image: fluent/fluentd-kubernetes-daemonset:v1 resources: limits: c


Question: What are the benefits of Considerations for large clusters?

Answer: Considerations for large clustersA cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane. Kubernetes v1.34 supports clusters with up to 5,000 nodes. More specifically, Kubernetes is designed to accommodate configurations that meet all of the following criteria:No more than 110 pods per nodeNo more than 5,000 nodesNo more than 150,000 total podsNo more than 300,000 total containersYou can scale your cluster by adding or removing nodes. The way you do this depends on how your cluster is deployed.Cloud provider resource quotasTo avoid running into cloud provider quota issues, when creating a cluster with many nodes, consider:Requesting a quota increase for cloud resources such as:Computer instancesCPUsStorage volumesIn-use IP addressesPacket filtering rule setsNumber of load balancersNetwork subnetsLog streamsGating the cluster scaling actions to bring up new nodes in batches, with a pause between batches, because some cloud providers rate limit the creation of new instances.Control plane componentsFor a large cluster, you need a control plane with sufficient compute and other resources.Typically you would run one or two control plane instances per failure zone, scaling those instances vertically first and then scaling horizontally after reaching the point of falling returns to (vertical) scale.You should run at least one instance per failure zone to provide fault-tolerance. Kubernetes nodes do not automatically steer traffic towards control-plane endpoints that are in the same failure zone; however, your cloud provider might have its own mechanisms to do this.For example, using a managed load balancer, you configure the load balancer to send traffic that originates from the kubelet and Pods in failure zone A, and direct that traffic only to the control plane hosts that are also in zone A. If a single control-plane host or endpoint failure zone A goes offline, that means that all the control-plane traffic for nodes in zone A is now being sent between zones. Running multiple control plane hosts in each zone makes that outcome less likely.etcd storageTo improve performance of large clusters, you can store Event objects in a separate dedicated etcd instance.When creating a cluster, you can (using custom tooling):start and configure additional etcd instanceconfigure the API server to use it for storing eventsSee Operating etcd clusters for Kubernetes and Set up a High Availability etcd cluster with kubeadm for details on configuring and managing etcd for a large cluster.Addon resourcesKubernetes resource limits help to minimize the impact of memory leaks and other ways that pods and containers can impact on other components. These resource limits apply to addon resources just as they apply to application workloads.For example, you can set CPU and memory limits for a logging component: ... containers: - name: fluentd-cloud-logging image: fluent/fluentd-kubernetes-daemonset:v1 resources: limits: c


Question: What is Considerations for large clusters?

Answer: A   c l u s t e r   i s   a   s e t   o f   n o d e s   ( p h y s i c a l   o r   v i r t u a l   m a c h i n e s )   r u n n i n g   K u b e r n e t e s   a g e n t s ,   m a n a g e d   b y   t h e   c o n t r o l   p l a n e .   K u b e r n e t e s   v 1 . 3 4   s u p p o r t s   c l u s t e r s   w i t h   u p   t o   5 , 0 0 0   n o d e s .   M o r e   s p e c i f i c a l l y ,   K u b e r n e t e s   i s   d e s i g n e d   t o   a c c o m m o d a t e   c o n f i g u r a t i o n s   t h a t   m e e t   a l l   o f   t h e   f o l l o w i n g   c r i t e r i a :   N o   m o r e   t h a n   1 1 0   p o d s   p e r   n o d e N o   m o r e   t h a n   5 , 0 0 0   n o d e s N o   m o r e   t h a n   1 5 0 , 0 0 0   t o t a l   p o d s N o   m o r e   t h a n   3 0 0 , 0 0 0   t o t a l   c o n t a i n e r s   Y o u   c a n   s c a l e   y o u r   c l u s t e r   b y   a d d i n g   o r   r e m o v i n g   n o d e s .   T h e   w a y   y o u   d o   t h i s   d e p e n d s   o n   h o w   y o u r   c l u s t e r   i s   d e p l o y e d .


Question: What is Cloud provider resource quotas?

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


Question: What is Control plane components?

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


Question: What is etcd storage?

Answer: T o   i m p r o v e   p e r f o r m a n c e   o f   l a r g e   c l u s t e r s ,   y o u   c a n   s t o r e   E v e n t   o b j e c t s   i n   a   s e p a r a t e   d e d i c a t e d   e t c d   i n s t a n c e .   W h e n   c r e a t i n g   a   c l u s t e r ,   y o u   c a n   ( u s i n g   c u s t o m   t o o l i n g ) :   s t a r t   a n d   c o n f i g u r e   a d d i t i o n a l   e t c d   i n s t a n c e c o n f i g u r e   t h e   A P I   s e r v e r   t o   u s e   i t   f o r   s t o r i n g   e v e n t s   S e e   O p e r a t i n g   e t c d   c l u s t e r s   f o r   K u b e r n e t e s   a n d   S e t   u p   a   H i g h   A v a i l a b i l i t y   e t c d   c l u s t e r   w i t h   k u b e a d m   f o r   d e t a i l s   o n   c o n f i g u r i n g   a n d   m a n a g i n g   e t c d   f o r   a   l a r g e   c l u s t e r .


Question: What is Addon resources?

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


Question: What is What's next?

Answer: V e r t i c a l P o d A u t o s c a l e r   i s   a   c u s t o m   r e s o u r c e   t h a t   y o u   c a n   d e p l o y   i n t o   y o u r   c l u s t e r   t o   h e l p   y o u   m a n a g e   r e s o u r c e   r e q u e s t s   a n d   l i m i t s   f o r   p o d s . L e a r n   m o r e   a b o u t   V e r t i c a l   P o d   A u t o s c a l e r   a n d   h o w   y o u   c a n   u s e   i t   t o   s c a l e   c l u s t e r   c o m p o n e n t s ,   i n c l u d i n g   c l u s t e r - c r i t i c a l   a d d o n s . R e a d   a b o u t   N o d e   a u t o s c a l i n g T h e   a d d o n   r e s i z e r   h e l p s   y o u   i n   r e s i z i n g   t h e   a d d o n s   a u t o m a t i c a l l y   a s   y o u r   c l u s t e r ' s   s c a l e   c h a n g e s .   V e r t i c a l P o d A u t o s c a l e r   i s   a   c u s t o m   r e s o u r c e   t h a t   y o u   c a n   d e p l o y   i n t o   y o u r   c l u s t e r   t o   h e l p   y o u   m a n a g e   r e s o u r c e   r e q u e s t s   a n d   l i m i t s   f o r   p o d s . L e a r n   m o r e   a b o u t   V e r t i c a l   P o d   A u t o s c a l e r   a n d   h o w   y o u   c a n   u s e   i t   t o   s c a l e   c l u s t e r   c o m p o n e n t s ,   i n c l u d i n g   c l u s t e r - c r i t i c a l   a d d o n s .   R e a d   a b o u t   N o d e   a u t o s c a l i n g   T h e   a d d o n   r e s i z e r   h e l p s   y o u   i n   r e s i z i n g   t h e   a d d o n s   a u t o m a t i c a l l y   a s   y o u r   c l u s t e r ' s   s c a l e   c h a n g e s .


Question: What is User Namespaces?

Answer: User NamespacesFEATURE STATE: Kubernetes v1.30 [beta]This page explains how user namespaces are used in Kubernetes pods. A user namespace isolates the user running inside the container from the one in the host.A process running as root in a container can run as a different (non-root) user in the host; in other words, the process has full privileges for operations inside the user namespace, but is unprivileged for operations outside the namespace.You can use this feature to reduce the damage a compromised container can do to the host or other pods in the same node. There are several security vulnerabilities rated either HIGH or CRITICAL that were not exploitable when user namespaces is active. It is expected user namespace will mitigate some future vulnerabilities too.Before you beginNote: 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.This is a Linux-only feature and support is needed in Linux for idmap mounts on the filesystems used. This means:On the node, the filesystem you use for /var/lib/kubelet/pods/, or the custom directory you configure for this, needs idmap mount support.All the filesystems used in the pod's volumes must support idmap mounts.In practice this means you need at least Linux 6.3, as tmpfs started supporting idmap mounts in that version. This is usually needed as several Kubernetes features use tmpfs (the service account token that is mounted by default uses a tmpfs, Secrets use a tmpfs, etc.)Some popular filesystems that support idmap mounts in Linux 6.3 are: btrfs, ext4, xfs, fat, tmpfs, overlayfs.In addition, the container runtime and its underlying OCI runtime must support user namespaces. The following OCI runtimes offer support:crun version 1.9 or greater (it's recommend version 1.13+).runc version 1.2 or greaterNote:Some OCI runtimes do not include the support needed for using user namespaces in Linux pods. If you use a managed Kubernetes, or have downloaded it from packages and set it up, it's possible that nodes in your cluster use a runtime that doesn't include this support.To use user namespaces with Kubernetes, you also need to use a CRI container runtime to use this feature with Kubernetes pods:containerd: version 2.0 (and later) supports user namespaces for containers.CRI-O: version 1.25 (and later) supports user namespaces for containers.You can see the status of user namespaces support in cri-dockerd tracked in an issue on GitHub.IntroductionUser namespaces is a Linux feature that allows to map users in the container to different users in the host. Furthermore, the capabilities granted to a pod in a user namespace are valid only in the namespace and void outside of it.A pod can opt-in to use user namespaces by setting the pod.spec.hostUsers field to false.The kubel


Question: How does User Namespaces work?

Answer: User NamespacesFEATURE STATE: Kubernetes v1.30 [beta]This page explains how user namespaces are used in Kubernetes pods. A user namespace isolates the user running inside the container from the one in the host.A process running as root in a container can run as a different (non-root) user in the host; in other words, the process has full privileges for operations inside the user namespace, but is unprivileged for operations outside the namespace.You can use this feature to reduce the damage a compromised container can do to the host or other pods in the same node. There are several security vulnerabilities rated either HIGH or CRITICAL that were not exploitable when user namespaces is active. It is expected user namespace will mitigate some future vulnerabilities too.Before you beginNote: 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.This is a Linux-only feature and support is needed in Linux for idmap mounts on the filesystems used. This means:On the node, the filesystem you use for /var/lib/kubelet/pods/, or the custom directory you configure for this, needs idmap mount support.All the filesystems used in the pod's volumes must support idmap mounts.In practice this means you need at least Linux 6.3, as tmpfs started supporting idmap mounts in that version. This is usually needed as several Kubernetes features use tmpfs (the service account token that is mounted by default uses a tmpfs, Secrets use a tmpfs, etc.)Some popular filesystems that support idmap mounts in Linux 6.3 are: btrfs, ext4, xfs, fat, tmpfs, overlayfs.In addition, the container runtime and its underlying OCI runtime must support user namespaces. The following OCI runtimes offer support:crun version 1.9 or greater (it's recommend version 1.13+).runc version 1.2 or greaterNote:Some OCI runtimes do not include the support needed for using user namespaces in Linux pods. If you use a managed Kubernetes, or have downloaded it from packages and set it up, it's possible that nodes in your cluster use a runtime that doesn't include this support.To use user namespaces with Kubernetes, you also need to use a CRI container runtime to use this feature with Kubernetes pods:containerd: version 2.0 (and later) supports user namespaces for containers.CRI-O: version 1.25 (and later) supports user namespaces for containers.You can see the status of user namespaces support in cri-dockerd tracked in an issue on GitHub.IntroductionUser namespaces is a Linux feature that allows to map users in the container to different users in the host. Furthermore, the capabilities granted to a pod in a user namespace are valid only in the namespace and void outside of it.A pod can opt-in to use user namespaces by setting the pod.spec.hostUsers field to false.The kubel


Question: When would you use User Namespaces?

Answer: User NamespacesFEATURE STATE: Kubernetes v1.30 [beta]This page explains how user namespaces are used in Kubernetes pods. A user namespace isolates the user running inside the container from the one in the host.A process running as root in a container can run as a different (non-root) user in the host; in other words, the process has full privileges for operations inside the user namespace, but is unprivileged for operations outside the namespace.You can use this feature to reduce the damage a compromised container can do to the host or other pods in the same node. There are several security vulnerabilities rated either HIGH or CRITICAL that were not exploitable when user namespaces is active. It is expected user namespace will mitigate some future vulnerabilities too.Before you beginNote: 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.This is a Linux-only feature and support is needed in Linux for idmap mounts on the filesystems used. This means:On the node, the filesystem you use for /var/lib/kubelet/pods/, or the custom directory you configure for this, needs idmap mount support.All the filesystems used in the pod's volumes must support idmap mounts.In practice this means you need at least Linux 6.3, as tmpfs started supporting idmap mounts in that version. This is usually needed as several Kubernetes features use tmpfs (the service account token that is mounted by default uses a tmpfs, Secrets use a tmpfs, etc.)Some popular filesystems that support idmap mounts in Linux 6.3 are: btrfs, ext4, xfs, fat, tmpfs, overlayfs.In addition, the container runtime and its underlying OCI runtime must support user namespaces. The following OCI runtimes offer support:crun version 1.9 or greater (it's recommend version 1.13+).runc version 1.2 or greaterNote:Some OCI runtimes do not include the support needed for using user namespaces in Linux pods. If you use a managed Kubernetes, or have downloaded it from packages and set it up, it's possible that nodes in your cluster use a runtime that doesn't include this support.To use user namespaces with Kubernetes, you also need to use a CRI container runtime to use this feature with Kubernetes pods:containerd: version 2.0 (and later) supports user namespaces for containers.CRI-O: version 1.25 (and later) supports user namespaces for containers.You can see the status of user namespaces support in cri-dockerd tracked in an issue on GitHub.IntroductionUser namespaces is a Linux feature that allows to map users in the container to different users in the host. Furthermore, the capabilities granted to a pod in a user namespace are valid only in the namespace and void outside of it.A pod can opt-in to use user namespaces by setting the pod.spec.hostUsers field to false.The kubel


Question: What are the benefits of User Namespaces?

Answer: User NamespacesFEATURE STATE: Kubernetes v1.30 [beta]This page explains how user namespaces are used in Kubernetes pods. A user namespace isolates the user running inside the container from the one in the host.A process running as root in a container can run as a different (non-root) user in the host; in other words, the process has full privileges for operations inside the user namespace, but is unprivileged for operations outside the namespace.You can use this feature to reduce the damage a compromised container can do to the host or other pods in the same node. There are several security vulnerabilities rated either HIGH or CRITICAL that were not exploitable when user namespaces is active. It is expected user namespace will mitigate some future vulnerabilities too.Before you beginNote: 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.This is a Linux-only feature and support is needed in Linux for idmap mounts on the filesystems used. This means:On the node, the filesystem you use for /var/lib/kubelet/pods/, or the custom directory you configure for this, needs idmap mount support.All the filesystems used in the pod's volumes must support idmap mounts.In practice this means you need at least Linux 6.3, as tmpfs started supporting idmap mounts in that version. This is usually needed as several Kubernetes features use tmpfs (the service account token that is mounted by default uses a tmpfs, Secrets use a tmpfs, etc.)Some popular filesystems that support idmap mounts in Linux 6.3 are: btrfs, ext4, xfs, fat, tmpfs, overlayfs.In addition, the container runtime and its underlying OCI runtime must support user namespaces. The following OCI runtimes offer support:crun version 1.9 or greater (it's recommend version 1.13+).runc version 1.2 or greaterNote:Some OCI runtimes do not include the support needed for using user namespaces in Linux pods. If you use a managed Kubernetes, or have downloaded it from packages and set it up, it's possible that nodes in your cluster use a runtime that doesn't include this support.To use user namespaces with Kubernetes, you also need to use a CRI container runtime to use this feature with Kubernetes pods:containerd: version 2.0 (and later) supports user namespaces for containers.CRI-O: version 1.25 (and later) supports user namespaces for containers.You can see the status of user namespaces support in cri-dockerd tracked in an issue on GitHub.IntroductionUser namespaces is a Linux feature that allows to map users in the container to different users in the host. Furthermore, the capabilities granted to a pod in a user namespace are valid only in the namespace and void outside of it.A pod can opt-in to use user namespaces by setting the pod.spec.hostUsers field to false.The kubel


Question: What is User Namespaces?

Answer: T h i s   p a g e   e x p l a i n s   h o w   u s e r   n a m e s p a c e s   a r e   u s e d   i n   K u b e r n e t e s   p o d s .   A   u s e r   n a m e s p a c e   i s o l a t e s   t h e   u s e r   r u n n i n g   i n s i d e   t h e   c o n t a i n e r   f r o m   t h e   o n e   i n   t h e   h o s t .   A   p r o c e s s   r u n n i n g   a s   r o o t   i n   a   c o n t a i n e r   c a n   r u n   a s   a   d i f f e r e n t   ( n o n - r o o t )   u s e r   i n   t h e   h o s t ;   i n   o t h e r   w o r d s ,   t h e   p r o c e s s   h a s   f u l l   p r i v i l e g e s   f o r   o p e r a t i o n s   i n s i d e   t h e   u s e r   n a m e s p a c e ,   b u t   i s   u n p r i v i l e g e d   f o r   o p e r a t i o n s   o u t s i d e   t h e   n a m e s p a c e .   Y o u   c a n   u s e   t h i s   f e a t u r e   t o   r e d u c e   t h e   d a m a g e   a   c o m p r o m i s e d   c o n t a i n e r   c a n   d o   t o   t h e   h o s t   o r   o t h e r   p o d s   i n   t h e   s a m e   n o d e .   T h e r e   a r e   s e v e r a l   s e c u r i t y   v u l n e r a b i l i t i e s   r a t e d   e i t h e r   H I G H   o r   C R I T I C A L   t h a t   w e r e   n o t   e x p l o i t a b l e   w h e n   u s e r   n a m e s p a c e s   i s   a c t i v e .   I t   i s   e x p e c t e d   u s e r   n a m e s p a c e   w i l l   m i t i g a t e   s o m e   f u t u r e   v u l n e r a b i l i t i e s   t o o .


Question: What is Before you begin?

Answer: T h i s   i s   a   L i n u x - o n l y   f e a t u r e   a n d   s u p p o r t   i s   n e e d e d   i n   L i n u x   f o r   i d m a p   m o u n t s   o n   t h e   f i l e s y s t e m s   u s e d .   T h i s   m e a n s :   O n   t h e   n o d e ,   t h e   f i l e s y s t e m   y o u   u s e   f o r   / v a r / l i b / k u b e l e t / p o d s / ,   o r   t h e   c u s t o m   d i r e c t o r y   y o u   c o n f i g u r e   f o r   t h i s ,   n e e d s   i d m a p   m o u n t   s u p p o r t . A l l   t h e   f i l e s y s t e m s   u s e d   i n   t h e   p o d ' s   v o l u m e s   m u s t   s u p p o r t   i d m a p   m o u n t s .   I n   p r a c t i c e   t h i s   m e a n s   y o u   n e e d   a t   l e a s t   L i n u x   6 . 3 ,   a s   t m p f s   s t a r t e d   s u p p o r t i n g   i d m a p   m o u n t s   i n   t h a t   v e r s i o n .   T h i s   i s   u s u a l l y   n e e d e d   a s   s e v e r a l   K u b e r n e t e s   f e a t u r e s   u s e   t m p f s   ( t h e   s e r v i c e   a c c o u n t   t o k e n   t h a t   i s   m o u n t e d   b y   d e f a u l t   u s e s   a   t m p f s ,   S e c r e t s   u s e   a   t m p f s ,   e t c . )   S o m e   p o p u l a r   f i l e s y s t e m s   t h a t   s u p p o r t   i d m a p   m o u n t s   i n   L i n u x   6 . 3   a r e :   b t r f s ,   e x t 4 ,   x f s ,   f a t ,   t m p f s ,   o v e r l a y f s .   I n   a d d i t i o n ,   t h e   c o n t a i n e r   r u n t i m e   a n d   i t s   u n d e r l y i n g   O C I   r u n t i m e   m u s t   s u p p o r t   u s e r   n a m e s p a c e s .   T h e   f o l l o w i n g   O C I   r u n t i m e s   o f f e r   s u p p o r t :   c r u n   v e r s i o n   1 . 9   o r   g r e a t e r   ( i t ' s   r e c o m m e n d   v e r s i o n   1 . 1 3 + ) . r u n c   v e r s i o n   1 . 2   o r   g r e a t e r


Question: What is Note:?

Answer: T o   u s e   u s e r   n a m e s p a c e s   w i t h   K u b e r n e t e s ,   y o u   a l s o   n e e d   t o   u s e   a   C R I   c o n t a i n e r   r u n t i m e   t o   u s e   t h i s   f e a t u r e   w i t h   K u b e r n e t e s   p o d s :   c o n t a i n e r d :   v e r s i o n   2 . 0   ( a n d   l a t e r )   s u p p o r t s   u s e r   n a m e s p a c e s   f o r   c o n t a i n e r s . C R I - O :   v e r s i o n   1 . 2 5   ( a n d   l a t e r )   s u p p o r t s   u s e r   n a m e s p a c e s   f o r   c o n t a i n e r s .   Y o u   c a n   s e e   t h e   s t a t u s   o f   u s e r   n a m e s p a c e s   s u p p o r t   i n   c r i - d o c k e r d   t r a c k e d   i n   a n   i s s u e   o n   G i t H u b .


Question: What is Introduction?

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


Question: What is Understanding user namespaces for pods?

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


Question: What is Set up a node to support user namespaces?

Answer: B y   d e f a u l t ,   t h e   k u b e l e t   a s s i g n s   p o d s   U I D s / G I D s   a b o v e   t h e   r a n g e   0 - 6 5 5 3 5 ,   b a s e d   o n   t h e   a s s u m p t i o n   t h a t   t h e   h o s t ' s   f i l e s   a n d   p r o c e s s e s   u s e   U I D s / G I D s   w i t h i n   t h i s   r a n g e ,   w h i c h   i s   s t a n d a r d   f o r   m o s t   L i n u x   d i s t r i b u t i o n s .   T h i s   a p p r o a c h   p r e v e n t s   a n y   o v e r l a p   b e t w e e n   t h e   U I D s / G I D s   o f   t h e   h o s t   a n d   t h o s e   o f   t h e   p o d s .   A v o i d i n g   t h e   o v e r l a p   i s   i m p o r t a n t   t o   m i t i g a t e   t h e   i m p a c t   o f   v u l n e r a b i l i t i e s   s u c h   a s   C V E - 2 0 2 1 - 2 5 7 4 1 ,   w h e r e   a   p o d   c a n   p o t e n t i a l l y   r e a d   a r b i t r a r y   f i l e s   i n   t h e   h o s t .   I f   t h e   U I D s / G I D s   o f   t h e   p o d   a n d   t h e   h o s t   d o n ' t   o v e r l a p ,   i t   i s   l i m i t e d   w h a t   a   p o d   w o u l d   b e   a b l e   t o   d o :   t h e   p o d   U I D / G I D   w o n ' t   m a t c h   t h e   h o s t ' s   f i l e   o w n e r / g r o u p .   T h e   k u b e l e t   c a n   u s e   a   c u s t o m   r a n g e   f o r   u s e r   I D s   a n d   g r o u p   I D s   f o r   p o d s .   T o   c o n f i g u r e   a   c u s t o m   r a n g e ,   t h e   n o d e   n e e d s   t o   h a v e :   A   u s e r   k u b e l e t   i n   t h e   s y s t e m   ( y o u   c a n n o t   u s e   a n y   o t h e r   u s e r n a m e   h e r e ) T h e   b i n a r y   g e t s u b i d s   i n s t a l l e d   ( p a r t   o f   s h a d o w - u t i l s )   a n d   i n   t h e   P A T H   f o r   t h e   k u b e l e t   b i n a r y . A   c o n f i g u r a t i o n   o f   s u b o r d i n a t e   U I D s / G I D s   f o r   t h e   k u b e l e t   u s e r   ( s e e   m a n   5   s u b u i d   a n d   m a n


Question: What is ID count for each of Pods?

Answer: S t a r t i n g   w i t h   K u b e r n e t e s   v 1 . 3 3 ,   t h e   I D   c o u n t   f o r   e a c h   o f   P o d s   c a n   b e   s e t   i n   K u b e l e t C o n f i g u r a t i o n .   a p i V e r s i o n :   k u b e l e t . c o n f i g . k 8 s . i o / v 1 b e t a 1   k i n d :   K u b e l e t C o n f i g u r a t i o n   u s e r N a m e s p a c e s :   i d s P e r P o d :   1 0 4 8 5 7 6   T h e   v a l u e   o f   i d s P e r P o d   ( u i n t 3 2 )   m u s t   b e   a   m u l t i p l e   o f   6 5 5 3 6 .   T h e   d e f a u l t   v a l u e   i s   6 5 5 3 6 .   T h i s   v a l u e   o n l y   a p p l i e s   t o   c o n t a i n e r s   c r e a t e d   a f t e r   t h e   k u b e l e t   w a s   s t a r t e d   w i t h   t h i s   K u b e l e t C o n f i g u r a t i o n .   R u n n i n g   c o n t a i n e r s   a r e   n o t   a f f e c t e d   b y   t h i s   c o n f i g .   I n   K u b e r n e t e s   p r i o r   t o   v 1 . 3 3 ,   t h e   I D   c o u n t   f o r   e a c h   o f   P o d s   w a s   h a r d - c o d e d   t o   6 5 5 3 6 .


Question: What is Integration with Pod security admission checks?

Answer: F o r   L i n u x   P o d s   t h a t   e n a b l e   u s e r   n a m e s p a c e s ,   K u b e r n e t e s   r e l a x e s   t h e   a p p l i c a t i o n   o f   P o d   S e c u r i t y   S t a n d a r d s   i n   a   c o n t r o l l e d   w a y .   T h i s   b e h a v i o r   c a n   b e   c o n t r o l l e d   b y   t h e   f e a t u r e   g a t e   U s e r N a m e s p a c e s P o d S e c u r i t y S t a n d a r d s ,   w h i c h   a l l o w s   a n   e a r l y   o p t - i n   f o r   e n d   u s e r s .   A d m i n s   h a v e   t o   e n s u r e   t h a t   u s e r   n a m e s p a c e s   a r e   e n a b l e d   b y   a l l   n o d e s   w i t h i n   t h e   c l u s t e r   i f   u s i n g   t h e   f e a t u r e   g a t e .   I f   y o u   e n a b l e   t h e   a s s o c i a t e d   f e a t u r e   g a t e   a n d   c r e a t e   a   P o d   t h a t   u s e s   u s e r   n a m e s p a c e s ,   t h e   f o l l o w i n g   f i e l d s   w o n ' t   b e   c o n s t r a i n e d   e v e n   i n   c o n t e x t s   t h a t   e n f o r c e   t h e   B a s e l i n e   o r   R e s t r i c t e d   p o d   s e c u r i t y   s t a n d a r d .   T h i s   b e h a v i o r   d o e s   n o t   p r e s e n t   a   s e c u r i t y   c o n c e r n   b e c a u s e   r o o t   i n s i d e   a   P o d   w i t h   u s e r   n a m e s p a c e s   a c t u a l l y   r e f e r s   t o   t h e   u s e r   i n s i d e   t h e   c o n t a i n e r ,   t h a t   i s   n e v e r   m a p p e d   t o   a   p r i v i l e g e d   u s e r   o n   t h e   h o s t .   H e r e ' s   t h e   l i s t   o f   f i e l d s   t h a t   a r e   n o t   c h e c k s   f o r   P o d s   i n   t h o s e   c i r c u m s t a n c e s :   s p e c . s e c u r i t y C o n t e x t . r u n A s N o n R o o t s p e c . c o n t a i n e r s [ * ] . s e c u r i t y C o n t e x t . r u n A s N o n R o o t s p e c . i n i t C o n t a i n e r s [ * ] . s e c u r i t y C o n t e x t . r u n A s N o n R o o t s p e c . e p h


Question: What is Limitations?

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


Question: What is Metrics and observability?

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


Question: What is What's next?

Answer: T a k e   a   l o o k   a t   U s e   a   U s e r   N a m e s p a c e   W i t h   a   P o d   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 Security For Windows Nodes?

Answer: Security For Windows NodesThis page describes security considerations and best practices specific to the Windows operating system.Protection for Secret data on nodesOn Windows, data from Secrets are written out in clear text onto the node's local storage (as compared to using tmpfs / in-memory filesystems on Linux). As a cluster operator, you should take both of the following additional measures:Use file ACLs to secure the Secrets' file location.Apply volume-level encryption using BitLocker.Container usersRunAsUsername can be specified for Windows Pods or containers to execute the container processes as specific user. This is roughly equivalent to RunAsUser.Windows containers offer two default user accounts, ContainerUser and ContainerAdministrator. The differences between these two user accounts are covered in When to use ContainerAdmin and ContainerUser user accounts within Microsoft's Secure Windows containers documentation.Local users can be added to container images during the container build process.Note:Nano Server based images run as ContainerUser by defaultServer Core based images run as ContainerAdministrator by defaultWindows containers can also run as Active Directory identities by utilizing Group Managed Service AccountsPod-level security isolationLinux-specific pod security context mechanisms (such as SELinux, AppArmor, Seccomp, or custom POSIX capabilities) are not supported on Windows nodes.Privileged containers are not supported on Windows. Instead HostProcess containers can be used on Windows to perform many of the tasks performed by privileged containers on Linux.


Question: How does Security For Windows Nodes work?

Answer: Security For Windows NodesThis page describes security considerations and best practices specific to the Windows operating system.Protection for Secret data on nodesOn Windows, data from Secrets are written out in clear text onto the node's local storage (as compared to using tmpfs / in-memory filesystems on Linux). As a cluster operator, you should take both of the following additional measures:Use file ACLs to secure the Secrets' file location.Apply volume-level encryption using BitLocker.Container usersRunAsUsername can be specified for Windows Pods or containers to execute the container processes as specific user. This is roughly equivalent to RunAsUser.Windows containers offer two default user accounts, ContainerUser and ContainerAdministrator. The differences between these two user accounts are covered in When to use ContainerAdmin and ContainerUser user accounts within Microsoft's Secure Windows containers documentation.Local users can be added to container images during the container build process.Note:Nano Server based images run as ContainerUser by defaultServer Core based images run as ContainerAdministrator by defaultWindows containers can also run as Active Directory identities by utilizing Group Managed Service AccountsPod-level security isolationLinux-specific pod security context mechanisms (such as SELinux, AppArmor, Seccomp, or custom POSIX capabilities) are not supported on Windows nodes.Privileged containers are not supported on Windows. Instead HostProcess containers can be used on Windows to perform many of the tasks performed by privileged containers on Linux.


Question: When would you use Security For Windows Nodes?

Answer: Security For Windows NodesThis page describes security considerations and best practices specific to the Windows operating system.Protection for Secret data on nodesOn Windows, data from Secrets are written out in clear text onto the node's local storage (as compared to using tmpfs / in-memory filesystems on Linux). As a cluster operator, you should take both of the following additional measures:Use file ACLs to secure the Secrets' file location.Apply volume-level encryption using BitLocker.Container usersRunAsUsername can be specified for Windows Pods or containers to execute the container processes as specific user. This is roughly equivalent to RunAsUser.Windows containers offer two default user accounts, ContainerUser and ContainerAdministrator. The differences between these two user accounts are covered in When to use ContainerAdmin and ContainerUser user accounts within Microsoft's Secure Windows containers documentation.Local users can be added to container images during the container build process.Note:Nano Server based images run as ContainerUser by defaultServer Core based images run as ContainerAdministrator by defaultWindows containers can also run as Active Directory identities by utilizing Group Managed Service AccountsPod-level security isolationLinux-specific pod security context mechanisms (such as SELinux, AppArmor, Seccomp, or custom POSIX capabilities) are not supported on Windows nodes.Privileged containers are not supported on Windows. Instead HostProcess containers can be used on Windows to perform many of the tasks performed by privileged containers on Linux.


Question: What are the benefits of Security For Windows Nodes?

Answer: Security For Windows NodesThis page describes security considerations and best practices specific to the Windows operating system.Protection for Secret data on nodesOn Windows, data from Secrets are written out in clear text onto the node's local storage (as compared to using tmpfs / in-memory filesystems on Linux). As a cluster operator, you should take both of the following additional measures:Use file ACLs to secure the Secrets' file location.Apply volume-level encryption using BitLocker.Container usersRunAsUsername can be specified for Windows Pods or containers to execute the container processes as specific user. This is roughly equivalent to RunAsUser.Windows containers offer two default user accounts, ContainerUser and ContainerAdministrator. The differences between these two user accounts are covered in When to use ContainerAdmin and ContainerUser user accounts within Microsoft's Secure Windows containers documentation.Local users can be added to container images during the container build process.Note:Nano Server based images run as ContainerUser by defaultServer Core based images run as ContainerAdministrator by defaultWindows containers can also run as Active Directory identities by utilizing Group Managed Service AccountsPod-level security isolationLinux-specific pod security context mechanisms (such as SELinux, AppArmor, Seccomp, or custom POSIX capabilities) are not supported on Windows nodes.Privileged containers are not supported on Windows. Instead HostProcess containers can be used on Windows to perform many of the tasks performed by privileged containers on Linux.


Question: What is Security For Windows Nodes?

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


Question: What is Protection for Secret data on nodes?

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


Question: What is Container users?

Answer: R u n A s U s e r n a m e   c a n   b e   s p e c i f i e d   f o r   W i n d o w s   P o d s   o r   c o n t a i n e r s   t o   e x e c u t e   t h e   c o n t a i n e r   p r o c e s s e s   a s   s p e c i f i c   u s e r .   T h i s   i s   r o u g h l y   e q u i v a l e n t   t o   R u n A s U s e r .   W i n d o w s   c o n t a i n e r s   o f f e r   t w o   d e f a u l t   u s e r   a c c o u n t s ,   C o n t a i n e r U s e r   a n d   C o n t a i n e r A d m i n i s t r a t o r .   T h e   d i f f e r e n c e s   b e t w e e n   t h e s e   t w o   u s e r   a c c o u n t s   a r e   c o v e r e d   i n   W h e n   t o   u s e   C o n t a i n e r A d m i n   a n d   C o n t a i n e r U s e r   u s e r   a c c o u n t s   w i t h i n   M i c r o s o f t ' s   S e c u r e   W i n d o w s   c o n t a i n e r s   d o c u m e n t a t i o n .   L o c a l   u s e r s   c a n   b e   a d d e d   t o   c o n t a i n e r   i m a g e s   d u r i n g   t h e   c o n t a i n e r   b u i l d   p r o c e s s .


Question: What is Note:?

Answer: N a n o   S e r v e r   b a s e d   i m a g e s   r u n   a s   C o n t a i n e r U s e r   b y   d e f a u l t S e r v e r   C o r e   b a s e d   i m a g e s   r u n   a s   C o n t a i n e r A d m i n i s t r a t o r   b y   d e f a u l t   W i n d o w s   c o n t a i n e r s   c a n   a l s o   r u n   a s   A c t i v e   D i r e c t o r y   i d e n t i t i e s   b y   u t i l i z i n g   G r o u p   M a n a g e d   S e r v i c e   A c c o u n t s


Question: What is Pod-level security isolation?

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


Question: What is Troubleshooting CNI plugin-related errors?

Answer: Troubleshooting CNI plugin-related errorsTo avoid CNI plugin-related errors, verify that you are using or upgrading to a container runtime that has been tested to work correctly with your version of Kubernetes.About the "Incompatible CNI versions" and "Failed to destroy network for sandbox" errorsService issues exist for pod CNI network setup and tear down in containerd v1.6.0-v1.6.3 when the CNI plugins have not been upgraded and/or the CNI config version is not declared in the CNI config files. The containerd team reports, "these issues are resolved in containerd v1.6.4."With containerd v1.6.0-v1.6.3, if you do not upgrade the CNI plugins and/or declare the CNI config version, you might encounter the following "Incompatible CNI versions" or "Failed to destroy network for sandbox" error conditions.Incompatible CNI versions errorIf the version of your CNI plugin does not correctly match the plugin version in the config because the config version is later than the plugin version, the containerd log will likely show an error message on startup of a pod similar to:incompatible CNI versions; config is \"1.0.0\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\"]" To fix this issue, update your CNI plugins and CNI config files.Failed to destroy network for sandbox errorIf the version of the plugin is missing in the CNI plugin config, the pod may run. However, stopping the pod generates an error similar to:ERROR[2022-04-26T00:43:24.518165483Z] StopPodSandbox for "b" failed error="failed to destroy network for sandbox \"bbc85f891eaf060c5a879e27bba9b6b06450210161dfdecfbb2732959fb6500a\": invalid version \"\": the version is empty" This error leaves the pod in the not-ready state with a network namespace still attached. To recover from this problem, edit the CNI config file to add the missing version information. The next attempt to stop the pod should be successful.Updating your CNI plugins and CNI config filesIf you're using containerd v1.6.0-v1.6.3 and encountered "Incompatible CNI versions" or "Failed to destroy network for sandbox" errors, consider updating your CNI plugins and editing the CNI config files.Here's an overview of the typical steps for each node:Safely drain and cordon the node.After stopping your container runtime and kubelet services, perform the following upgrade operations:If you're running CNI plugins, upgrade them to the latest version.If you're using non-CNI plugins, replace them with CNI plugins. Use the latest version of the plugins.Update the plugin configuration file to specify or match a version of the CNI specification that the plugin supports, as shown in the following "An example containerd configuration file" section.For containerd, ensure that you have installed the latest version (v1.0.0 or later) of the CNI loopback plugin.Upgrade node components (for example, the kubelet) to Kubernetes v1.24Upgrade to or install the most current version of the container runtime.Bring the node back into your cluster b


Question: How does Troubleshooting CNI plugin-related errors work?

Answer: Troubleshooting CNI plugin-related errorsTo avoid CNI plugin-related errors, verify that you are using or upgrading to a container runtime that has been tested to work correctly with your version of Kubernetes.About the "Incompatible CNI versions" and "Failed to destroy network for sandbox" errorsService issues exist for pod CNI network setup and tear down in containerd v1.6.0-v1.6.3 when the CNI plugins have not been upgraded and/or the CNI config version is not declared in the CNI config files. The containerd team reports, "these issues are resolved in containerd v1.6.4."With containerd v1.6.0-v1.6.3, if you do not upgrade the CNI plugins and/or declare the CNI config version, you might encounter the following "Incompatible CNI versions" or "Failed to destroy network for sandbox" error conditions.Incompatible CNI versions errorIf the version of your CNI plugin does not correctly match the plugin version in the config because the config version is later than the plugin version, the containerd log will likely show an error message on startup of a pod similar to:incompatible CNI versions; config is \"1.0.0\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\"]" To fix this issue, update your CNI plugins and CNI config files.Failed to destroy network for sandbox errorIf the version of the plugin is missing in the CNI plugin config, the pod may run. However, stopping the pod generates an error similar to:ERROR[2022-04-26T00:43:24.518165483Z] StopPodSandbox for "b" failed error="failed to destroy network for sandbox \"bbc85f891eaf060c5a879e27bba9b6b06450210161dfdecfbb2732959fb6500a\": invalid version \"\": the version is empty" This error leaves the pod in the not-ready state with a network namespace still attached. To recover from this problem, edit the CNI config file to add the missing version information. The next attempt to stop the pod should be successful.Updating your CNI plugins and CNI config filesIf you're using containerd v1.6.0-v1.6.3 and encountered "Incompatible CNI versions" or "Failed to destroy network for sandbox" errors, consider updating your CNI plugins and editing the CNI config files.Here's an overview of the typical steps for each node:Safely drain and cordon the node.After stopping your container runtime and kubelet services, perform the following upgrade operations:If you're running CNI plugins, upgrade them to the latest version.If you're using non-CNI plugins, replace them with CNI plugins. Use the latest version of the plugins.Update the plugin configuration file to specify or match a version of the CNI specification that the plugin supports, as shown in the following "An example containerd configuration file" section.For containerd, ensure that you have installed the latest version (v1.0.0 or later) of the CNI loopback plugin.Upgrade node components (for example, the kubelet) to Kubernetes v1.24Upgrade to or install the most current version of the container runtime.Bring the node back into your cluster b


Question: When would you use Troubleshooting CNI plugin-related errors?

Answer: Troubleshooting CNI plugin-related errorsTo avoid CNI plugin-related errors, verify that you are using or upgrading to a container runtime that has been tested to work correctly with your version of Kubernetes.About the "Incompatible CNI versions" and "Failed to destroy network for sandbox" errorsService issues exist for pod CNI network setup and tear down in containerd v1.6.0-v1.6.3 when the CNI plugins have not been upgraded and/or the CNI config version is not declared in the CNI config files. The containerd team reports, "these issues are resolved in containerd v1.6.4."With containerd v1.6.0-v1.6.3, if you do not upgrade the CNI plugins and/or declare the CNI config version, you might encounter the following "Incompatible CNI versions" or "Failed to destroy network for sandbox" error conditions.Incompatible CNI versions errorIf the version of your CNI plugin does not correctly match the plugin version in the config because the config version is later than the plugin version, the containerd log will likely show an error message on startup of a pod similar to:incompatible CNI versions; config is \"1.0.0\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\"]" To fix this issue, update your CNI plugins and CNI config files.Failed to destroy network for sandbox errorIf the version of the plugin is missing in the CNI plugin config, the pod may run. However, stopping the pod generates an error similar to:ERROR[2022-04-26T00:43:24.518165483Z] StopPodSandbox for "b" failed error="failed to destroy network for sandbox \"bbc85f891eaf060c5a879e27bba9b6b06450210161dfdecfbb2732959fb6500a\": invalid version \"\": the version is empty" This error leaves the pod in the not-ready state with a network namespace still attached. To recover from this problem, edit the CNI config file to add the missing version information. The next attempt to stop the pod should be successful.Updating your CNI plugins and CNI config filesIf you're using containerd v1.6.0-v1.6.3 and encountered "Incompatible CNI versions" or "Failed to destroy network for sandbox" errors, consider updating your CNI plugins and editing the CNI config files.Here's an overview of the typical steps for each node:Safely drain and cordon the node.After stopping your container runtime and kubelet services, perform the following upgrade operations:If you're running CNI plugins, upgrade them to the latest version.If you're using non-CNI plugins, replace them with CNI plugins. Use the latest version of the plugins.Update the plugin configuration file to specify or match a version of the CNI specification that the plugin supports, as shown in the following "An example containerd configuration file" section.For containerd, ensure that you have installed the latest version (v1.0.0 or later) of the CNI loopback plugin.Upgrade node components (for example, the kubelet) to Kubernetes v1.24Upgrade to or install the most current version of the container runtime.Bring the node back into your cluster b


Question: What are the benefits of Troubleshooting CNI plugin-related errors?

Answer: Troubleshooting CNI plugin-related errorsTo avoid CNI plugin-related errors, verify that you are using or upgrading to a container runtime that has been tested to work correctly with your version of Kubernetes.About the "Incompatible CNI versions" and "Failed to destroy network for sandbox" errorsService issues exist for pod CNI network setup and tear down in containerd v1.6.0-v1.6.3 when the CNI plugins have not been upgraded and/or the CNI config version is not declared in the CNI config files. The containerd team reports, "these issues are resolved in containerd v1.6.4."With containerd v1.6.0-v1.6.3, if you do not upgrade the CNI plugins and/or declare the CNI config version, you might encounter the following "Incompatible CNI versions" or "Failed to destroy network for sandbox" error conditions.Incompatible CNI versions errorIf the version of your CNI plugin does not correctly match the plugin version in the config because the config version is later than the plugin version, the containerd log will likely show an error message on startup of a pod similar to:incompatible CNI versions; config is \"1.0.0\", plugin supports [\"0.1.0\" \"0.2.0\" \"0.3.0\" \"0.3.1\" \"0.4.0\"]" To fix this issue, update your CNI plugins and CNI config files.Failed to destroy network for sandbox errorIf the version of the plugin is missing in the CNI plugin config, the pod may run. However, stopping the pod generates an error similar to:ERROR[2022-04-26T00:43:24.518165483Z] StopPodSandbox for "b" failed error="failed to destroy network for sandbox \"bbc85f891eaf060c5a879e27bba9b6b06450210161dfdecfbb2732959fb6500a\": invalid version \"\": the version is empty" This error leaves the pod in the not-ready state with a network namespace still attached. To recover from this problem, edit the CNI config file to add the missing version information. The next attempt to stop the pod should be successful.Updating your CNI plugins and CNI config filesIf you're using containerd v1.6.0-v1.6.3 and encountered "Incompatible CNI versions" or "Failed to destroy network for sandbox" errors, consider updating your CNI plugins and editing the CNI config files.Here's an overview of the typical steps for each node:Safely drain and cordon the node.After stopping your container runtime and kubelet services, perform the following upgrade operations:If you're running CNI plugins, upgrade them to the latest version.If you're using non-CNI plugins, replace them with CNI plugins. Use the latest version of the plugins.Update the plugin configuration file to specify or match a version of the CNI specification that the plugin supports, as shown in the following "An example containerd configuration file" section.For containerd, ensure that you have installed the latest version (v1.0.0 or later) of the CNI loopback plugin.Upgrade node components (for example, the kubelet) to Kubernetes v1.24Upgrade to or install the most current version of the container runtime.Bring the node back into your cluster b


Question: What is Troubleshooting CNI plugin-related errors?

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


Question: What is About the "Incompatible CNI versions" and "Failed to destroy network for sandbox" errors?

Answer: S e r v i c e   i s s u e s   e x i s t   f o r   p o d   C N I   n e t w o r k   s e t u p   a n d   t e a r   d o w n   i n   c o n t a i n e r d   v 1 . 6 . 0 - v 1 . 6 . 3   w h e n   t h e   C N I   p l u g i n s   h a v e   n o t   b e e n   u p g r a d e d   a n d / o r   t h e   C N I   c o n f i g   v e r s i o n   i s   n o t   d e c l a r e d   i n   t h e   C N I   c o n f i g   f i l e s .   T h e   c o n t a i n e r d   t e a m   r e p o r t s ,   " t h e s e   i s s u e s   a r e   r e s o l v e d   i n   c o n t a i n e r d   v 1 . 6 . 4 . "   W i t h   c o n t a i n e r d   v 1 . 6 . 0 - v 1 . 6 . 3 ,   i f   y o u   d o   n o t   u p g r a d e   t h e   C N I   p l u g i n s   a n d / o r   d e c l a r e   t h e   C N I   c o n f i g   v e r s i o n ,   y o u   m i g h t   e n c o u n t e r   t h e   f o l l o w i n g   " I n c o m p a t i b l e   C N I   v e r s i o n s "   o r   " F a i l e d   t o   d e s t r o y   n e t w o r k   f o r   s a n d b o x "   e r r o r   c o n d i t i o n s .


Question: What is Incompatible CNI versions error?

Answer: I f   t h e   v e r s i o n   o f   y o u r   C N I   p l u g i n   d o e s   n o t   c o r r e c t l y   m a t c h   t h e   p l u g i n   v e r s i o n   i n   t h e   c o n f i g   b e c a u s e   t h e   c o n f i g   v e r s i o n   i s   l a t e r   t h a n   t h e   p l u g i n   v e r s i o n ,   t h e   c o n t a i n e r d   l o g   w i l l   l i k e l y   s h o w   a n   e r r o r   m e s s a g e   o n   s t a r t u p   o f   a   p o d   s i m i l a r   t o :   i n c o m p a t i b l e   C N I   v e r s i o n s ;   c o n f i g   i s   \ " 1 . 0 . 0 \ " ,   p l u g i n   s u p p o r t s   [ \ " 0 . 1 . 0 \ "   \ " 0 . 2 . 0 \ "   \ " 0 . 3 . 0 \ "   \ " 0 . 3 . 1 \ "   \ " 0 . 4 . 0 \ " ] "   T o   f i x   t h i s   i s s u e ,   u p d a t e   y o u r   C N I   p l u g i n s   a n d   C N I   c o n f i g   f i l e s .


Question: What is Failed to destroy network for sandbox error?

Answer: I f   t h e   v e r s i o n   o f   t h e   p l u g i n   i s   m i s s i n g   i n   t h e   C N I   p l u g i n   c o n f i g ,   t h e   p o d   m a y   r u n .   H o w e v e r ,   s t o p p i n g   t h e   p o d   g e n e r a t e s   a n   e r r o r   s i m i l a r   t o :   E R R O R [ 2 0 2 2 - 0 4 - 2 6 T 0 0 : 4 3 : 2 4 . 5 1 8 1 6 5 4 8 3 Z ]   S t o p P o d S a n d b o x   f o r   " b "   f a i l e d   e r r o r = " f a i l e d   t o   d e s t r o y   n e t w o r k   f o r   s a n d b o x   \ " b b c 8 5 f 8 9 1 e a f 0 6 0 c 5 a 8 7 9 e 2 7 b b a 9 b 6 b 0 6 4 5 0 2 1 0 1 6 1 d f d e c f b b 2 7 3 2 9 5 9 f b 6 5 0 0 a \ " :   i n v a l i d   v e r s i o n   \ " \ " :   t h e   v e r s i o n   i s   e m p t y "   T h i s   e r r o r   l e a v e s   t h e   p o d   i n   t h e   n o t - r e a d y   s t a t e   w i t h   a   n e t w o r k   n a m e s p a c e   s t i l l   a t t a c h e d .   T o   r e c o v e r   f r o m   t h i s   p r o b l e m ,   e d i t   t h e   C N I   c o n f i g   f i l e   t o   a d d   t h e   m i s s i n g   v e r s i o n   i n f o r m a t i o n .   T h e   n e x t   a t t e m p t   t o   s t o p   t h e   p o d   s h o u l d   b e   s u c c e s s f u l .


Question: What is Updating your CNI plugins and CNI config files?

Answer: I f   y o u ' r e   u s i n g   c o n t a i n e r d   v 1 . 6 . 0 - v 1 . 6 . 3   a n d   e n c o u n t e r e d   " I n c o m p a t i b l e   C N I   v e r s i o n s "   o r   " F a i l e d   t o   d e s t r o y   n e t w o r k   f o r   s a n d b o x "   e r r o r s ,   c o n s i d e r   u p d a t i n g   y o u r   C N I   p l u g i n s   a n d   e d i t i n g   t h e   C N I   c o n f i g   f i l e s .   H e r e ' s   a n   o v e r v i e w   o f   t h e   t y p i c a l   s t e p s   f o r   e a c h   n o d e :   S a f e l y   d r a i n   a n d   c o r d o n   t h e   n o d e . A f t e r   s t o p p i n g   y o u r   c o n t a i n e r   r u n t i m e   a n d   k u b e l e t   s e r v i c e s ,   p e r f o r m   t h e   f o l l o w i n g   u p g r a d e   o p e r a t i o n s : I f   y o u ' r e   r u n n i n g   C N I   p l u g i n s ,   u p g r a d e   t h e m   t o   t h e   l a t e s t   v e r s i o n . I f   y o u ' r e   u s i n g   n o n - C N I   p l u g i n s ,   r e p l a c e   t h e m   w i t h   C N I   p l u g i n s .   U s e   t h e   l a t e s t   v e r s i o n   o f   t h e   p l u g i n s . U p d a t e   t h e   p l u g i n   c o n f i g u r a t i o n   f i l e   t o   s p e c i f y   o r   m a t c h   a   v e r s i o n   o f   t h e   C N I   s p e c i f i c a t i o n   t h a t   t h e   p l u g i n   s u p p o r t s ,   a s   s h o w n   i n   t h e   f o l l o w i n g   " A n   e x a m p l e   c o n t a i n e r d   c o n f i g u r a t i o n   f i l e "   s e c t i o n . F o r   c o n t a i n e r d ,   e n s u r e   t h a t   y o u   h a v e   i n s t a l l e d   t h e   l a t e s t   v e r s i o n   ( v 1 . 0 . 0   o r   l a t e r )   o f   t h e   C N I   l o o p b a c k   p l u g i n . U p g r a d e   n o d e   c o m p o n e n t s   ( f o r   e x a m p l e ,   t h e   k u b e l e t )   t o   K u b e r n e t e s   v 1 . 2 4 U p g r a d e   t o   o r   i n s t a l l   t h e   m o s t   c u r r e n t   v e r s i o n   o f   t h e   c o n t a i n e


Question: What is An example containerd configuration file?

Answer: T h e   f o l l o w i n g   e x a m p l e   s h o w s   a   c o n f i g u r a t i o n   f o r   c o n t a i n e r d   r u n t i m e   v 1 . 6 . x ,   w h i c h   s u p p o r t s   a   r e c e n t   v e r s i o n   o f   t h e   C N I   s p e c i f i c a t i o n   ( v 1 . 0 . 0 ) .   P l e a s e   s e e   t h e   d o c u m e n t a t i o n   f r o m   y o u r   p l u g i n   a n d   n e t w o r k i n g   p r o v i d e r   f o r   f u r t h e r   i n s t r u c t i o n s   o n   c o n f i g u r i n g   y o u r   s y s t e m .   O n   K u b e r n e t e s ,   c o n t a i n e r d   r u n t i m e   a d d s   a   l o o p b a c k   i n t e r f a c e ,   l o ,   t o   p o d s   a s   a   d e f a u l t   b e h a v i o r .   T h e   c o n t a i n e r d   r u n t i m e   c o n f i g u r e s   t h e   l o o p b a c k   i n t e r f a c e   v i a   a   C N I   p l u g i n ,   l o o p b a c k .   T h e   l o o p b a c k   p l u g i n   i s   d i s t r i b u t e d   a s   p a r t   o f   t h e   c o n t a i n e r d   r e l e a s e   p a c k a g e s   t h a t   h a v e   t h e   c n i   d e s i g n a t i o n .   c o n t a i n e r d   v 1 . 6 . 0   a n d   l a t e r   i n c l u d e s   a   C N I   v 1 . 0 . 0 - c o m p a t i b l e   l o o p b a c k   p l u g i n   a s   w e l l   a s   o t h e r   d e f a u l t   C N I   p l u g i n s .   T h e   c o n f i g u r a t i o n   f o r   t h e   l o o p b a c k   p l u g i n   i s   d o n e   i n t e r n a l l y   b y   c o n t a i n e r d ,   a n d   i s   s e t   t o   u s e   C N I   v 1 . 0 . 0 .   T h i s   a l s o   m e a n s   t h a t   t h e   v e r s i o n   o f   t h e   l o o p b a c k   p l u g i n   m u s t   b e   v 1 . 0 . 0   o r   l a t e r   w h e n   t h i s   n e w e r   v e r s i o n   c o n t a i n e r d   i s   s t a r t e d .   T h e   f o l l o w i n g   b a s h   c o m m a n d   g e n e r a t e s   a n   e x a m p l e   C N I   c o n f i g .   H e r e ,   t h e   1 . 0 . 0   v a l u e   f o r   t h e   c o n f i g


Question: What is Indexed Job for Parallel Processing with Static Work Assignment?

Answer: Indexed Job for Parallel Processing with Static Work AssignmentFEATURE STATE: Kubernetes v1.24 [stable]In this example, you will run a Kubernetes Job that uses multiple parallel worker processes. Each worker is a different container running in its own Pod. The Pods have an index number that the control plane sets automatically, which allows each Pod to identify which part of the overall task to work on.The pod index is available in the annotation batch.kubernetes.io/job-completion-index as a string representing its decimal value. In order for the containerized task process to obtain this index, you can publish the value of the annotation using the downward API mechanism. For convenience, the control plane automatically sets the downward API to expose the index in the JOB_COMPLETION_INDEX environment variable.Here is an overview of the steps in this example:Define a Job manifest using indexed completion. The downward API allows you to pass the pod index annotation as an environment variable or file to the container.Start an Indexed Job based on that manifest.Before you beginYou should already be familiar with the basic, non-parallel, use of Job.You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour Kubernetes server must be at or later than version v1.21.To check the version, enter kubectl version.Choose an approachTo access the work item from the worker program, you have a few options:Read the JOB_COMPLETION_INDEX environment variable. The Job controller automatically links this variable to the annotation containing the completion index.Read a file that contains the completion index.Assuming that you can't modify the program, you can wrap it with a script that reads the index using any of the methods above and converts it into something that the program can use as input.For this example, imagine that you chose option 3 and you want to run the rev utility. This program accepts a file as an argument and prints its content reversed.rev data.txt You'll use the rev tool from the busybox container image.As this is only an example, each Pod only does a tiny piece of work (reversing a short string). In a real workload you might, for example, create a Job that represents the task of producing 60 seconds of video based on scene data. Each work item in the video rendering Job would be to render a particular frame of that video clip. Indexed completion would mean that each Pod in the Job knows which frame to render and publish, by counting frames from the start of the clip.Define an Indexed JobHere is a sample Job manifest that uses Indexed completion mode:application/job/indexed-job.yaml api


Question: How does Indexed Job for Parallel Processing with Static Work Assignment work?

Answer: Indexed Job for Parallel Processing with Static Work AssignmentFEATURE STATE: Kubernetes v1.24 [stable]In this example, you will run a Kubernetes Job that uses multiple parallel worker processes. Each worker is a different container running in its own Pod. The Pods have an index number that the control plane sets automatically, which allows each Pod to identify which part of the overall task to work on.The pod index is available in the annotation batch.kubernetes.io/job-completion-index as a string representing its decimal value. In order for the containerized task process to obtain this index, you can publish the value of the annotation using the downward API mechanism. For convenience, the control plane automatically sets the downward API to expose the index in the JOB_COMPLETION_INDEX environment variable.Here is an overview of the steps in this example:Define a Job manifest using indexed completion. The downward API allows you to pass the pod index annotation as an environment variable or file to the container.Start an Indexed Job based on that manifest.Before you beginYou should already be familiar with the basic, non-parallel, use of Job.You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour Kubernetes server must be at or later than version v1.21.To check the version, enter kubectl version.Choose an approachTo access the work item from the worker program, you have a few options:Read the JOB_COMPLETION_INDEX environment variable. The Job controller automatically links this variable to the annotation containing the completion index.Read a file that contains the completion index.Assuming that you can't modify the program, you can wrap it with a script that reads the index using any of the methods above and converts it into something that the program can use as input.For this example, imagine that you chose option 3 and you want to run the rev utility. This program accepts a file as an argument and prints its content reversed.rev data.txt You'll use the rev tool from the busybox container image.As this is only an example, each Pod only does a tiny piece of work (reversing a short string). In a real workload you might, for example, create a Job that represents the task of producing 60 seconds of video based on scene data. Each work item in the video rendering Job would be to render a particular frame of that video clip. Indexed completion would mean that each Pod in the Job knows which frame to render and publish, by counting frames from the start of the clip.Define an Indexed JobHere is a sample Job manifest that uses Indexed completion mode:application/job/indexed-job.yaml api


Question: When would you use Indexed Job for Parallel Processing with Static Work Assignment?

Answer: Indexed Job for Parallel Processing with Static Work AssignmentFEATURE STATE: Kubernetes v1.24 [stable]In this example, you will run a Kubernetes Job that uses multiple parallel worker processes. Each worker is a different container running in its own Pod. The Pods have an index number that the control plane sets automatically, which allows each Pod to identify which part of the overall task to work on.The pod index is available in the annotation batch.kubernetes.io/job-completion-index as a string representing its decimal value. In order for the containerized task process to obtain this index, you can publish the value of the annotation using the downward API mechanism. For convenience, the control plane automatically sets the downward API to expose the index in the JOB_COMPLETION_INDEX environment variable.Here is an overview of the steps in this example:Define a Job manifest using indexed completion. The downward API allows you to pass the pod index annotation as an environment variable or file to the container.Start an Indexed Job based on that manifest.Before you beginYou should already be familiar with the basic, non-parallel, use of Job.You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour Kubernetes server must be at or later than version v1.21.To check the version, enter kubectl version.Choose an approachTo access the work item from the worker program, you have a few options:Read the JOB_COMPLETION_INDEX environment variable. The Job controller automatically links this variable to the annotation containing the completion index.Read a file that contains the completion index.Assuming that you can't modify the program, you can wrap it with a script that reads the index using any of the methods above and converts it into something that the program can use as input.For this example, imagine that you chose option 3 and you want to run the rev utility. This program accepts a file as an argument and prints its content reversed.rev data.txt You'll use the rev tool from the busybox container image.As this is only an example, each Pod only does a tiny piece of work (reversing a short string). In a real workload you might, for example, create a Job that represents the task of producing 60 seconds of video based on scene data. Each work item in the video rendering Job would be to render a particular frame of that video clip. Indexed completion would mean that each Pod in the Job knows which frame to render and publish, by counting frames from the start of the clip.Define an Indexed JobHere is a sample Job manifest that uses Indexed completion mode:application/job/indexed-job.yaml api


Question: What are the benefits of Indexed Job for Parallel Processing with Static Work Assignment?

Answer: Indexed Job for Parallel Processing with Static Work AssignmentFEATURE STATE: Kubernetes v1.24 [stable]In this example, you will run a Kubernetes Job that uses multiple parallel worker processes. Each worker is a different container running in its own Pod. The Pods have an index number that the control plane sets automatically, which allows each Pod to identify which part of the overall task to work on.The pod index is available in the annotation batch.kubernetes.io/job-completion-index as a string representing its decimal value. In order for the containerized task process to obtain this index, you can publish the value of the annotation using the downward API mechanism. For convenience, the control plane automatically sets the downward API to expose the index in the JOB_COMPLETION_INDEX environment variable.Here is an overview of the steps in this example:Define a Job manifest using indexed completion. The downward API allows you to pass the pod index annotation as an environment variable or file to the container.Start an Indexed Job based on that manifest.Before you beginYou should already be familiar with the basic, non-parallel, use of Job.You need to have a Kubernetes cluster, and the kubectl command-line tool must be configured to communicate with your cluster. It is recommended to run this tutorial on a cluster with at least two nodes that are not acting as control plane hosts. If you do not already have a cluster, you can create one by using minikube or you can use one of these Kubernetes playgrounds:iximiuz LabsKillercodaKodeKloudPlay with KubernetesYour Kubernetes server must be at or later than version v1.21.To check the version, enter kubectl version.Choose an approachTo access the work item from the worker program, you have a few options:Read the JOB_COMPLETION_INDEX environment variable. The Job controller automatically links this variable to the annotation containing the completion index.Read a file that contains the completion index.Assuming that you can't modify the program, you can wrap it with a script that reads the index using any of the methods above and converts it into something that the program can use as input.For this example, imagine that you chose option 3 and you want to run the rev utility. This program accepts a file as an argument and prints its content reversed.rev data.txt You'll use the rev tool from the busybox container image.As this is only an example, each Pod only does a tiny piece of work (reversing a short string). In a real workload you might, for example, create a Job that represents the task of producing 60 seconds of video based on scene data. Each work item in the video rendering Job would be to render a particular frame of that video clip. Indexed completion would mean that each Pod in the Job knows which frame to render and publish, by counting frames from the start of the clip.Define an Indexed JobHere is a sample Job manifest that uses Indexed completion mode:application/job/indexed-job.yaml api


Question: What is Indexed Job for Parallel Processing with Static Work Assignment?

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