The architectural concepts behind Kubernetes.

Kubernetes is an open source container orchestration engine for automating deployment, scaling, and management of containerized applications. The open source project is hosted by the Cloud Native Computing Foundation.

On Linux, control groups constrain resources that are allocated to processes. The kubelet and the underlying container runtime need to interface with cgroups to enforce resource management for pods and containers which includes cpu/memory requests and limits for containerized workloads. There are two versions of cgroups in Linux: cgroup v1 and cgroup v2. cgroup v2 is the new generation of the cgroup API. What is cgroup v2? FEATURE STATE: Kubernetes v1.

Synopsis Show the status of the rollout. By default 'rollout status' will watch the status of the latest rollout until it's done. If you don't want to wait for the rollout to finish then you can use --watch=false. Note that if a new rollout starts in-between, then 'rollout status' will continue watching the latest revision. If you want to pin to a specific revision and abort if it is rolled over by another revision, use --revision=N where N is the revision you need to watch for.

Synopsis Display resource (CPU/memory) usage of nodes. The top-node command allows you to see the resource consumption of nodes. kubectl top node [NAME | -l label] Examples # Show metrics for all nodes kubectl top node # Show metrics for a given node kubectl top node NODE_NAME Options -h, --help help for node --no-headers If present, print output without headers -l, --selector string Selector (label query) to filter on, supports '=', '==', '!

Synopsis Create a role with single rule. kubectl create role NAME --verb=verb --resource=resource.group/subresource [--resource-name=resourcename] [--dry-run=server|client|none] Examples # Create a role named "pod-reader" that allows user to perform "get", "watch" and "list" on pods kubectl create role pod-reader --verb=get --verb=list --verb=watch --resource=pods # Create a role named "pod-reader" with ResourceName specified kubectl create role pod-reader --verb=get --resource=pods --resource-name=readablepod --resource-name=anotherpod # Create a role named "foo" with API Group specified kubectl create role foo --verb=get,list,watch --resource=rs.

Production-Grade Container Orchestration

You can use the Kubernetes command line tool kubectl to interact with the API Server. Using kubectl is straightforward if you are familiar with the Docker command line tool. However, there are a few differences between the Docker commands and the kubectl commands. The following sections show a Docker sub-command and describe the equivalent kubectl command. docker run To run an nginx Deployment and expose the Deployment, see kubectl create deployment.

Production-Grade Container Orchestration

Synopsis Update environment variables on a pod template. List environment variable definitions in one or more pods, pod templates. Add, update, or remove container environment variable definitions in one or more pod templates (within replication controllers or deployment configurations). View or modify the environment variable definitions on all containers in the specified pods or pod templates, or just those that match a wildcard. If "--env -" is passed, environment variables can be read from STDIN using the standard env syntax.