📝 k8s cheatsheet

Some useful commands

using kind?

in you mac? with podman?

podman machine init
podman machine start;
export KIND_EXPERIMENTAL_PROVIDER=podman;
kind create cluster

Describe Cluster

• Check version

  % k version  # what do you think it does? :)
  *Client Version: v1.28.3
  Kustomize Version: v5.0.4-0.20230601165947-6ce0bf390ce3
  Server Version: v1.29.2*
  

• Check cluster status

  % k get componentstatuses # will be deprectated
  Warning: v1 ComponentStatus is deprecated in v1.19+
  NAME                 STATUS    MESSAGE   ERROR
  controller-manager   Healthy   ok
  scheduler            Healthy   ok
  etcd-0               Healthy   ok
  

  or talk directly to the endpoint

  % k get --raw='/readyz?verbose'
  [+]ping ok
  [+]log ok
  [+]etcd ok
  [+]etcd-readiness ok
  [+]informer-sync ok
   # more messages
   readyz check passed
  

• List k8s nodes

  % k get nodes
  NAME                 STATUS     ROLES           AGE   VERSION
  kind-control-plane   Ready   control-plane   13s   v1.29.2
  node01               Ready   <none>          13s   v1.29.2
  

  In k8s nodes are separated into control-panel nodes, like the API server, scheduler, etc. which manage the cluster, and worker nodes where your containers will run.

• Get more information about a specific node (prints bunch of info)

  % k describe nodes kind-control-plane
  

  more info on the ouput here

• See the proxies if they are under the API object named DaemonSet

  % k get daemonSets --namespace=kube-system kube-proxy
  

• See DNS k8s deployment

  % k get deployments --namespace=kube-system coredns
  

• Wait for nodes to be ready

  % k wait --for=condition=Ready nodes --all
  node/node1 condition met
  node/node2 condition met
  ...
  

Manage your context

• Change namespace for current context

  % kubectl config set-context --current --namespace=<some ns>