Kubernetes

These are currently specific to kubectl and there are tons more here.

Set up short names for contexts

• Open ~/.kube.config
• Modify contexts section:

contexts:
- context:
    cluster: cluster1
    user: cluster1
  name: dev
- context:
    cluster: cluster2
    namespace: namespace1
    user: cluster2
  name: namespace1
- context:
    cluster: cluster3
    namespace: db
    user: cluster3
  name: prod
current-context: prod

Just use Click

Here. From here.

Just use K9s

Here.

Use specific context (i.e. cluster)

kubectl config use-context <context>

List namespaces

kubectl get ns

Set namespace

This will also update the relevant context’s namespace value in the ~/.kube/config file.

kubectl config set-context --current --namespace=<namespace>

List everything

This doesn’t actually list everything. See below for more.

kubectl get all

Actually list everything. May take awhile.

function k_get_all () {
    for i in $(kubectl api-resources --verbs=list --namespaced -o name | \
        grep -v "events.events.k8s.io" | grep -v "events" | sort | uniq); do
            kubectl get --show-kind --ignore-not-found ${i};
    done
}

Show pod logs

kubectl logs pod/<pod>

Use ‘helm upgrade’ to install new version of a chart

This is far simpler than a more complex helm install command with tons of --set options. More infomration here

helm upgrade <release name> <chart name> --reuse-values

Get secret with a dot in its name

The normal access would be something like this:

kubectl get secret argocd-initial-admin-secret -o jsonpath="{.data.password}" | base64 -d

But doing the same thing for a secret with a dot in its name wouldn’t work, thus:

kubectl get secret docker-config -o jsonpath="{.data.\.dockerconfigjson}" | base64 -d

An alternative would be to use go-template:

kubectl get secret docker-config -o 'go-template={{index .data ".dockerconfigjson"}}' | base64 -d