Debug Kustomize: troubleshooting commands

Kustomize 5.8 10 commands

10 commands in 2 groups: Debug Build, Inspect & Diff. Click or tap any command to copy it. Official documentation: kubectl.docs.kubernetes.io.

Open in the interactive cheat sheet search, stars and every other section

Debug Build

Diagnose render failures and validate the output of an overlay before applying it to the cluster.

kubectl apply -k <dir> --dry-run=client

Preview the apply without persisting anything (client-side, still needs cluster access)

kubectl apply -k <dir> --dry-run=server

Server-side dry-run for admission webhook checks

kustomize build <dir>

Render overlay to see full output or error message

kustomize build --load-restrictor=LoadRestrictionsNone <dir>

Allow files outside the kustomization root (common path error)

kustomize build --enable-alpha-plugins --enable-exec <dir>

Enable plugins and KRM functions, including exec functions (trusted configs only)

Compare rendered output against the live cluster state and verify specific fields like images and namespaces.

kustomize build <dir> | grep 'image:'

Verify image substitutions in rendered output

kustomize build <dir> | grep 'namespace:'

Check namespace assignments in rendered output

kustomize build <dir> | grep -A5 'kind: <Kind>'

Find a specific resource kind in rendered output

kubectl diff -k <dir>

Diff overlay against live cluster state

kubectl get -k <dir>

List all resources the overlay manages