Kubectl patch: Difference between revisions
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===Update the Image on a Deployment=== | ===Update the Image on a Deployment=== | ||
Updates the <code>image</code> field of the first container in the containers array. | |||
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kubectl patch deployment my-deployment --type=json --patch='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value": "docker.io/ovidiufeodorov/httpd:test_2"}]' | kubectl patch deployment my-deployment --type=json --patch='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value": "docker.io/ovidiufeodorov/httpd:test_2"}]' | ||
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Revision as of 19:32, 29 July 2021
External
- https://kubernetes.io/docs/reference/generated/kubectl/kubectl-commands#patch
- https://kubernetes.io/docs/tasks/manage-kubernetes-objects/update-api-object-kubectl-patch/
Internal
Overview
kubectl patch supports the following modes: strategic merge patch ("strategic"), JSON merge patch ("merge") and JSON patch ("json").
Caveats
⚠️There are situations when the patch apparently succeeds, the kubectl patch command exits with 0 and if the resource is queried immediately, the patch seems to be applied, but when the resource is queried a while later (15 secs), it becomes apparent that the "patch" did not take. This happened while trying to unbind a PV from the PVC while the PVC is still active.
Usage Examples
JSON Patch Usage Examples
Delete a Field with a JSON Patch
Unbind a PVC from a PV by deleting the PV's claimRef:
kubectl patch pv my-pv --type=json --patch='[{"op": "remove", "path": "/spec/claimRef"}]'
Update the Image on a Deployment
Updates the image field of the first container in the containers array.
kubectl patch deployment my-deployment --type=json --patch='[{"op": "replace", "path": "/spec/template/spec/containers/0/image", "value": "docker.io/ovidiufeodorov/httpd:test_2"}]'