kubectl Usage Conventions

Recommended usage conventions for kubectl.

Using kubectl in Reusable Scripts

For a stable output in a script:

• Request one of the machine-oriented output forms, such as -o name, -o json, -o yaml, -o go-template, or -o jsonpath.
• Fully-qualify the version. For example, jobs.v1.batch/myjob. This will ensure that kubectl does not use its default version that can change over time.
• Don't rely on context, preferences, or other implicit states.

Best Practices

kubectl run

For kubectl run to satisfy infrastructure as code:

• Tag the image with a version-specific tag and don't move that tag to a new version. For example, use :v1234, v1.2.3, r03062016-1-4, rather than :latest (For more information, see Best Practices for Configuration).
• Check in the script for an image that is heavily parameterized.
• Switch to configuration files checked into source control for features that are needed, but not expressible via kubectl run flags.

You can use the --dry-run=client flag to preview the object that would be sent to your cluster, without really submitting it.

kubectl apply

• You can use kubectl apply to create or update resources. For more information about using kubectl apply to update resources, see Kubectl Book.