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Kubernetes Apply step

How to deploy independent workloads.

This topic describes settings for the Kubernetes Apply step.

The Apply step is used to deploy workloads outside of the primary and sidecar workloads of the deployment.

For example, you might want to deploy an additional resource only after Harness has verified the deployment of the main resources in the Manifests section.

For the topic on using the step, go to Deploy Manifests Separately using Apply Step.

What workloads can I deploy?

Go to What Can I Deploy in Kubernetes? for more information.

Rolling vs Apply

The following table lists the differences between the Rolling Deployment step (default in a Rolling strategy) and the Apply step (which may be used with any strategy).

Jobs

Rollback

Rolling Deployment step

No

Yes

Apply step

Yes

No

Name

The name for the Apply step.

The step Id is automatically generated from the name and used to reference the step using its Fully Qualified Name (FQN), like <+execution.steps.[step Id].name>.

For example, if the step Id is Apply, the FQN for the step settings are:

  • <+execution.steps.Apply.name>

  • <+execution.steps.Apply.spec.filePaths>

  • <+execution.steps.Apply.spec.skipDryRun>

  • <+execution.steps.Apply.spec.skipSteadyStateCheck>

  • <+execution.steps.Apply.timeout>

Apply manifests from a remote source

Demo Video

Harness provides two options for applying Kubernetes manifests:

  • Service Option: When you configure from the service, you can provide a file path within the manifest source repository configured in the service definition.

  • Remote Option: When you configure the remote option, you can provide a Harness Git connector, a repo location, and a file path to apply any kind of Kubernetes manifest. Harness allows you to provide a values.yaml as well for templating in the configuration.

GITHUB FILE SIZE LIMITATION

When using a GitHub connector to fetch manifest files, the GitHub Contents API has a 1 MB file size limit. If your manifest file exceeds 1 MB, the Apply step will fail.

Workaround: Use the platform-agnostic Git connector instead of the GitHub connector. The Git connector uses git clone, which does not have the same file size limitation. Go to Use the platform-agnostic Git connector to connect to your code repository without the file size constraint.

Alternatively, split your large manifest file into multiple smaller files, each under 1 MB.

KUBERNETES RESOURCE SIZE LIMITS

Even when using the Git connector workaround, be aware that Kubernetes itself enforces size limits on certain resources:

  • ConfigMaps: Cannot exceed 1 MB in total size

  • Custom Resource Definitions (CRDs): Default etcd limit of 1.5 MB

Go to the Kubernetes documentation on ConfigMaps to understand ConfigMap size constraints, and go to the etcd documentation to understand etcd object size limits.

When Remote Manifest is selected, you will see this in the logs:

File Path Configuration for Service Option

Enter the path to a manifest file.

File Path has the following requirements:

  • The path to the manifest for the Apply step must be subordinate to the path for the manifest in the Manifests section of the Service Definition. The manifest cannot be in the same folder as Manifests.

  • The path must include the folder name and the file name.

In the following example, the path used in the Manifests section of the Service Definition is default-k8s-manifests/Manifests/Files/templates/. The Apply step uses a Job manifest in the subfolder jobs/job.yaml.

You can enter multiple file paths in File Path. Simply click Add file

Timeout

How long Harness should run this step before failing it. Enter a minimum of 10m to account for network activity in your target environment.

Skip dry run

By default, Harness uses the --dry-run flag on the kubectl apply command during the Initialize step of this command, which prints the object that would be sent to the cluster without really sending it.

If the Skip Dry Run option is selected, Harness will not use the --dry-run flag.

Skip steady state check

By default, Harness checks to see if a deployed workload has reached steady state.

If you select this option, Harness will not check that the workload has reached steady state.

Skip K8s manifest(s) rendering

By default, Harness uses Go templating and a values.yaml for templating manifest files.

In some cases, you might not want to use Go templating because your manifests use some other formatting.

Use the Skip K8s Manifest(s) Rendering option if you want Harness to skip rendering your manifest files using Go templating.

For details, go to Deploy Manifests Separately using Apply Step.

Advanced Settings

See the following:

See also

FAQ

Where does the Harness Kubernetes Apply step run by default?

In a Kubernetes or Native Helm deployment type, the Apply step runs in the target cluster namespace specified in the Harness pipeline stage Infrastructure under Environment.

How do I configure the Apply step to run in a different namespace then the one defined in the infrastructure definition?

Any namespace in the manifest you are deploying takes precedence over the namespace specified in the Harness stage Infrastructure.

You can use a values.yaml file to specify the namespace and reference it in the manifest.

In an Apply step, you can override this values.yaml and specify a different namespace for that particular Apply step.

Can the Apply Step render empty manifest files?

No, the Kubernetes apply step cannot render empty files. This results in a step failure. The manifest needs to have complete and defined resources to apply.

PreviousWhat can I deploy in Kubernetes?
NextKubernetes Rollout Deploy step

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