Add validate argument to helm_template

[pauvos]

SUMMARY

Support helm template --validate:

--validate

validate your manifests against the Kubernetes cluster you are currently pointing at. This is the same validation performed on an install

It's sometimes necessary to render templates against the kubernetes API because helm charts increasingly start to use conditions:

{{- if and (.Capabilities.APIVersions.Has "networking.k8s.io/v1") (semverCompare ">= v1.19.0-0" .Capabilities.KubeVersion.Version) -}}
  {{- $apiVersion = "networking.k8s.io/v1" -}}
{{- else if .Capabilities.APIVersions.Has "networking.k8s.io/v1beta1" -}}
  {{- $apiVersion = "networking.k8s.io/v1beta1" -}}
{{- else -}}
  {{- $apiVersion = "extensions/v1beta1" -}}
{{- end }}
apiVersion: {{ $apiVersion }}
kind: Ingress

Without checking the capabilities of the cluster the above template will render a deprecated extensions/v1beta1 Ingress resource.

ISSUE TYPE

• Feature Pull Request

COMPONENT NAME

kubernetes.core.helm_template

ADDITIONAL INFORMATION

[pauvos]

I would like to add a unittest but I couldn't figure out how to run them.

Does this make sense?

# tests/unit/modules/test_helm_template.py

def test_template_with_validate():
    my_chart_ref = "testref"
    helm_cmd = "helm"
    parser = argparse.ArgumentParser()
    # to "simulate" helm template options, include two optional parameters NAME and CHART.
    # if parsed string contains only one parameter, the value will be passed
    # to CHART and NAME will be set to default value "release-name" as in helm template
    parser.add_argument("cmd")
    parser.add_argument("template")
    parser.add_argument("NAME", nargs="?", default="release-name")
    parser.add_argument("CHART", nargs="+")
    parser.add_argument("--validate", dest="validate", action="store_true")
    parser.set_defaults(validate=False)

    mytemplate = template(cmd=helm_cmd, chart_ref=my_chart_ref, validate=True)

    args, unknown = parser.parse_known_args(mytemplate.split())

    assert args.validate is True

[softwarefactory-project-zuul]

Build failed.
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[abikouo]

@pauvos thanks for your pull request,
could you please add a changelog? here is an example https://github.com/ansible-collections/kubernetes.core/pull/575/files#diff-6d789f5197c05bc24880f186dfc451b420fc61f8666d969d2c7309473aa1e3f1

[pauvos]

@abikouo , yes sure thing!

I have 2 other pull requests:

• fix post_renderer arguments breaking the helm deploy_command #586
• use post_renderer when checking 'changed' status for a helm release #588

Should i merge everything in one pull requests or create individual changelog fragments?

[softwarefactory-project-zuul]

Build failed.
https://ansible.softwarefactory-project.io/zuul/buildset/b0a6cf3c5b284f8698f482c4133cdf1c

✔️ build-ansible-collection SUCCESS in 6m 47s
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Skipped 5 jobs

[gravesm]

Thanks for the PR, and sorry for taking so long to get back to this. Since this is going to connect to a cluster, you'll need to add some connection parameters to the module. This should be pretty easy, though, and you can look at how the helm module does it. I think it should be sufficient to just extend the doc string as it's done in

kubernetes.core/plugins/modules/helm.py

Lines 221 to 222 in 8640c16

	extends_documentation_fragment:
	- kubernetes.core.helm_common_options

and then add those args to the arg spec for the module, similar to how it's done in

kubernetes.core/plugins/modules/helm.py

Line 695 in deb4859

arg_spec = copy.deepcopy(HELM_AUTH_ARG_SPEC)

.

Since this is adding functionality to connect to a cluster, it would be a good idea to add an integration test or two for this. You can add those in

kubernetes.core/tests/integration/targets/helm/tasks/tests_chart.yml

Line 345 in 8640c16

- name: Render templates

and just use that as a guide.

Your suggestion of the unit test seems reasonable. If you want to run unit tests locally you can do so with ansible-test units --docker.

[willthames]

There is an alternative way to achieve the desired results here which is to add an api versions parameter to the helm_template module (this is often useful when there isn't a kubernetes cluster to connect to e.g. during CI - this is how we generate all of our templates)

e.g. for the alb-controller we pass -a cert-manager.io/v1 -a admissionregistration.k8s.io/v1