Write the values.yaml file

The values.yaml file contains the customizable settings for your application. Those settings can be overriden for each environment in values-environmet.yaml.

As a general rule, only use values.yaml settings for things that may vary between Phalanx environments. If something is the same in every Phalanx environment, it can be hard-coded into the Kubernetes resource templates.

If your application uses workload identity (see Tying service accounts to workload identity), remember to add a setting to configure the Google service account to use.

Injected values

Some values will always be injected by Argo CD into your application automatically as globals, and therefore do not need to be set for each environment. That list is documented in Values injected by Argo CD.

All the injected values that your chart uses should be mentioned for documentation purposes at the bottom of your values.yaml file with empty defaults. This is done automatically for you by the chart starters.

It is possible to inject other values from the environment configuration. For more details, see Values injected by Argo CD.

Documentation

Phalanx uses helm-docs to automate generating documentation for the values.yaml settings.

For this to work correctly, each setting must be immediately preceded by a comment that starts with # -- and is followed by documentation for that setting in Markdown. This documentation may be wrapped to multiple lines.

Add a blank line between settings, before the helm-docs comment for the next setting.

The default value is included in the documentation. The documentation of the default value can be overridden with a comment starting with # @default --. This can be helpful when the default value in values.yaml is not useful (if, for instance, it’s a placeholder). For example:

# -- Tag of Gafaelfawr image to use
# @default -- The appVersion of the chart
tag: ""

For large default values or default values containing a lot of structure, the default behavior of helm-docs is to reproduce the entire JSON-encoded default in the generated documentation. This is often not useful and can break the HTML formatting of the resulting table. Therefore, for settings with long or complex values, use the following convention in a comment immediately before the setting:

# -- Description of the field.
# @default -- See the `values.yaml` file.
setting:
  - Some long complex value

Referring to Docker images

To allow automated dependency updates to work, ensure that any Docker image deployed by your Helm chart uses values.yaml settings for the repository and current tag. These fields must be named repository and tag, respectively, and are conventionally nested under a key named image along with any other image properties that may need to be customized (such as pullPolicy).

Using this format will allow Mend Renovate to detect newer versions and create PRs to update Phalanx.

The main deployment (or stateful set, or cron job, etc.) for a Helm chart should use the appVersion in Chart.yaml as the default value for the image tag. This is done in the Kubernetes resource template. For example:

image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .ChartAppVersion }}"

Next steps