HMPPS Helm Charts

Here you will find a common place for helm charts used by HMPPS projects/services. (Click here to see which services use them.)

The charts are built and published via GitHub Actions and GitHub pages, see https://github.com/helm/chart-releaser

Making changes

Most projects will pin to a specific minor version. Patch releases should therefore be limited to bug fixes and other new functionality that will not affect deployments.

It is important to test out any changes locally on a variety of projects prior to raising a PR.

Worth bearing in mind when making changes - these charts can be used by services running in clusters hosted on CloudPlatform (#ask-cloud-platform) or Digital Studio Ops (#ask-digital-studio-ops), and they may have different #configuration. The parameter dso_enabled was introduced to toggle features for services running in the DSO cluster.

Once a PR has been merged and a release created please edit the latest release with information on what has changed.

Quick start

Add new charts to /charts directory, create PR, once merged to main branch github actions will publish the chart.

Repo URL = https://ministryofjustice.github.io/hmpps-helm-charts

You can add this repo to your local helm config like this:

helm repo add hmpps-helm-charts https://ministryofjustice.github.io/hmpps-helm-charts

Search for published charts:

helm search repo hmpps-helm-charts

Testing changes locally

To locally test how a change to this repository affects a project, instead of referencing the GitHub repo as a dependency in that project such as:

dependencies:
  - name: generic-service
    version: <some-version>
    repository: https://ministryofjustice.github.io/hmpps-helm-charts

you can reference this repository in your local file system as:

dependencies:
  - name: generic-service
    version: <some-version>
    repository: file:///<path-to-hmpps-helm-charts>/charts/generic-service

Then run:

helm dependency update <directory-containing-project-chart>

Then can run a dry-run upgrade to see the effect:

helm upgrade \
  --dry-run \
  --namespace my-namespace \
  --values=<values-file> \
  <release-name> \
  <directory-containing-project-chart>

for example:

helm upgrade \
  --dry-run \
  --namespace hmpps-education-and-work-plan-dev \
  --values ./helm_deploy/values-dev.yaml \
  hmpps-education-and-work-plan-api \
  ./helm_deploy/hmpps-education-and-work-plan-api

You can also compare the template yaml by running the following both before and after your changes, saving the output to files:

helm template \
  --namespace my-namespace \
  --values=<values-file> \
  <release-name> \
  <directory-containing-project-chart>

Unit Testing Prometheus Alerts

To run the unit tests you will need yq, envsubst, and promtool installed, these can be installed on a Mac via homebrew:

brew install yq prometheus gettext

Then simply run the following to run the unit tests:

make test

More information on how to write a Prometheus rule unit test can be found on the Prometheus docs, see https://www.prometheus.io/docs/prometheus/latest/configuration/unit_testing_rules/