Getting started
See Helm’s documentation to get started with Helm.
See the GOV.UK Kubernetes cluster
docs
for an introduction to the cluster or ask #govuk-platform-engineering in
Slack.
Versioned vs unversioned charts
Most of the charts in this repository are designed to be deployed via Argo
CD rather than by helm install.
For these charts, we don’t use Chart.Version or Helm’s packaging system.
A few charts are still installed via helm install (via
Terraform).
Those charts are automatically packaged and
pushed
to our Helm repository when a change to Chart.Version is merged.
Local development
Prerequisites
-
Install Helm and yq
brew install helm yq
-
Clone the repository
git clone git@github.com:alphagov/govuk-helm-charts.git
-
Configure git hooks
cd govuk-helm-charts &&
git config core.hooksPath git-hooks
Installing an application chart without Argo CD
Inspect the template output of your application chart:
cd charts/app-config
ENVIRONMENT=integration
APP=content-publisher
helm template $USER-${APP?} ../generic-govuk-app --values <(
helm template . --values values-${ENVIRONMENT}.yaml |
yq e '.|select(.metadata.name=="'$APP'").spec.source.helm.values'
) --set sentry.enabled=false --set rails.createKeyBaseSecret=false
To deploy it, run helm install $USER-... instead of helm template $USER....
You should see your deployed pod(s) in the list at kubernetes get pods, and
be able to interact with it as normal.
Use helm uninstall $USER-${APP?} to uninstall your chart when you’ve finished.
Chart repository
Some of the charts in this git repository are published via GitHub Actions to a
chart repository hosted on GitHub Pages.
To add the chart repo to Helm:
helm repo add govuk-helm-charts https://alphagov.github.io/govuk-helm-charts/
You can then run helm search repo <alias> to see the charts.
helm repo update retrieves the latest versions of the packages.
Schemas
We have several Custom Resource Definitions (CRDs) installed in our Kubernetes clusters, and referenced by the Helm charts
in this repository.
We use kubeconform to validate our Kubernetes manifests against schemas for
those resources. This helps us ensure that our Helm charts are correct.
kubeconform runs in a GitHub Action as a pre-merge check and can also be run
locally.
You can run the validation tests locally by installing kubeconform and running
mkdir helm-dist
for c in charts/*; do
helm template "$(basename "$c")" "$c" --output-dir helm-dist
done
kubeconform -schema-location default \
-schema-location "https://raw.githubusercontent.com/datreeio/CRDs-catalog/main/{{.Group}}/{{.ResourceKind}}_{{.ResourceAPIVersion}}.json" \
-summary helm-dist
Team
GOV.UK Platform Engineering team looks after this repo. If you’re inside GDS, you can find us in #govuk-platform-engineering or view our kanban board.
Licence
MIT License