Django Helm Chart

A generic Django (plus Celery) Helm chart.

Preparing your Django app

This chart supports a web plus optional celery and beat deployments. Be prepared to extend it as necessary.

Django settings will be managed by environment variables. django-environ works well for this and can parse the DATABASE_URL connection string. This chart expects SECRET_KEY and DATABASE_URL variables.

Kubernetes works best when it is able to determine application health. Your Django app should have a /_health/ view such as

def health(request):
    return HttpResponse("ok", content_type="text/plain")

urlpatterns = [
    path("_health/", health),
...

Set the value web.livenessProbe.path and web.readinessProbe.path to change the URL.

Run commands

This helm chart will set a "role" environment variable to web, worker, or beat. Your Docker image could read this variable and run the correct command.

Alternatively, set the service.args. For example:

web:
  args:
    - run_it

Remember that Kubernetes "args" are Docker's CMD (or command). Pretty confusing!

Usage

1. Add our Helm chart repo helm repo add django https://burke-software.gitlab.io/django-helm-chart/
2. Review our values.yaml. At a minimum you'll need to set env.secret.SECRET_KEY and env.secret.DATABASE_URL.
3. Install the chart helm install your-app django/django -f your-values.yml

Tips

• Do you really need kubernetes? It's very complex.
• Use helm diff. One typo will wipe your app without warning otherwise.
• While supported, I don't suggest running stateful services like PostgreSQL in kubernetes. Upgrades will likely involve downtime or extensive and arcane knowledge.
• It's fine to use this chart as a reference for your own chart instead of directly using it.
• I don't publish versions or changelogs at this time. You should probably fork this repo.

Managing environment variables and secrets

I suggest either

• Keep them in a values.yml file in a private repo
• Make use of --reuse-values and --set
• Keep them in a non helm chart managed service

Deploying in CI

I use lwolf/helm-kubectl-docker with Gitlab CI. Example.

Support development

Maintaining this chart takes time. Considering supporting it by

• Donating on liberapay
• Check out GlitchTip error tracking, which is where this project started

Commercial support is available - email info@burkesoftware.com

Contributing

Contributions are welcome. Report bugs on GitLab issues. Please only open feature requests that you'd like to implement yourself or pay for.