Welcome to plural-artifacts

This is a central repository for packaging all the applications we're managing within Plural. In general, there's a common structure to the layout of all these apps:

<app-name>/
- helm // helm charts for the app
- terraform // terraform modules for the app
- plural // plural metadata
repository.yaml // repository specification

There's also a Makefile with some useful utilities for managing these files.

Adding a new application

To add a new application, you'll want to run plural create and answer the brief questionnaire. This will generate the above directory structure with stub implementations for most of the basic resources. Generally we try to extend the existing upstream Helm packaging, so you'll ideally want to find an already working Helm chart, research its configuration and modify it appropriately. General rules of thumb are:

• Replace all built-in stateful services
  • Many charts will bake in a Bitnami Postgres Helm chart. You'll want to replace this with our Zalando Postgres operator setup which will have backup/restore and high availability set up already
  • Some apps use Elasticsearch, Kafka, MongoDB, etc. We have operator setups in the catalog for these applications that you can use here
  • Frequently, Redis can be left as-is if it's purely used for memory caching. We leave this to the judgement of the user
• Try to build out as many config overlays and runbooks as possible. You can look to Airflow and Airbyte for inspiration for how to do this.
• If the app supports OIDC, ensure this is configurable.

You can learn more about all the custom resources that can be used when building out the packaging for an application here as well.

Upgrading an application

The upgrade process usually involves two main steps:

• figure out how to update the app's Helm chart
• test it using plural link

To test, you'll need to already have the app installed in some cluster. The `plural link command works similarly to yarn or npm link if you're familiar with either. Basically, within the installation repo for that app, run:

plural link {helm|terraform} <app-name> --path ../plural-artifacts/<app-name>/{helm|terraform}/<package-name> --name <package-name>

Then you can run:

plural build --only <app-name> --force
plural deploy

This deploys the app with the local link you established. The --force flag will prevent any deduping w/in the Plural CLI from triggering.

Helpful utilities

If you're frequently updating Helm dependencies, it can be complicated to sync them locally. To make this easier, you can just run:

make helm-dependencies-<app>

If you have publish access to this repo, you can publish your changes directly with the following command:

make upload-<app>

Only do this for apps that have not yet been publicly released