debian-mirror-gitlab/doc/user/clusters/management_project_template.md

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Cluster Management Project Template (FREE)

• Introduced in GitLab 12.10 with Helmfile support via Helm v2.
• Improved in GitLab 14.0 with Helmfile support via Helm v3 instead, and a much more flexible usage of Helmfile. This introduces breaking changes that are detailed below.

This GitLab built-in project template provides a quicker start for users interested in managing cluster applications via Helm v3 charts. More specifically, taking advantage of the Helmfile utility client. The template consists of some pre-configured apps that should help you get started quickly using various GitLab features. Still, you have all the flexibility to remove the ones you do not need, or even add new ones that are not built-in.

How to use this template

1. Create a new project, choosing "GitLab Cluster Management" from the list of built-in project templates.
2. Make this project a cluster management project.
3. If you used the GitLab Managed Apps, refer to Migrating from GitLab Managed Apps.

Components

In the repository of the newly-created project, you will find:

• A predefined .gitlab-ci.yml file, with a CI pipeline already configured.
• A main helmfile.yaml to toggle which applications you would like to manage.
• An applications directory with a helmfile.yaml configured for each application GitLab provides.

The .gitlab-ci.yml file

The base image used in your pipeline is built by the cluster-applications project. This image consists of a set of Bash utility scripts to support Helm v3 releases:

• gl-fail-if-helm2-releases-exist {namespace}: It tries to detect whether you have apps deployed through Helm v2 releases for a given namespace. If so, it will fail the pipeline and ask you to manually migrate your Helm v2 releases to Helm v3.
• gl-ensure-namespace {namespace}: It creates the given namespace if it does not exist and adds the necessary label for the Cilium app network policies to work.
• gl-adopt-resource-with-helm-v3 {arguments}: Used only internally in the cert-manager's Helmfile to facilitate the GitLab Managed Apps adoption.
• gl-adopt-crds-with-helm-v3 {arguments}: Used only internally in the cert-manager's Helmfile to facilitate the GitLab Managed Apps adoption.
• gl-helmfile {arguments}: A thin wrapper that triggers the Helmfile command.

The main helmfile.yml file

This file has a list of paths to other Helmfiles for each app. They're all commented out by default, so you must uncomment the paths for the apps that you would like to manage.

By default, each helmfile.yaml in these sub-paths will have the attribute installed: true, which signifies that everytime the pipeline runs, Helmfile will try to either install or update your apps according to the current state of your cluster and Helm releases. If you change this attribute to installed: false, Helmfile will try to uninstall this app from your cluster. Read more about how Helmfile works.

Furthermore, each app has an applications/{app}/values.yaml file. This is the place where you can define some default values for your app's Helm chart. Some apps will already have defaults pre-defined by GitLab.

Built-in applications

The built-in applications are intended to provide an easy way to get started with various Kubernetes oriented GitLab features.

The built-in supported applications are:

• Apparmor
• Cert-manager
• Cilium
• Elastic Stack
• Falco
• Fluentd
• GitLab Runner
• Ingress
• Prometheus
• Sentry
• Vault

Migrating from GitLab Managed Apps

If you had GitLab Managed Apps, either One-Click or CI/CD install, read the docs on how to migrate from GitLab Managed Apps to project template