Control Plane repository defines the desired state of shared infrastructure components and enables self-service onboarding process for the application developer teams.

This git repository is part of the project GitOps Bridge

Repository contains the following directories:

- bootstrap      # The Applications and ApplicationSets used for Argo CD bootstrapping.
- charts         # Local Helm charts.
- clusters       # Cluster specific configurations, including values for addons.
- environments   # Environment specific configurations, including values for addons.
- global         # The default `values.yaml` for charts used by addons.

The bootstrap folder is used as the source for the initial Application created by Terraform after standing up an instance of Argo CD. It bootstraps the instance with an Application that deploys ApplicationSets for managing cluster addons, and an ApplicationSet for deploying cluster-specific Applications (e.g. from the clusters/<name> folders).

Each cluster can opt into addons deployed into it.

The global/addons, clusters/<name>/addons, and environments/<name>/addons folders are used to provide values.yaml to the addons charts.

For example, the argo-rollouts addon chart used in the dev environment and gke cluster, is supplied the following values files (in order of precidence):

• global/addons/argo-rollouts/values.yaml
• environments/dev/addons/argo-rollouts/values.yaml
• clusters/gke/addons/argo-rollouts/values.yaml

1. Create a folder with the same name as the chart under global/addons, environments/*/addons, and clusters/*/addons.
2. Add an empty values.yaml to each of those folders.
3. Add the chart information in bootstrap/addons-app.yaml under the spec.source.helm.valuesObject.addons list.

   spec:
     source:
       helm:
       valuesObject:
         addons:
         - chartName: argo-rollouts
           chartRepo: https://argoproj.github.io/argo-helm
           chartVersionDefault: 2.32.0

4. In the Terraform configuration, add the cooresponding enable_<chart_name_snakecase> to the annotations of the clusters that should recieve the addon.

Each cluster will need a folder with the same name (as what's defined in Argo CD) under clusters/. The clusters ApplicationSet (deployed by the Argo CD bootstrapping) will create an Application to deploy any Application manifests in the apps folder. A cluster can have any number of arbitrary Applications deployed to it by simply adding them to it's corriesponding folder. Including ones that point to another GitOps repo that contains the application-specific configurations.

For example, to create an Application for the gke-dev cluster, simply add the manifest to the clusters/gke-dev/apps folder. From there the cluster-gke-dev-apps Applicaiton (created by the clusters-apps ApplicaitonSet) will deploy it so that Argo CD will pick it up and start deploying the resources to the cluster.