Argo CD ApplicationSet CRD

The Argo CD ApplicationSet CRD and controller provides a formal solution to replace the app-of-apps pattern with the ultimate goal of introducing ApplicationSet as a first class supported object in Argo CD Core.

This project will initially be maintained separately from Argo CD, in order to allow quick iteration of the spec and implementation, without tying it to Argo CD releases. No promises of backwards compatibility are made, at least until merging into Argo CD proper.

Proposal:

• https://docs.google.com/document/d/1juWGr20FQaJmuuTIS8mBFmWWDU422M_FQMuhp5c1jt4/edit?usp=sharing

Example Spec:

# This is an example of a typical ApplicationSet which uses the cluster generator.
# An ApplicationSet is comprised with two stanzas:
#  - spec.generator - producer of a list of values supplied as arguments to an app template
#  - spec.template - an application template, which has been parameterized
apiVersion: argoproj.io/v1alpha1
kind: ApplicationSet
metadata:
  name: guestbook
spec:
  generators:
  - clusters: {}
  template:
    metadata:
      name: '{{name}}-guestbook'
    spec:
      source:
        repoURL: https://github.com/infra-team/cluster-deployments.git
        targetRevision: HEAD
        chart: guestbook
      destination:
        server: '{{server}}'
        namespace: guestbook

Additional examples are available in the examples directory.