chore(argo-cd)!: Remove apps, appprojs and deprecated features (#1417)

* feat(argo-cd): move server additionalApplications/additionalProjects to argocd-apps chart
Signed-off-by: yu-croco <yuki.kita22@gmail.com>

* Remove deprecated features
Signed-off-by: Petr Drastil <petr.drastil@gmail.com>

* chore(argo-cd): improve release note
Signed-off-by: yu-croco <yu.croco@gmail.com>

Co-authored-by: yu-croco <yuki.kita22@gmail.com>
Co-authored-by: Petr Drastil <petr.drastil@gmail.com>

charts/argo-cd/README.md.gotmpl

@@ -98,6 +98,92 @@ kubectl apply -k "https://github.com/argoproj/argo-cd/manifests/crds?ref=<appVer
 kubectl apply -k "https://github.com/argoproj/argo-cd/manifests/crds?ref=v2.4.9"
 ```
 
+### 5.0.0
+
+This version **removes support for**:
+
+- deprecated repository credentials (parameter `configs.repositoryCredentials`)
+- option to run application controller as a Deployment
+- the parameters `server.additionalApplications` and `server.additionalProjects`
+
+Please carefully read the following section if you are using these parameters!
+
+In order to upgrade Applications and Projects safely against CRDs' upgrade, `server.additionalApplications` and `server.additionalProjects` are moved to [argocd-apps](../argocd-apps).
+
+If you are using `server.additionalApplications` or `server.additionalProjects`, you can adopt to [argocd-apps](../argocd-apps) as below:
+
+1. Add [helm.sh/resource-policy annotation](https://helm.sh/docs/howto/charts_tips_and_tricks/#tell-helm-not-to-uninstall-a-resource) to avoid resources being removed by upgrading Helm chart
+
+You can keep your existing CRDs by adding `"helm.sh/resource-policy": keep` on `additionalAnnotations`, under `server.additionalApplications` and `server.additionalProjects` blocks, and running `helm upgrade`.
+
+e.g:
+
+```yaml
+server:
+  additionalApplications:
+    - name: guestbook
+      namespace: argocd
+      additionalLabels: {}
+      additionalAnnotations:
+        "helm.sh/resource-policy": keep # <-- add this
+      finalizers:
+      - resources-finalizer.argocd.argoproj.io
+      project: guestbook
+      source:
+        repoURL: https://github.com/argoproj/argocd-example-apps.git
+        targetRevision: HEAD
+        path: guestbook
+        directory:
+          recurse: true
+      destination:
+        server: https://kubernetes.default.svc
+        namespace: guestbook
+      syncPolicy:
+        automated:
+          prune: false
+          selfHeal: false
+      ignoreDifferences:
+      - group: apps
+        kind: Deployment
+        jsonPointers:
+        - /spec/replicas
+      info:
+      - name: url
+        value: https://argoproj.github.io/
+```
+
+You can also keep your existing CRDs by running the following scripts.
+
+```bash
+# keep Applications
+for app in "guestbook"; do
+  kubectl annotate --overwrite application $app helm.sh/resource-policy=keep
+done
+
+# keep Projects
+for project in "guestbook"; do
+  kubectl annotate --overwrite appproject $project helm.sh/resource-policy=keep
+done
+```
+
+2. Upgrade argo-cd Helm chart to v5.0.0
+
+3. Remove keep [helm.sh/resource-policy annotation](https://helm.sh/docs/howto/charts_tips_and_tricks/#tell-helm-not-to-uninstall-a-resource)
+
+```bash
+# delete annotations from Applications
+for app in "guestbook"; do
+  kubectl annotate --overwrite application $app helm.sh/resource-policy-
+done
+
+# delete annotations from Projects
+for project in "guestbook"; do
+  kubectl annotate --overwrite appproject $project helm.sh/resource-policy-
+done
+```
+
+4. Adopt existing resources to [argocd-apps](../argocd-apps)
+
 ### 4.9.0
 
 This version starts to use upstream image with applicationset binary. Start command was changed from `applicationset-controller` to `argocd-applicationset-controller`