feat: add argo-cd app preview template

README.md

@@ -2,6 +2,16 @@
 
 Utility tools & scripts.
 
+## Devops
+
+### ArgoCD app previews
+
+Templates to configure preview environments with ArgoCD by using the Pull Request Generator. The Pull Request generator uses the API of an SCMaaS provider (GitHub, GitLab, Gitea, Bitbucket, ...) to automatically discover open pull requests within a repository, this fits well with the style of building a test environment when you create a pull request.
+
+- [github-appset.yaml](./devops/argo-cd-app-preview/github-appset.yaml)
+
+> For further information, see [ArgoCD documentation](https://argo-cd.readthedocs.io/en/stable/operator-manual/applicationset/Generators-Pull-Request).
+
 ## Docker
 
 ### Utils images

devops/argo-cd-app-preview/github-appset.yaml

@@ -0,0 +1,66 @@
+# ApplicationSet template used for preview app in CI/CD
+#
+# You need to replace all values following the `<variable_name>` pattern
+# and adapt some values from the current template.
+# see. https://argo-cd.readthedocs.io/en/stable/operator-manual/applicationset/Generators-Pull-Request/#github
+---
+apiVersion: argoproj.io/v1alpha1
+kind: ApplicationSet
+metadata:
+  name: <github_repository>-preview
+  namespace: <argocd_namespace>
+spec:
+  generators:
+  - pullRequest:
+      github:
+        owner: <github_username>
+        repo: <github_repository>
+        labels:
+        - preview
+        - built
+        appSecretName: <repo_secret> # Secret containing Github App infos (see. https://argo-cd.readthedocs.io/en/stable/operator-manual/declarative-setup/#github-app-repositories)
+  template:
+    metadata:
+      name: <github_repository>-preview-pr-{{number}}
+    spec:
+      destination:
+        namespace: <github_repository>-pr-{{number}}
+        server: https://kubernetes.default.svc
+      project: <argocd_project>
+      source:
+        repoURL: https://github.com/<github_username>/<github_repository>.git
+        path: ./helm
+        targetRevision: main # 1.*.*
+        helm:
+          values: |
+            api:
+              image:
+                tag: pr-{{number}}
+              ingress:
+                annotations:
+                  cert-manager.io/cluster-issuer: <cluster_issuer>
+                hosts:
+                - host: api.pr-{{number}}.domain.com
+                tls:
+                - secretName: api.pr-{{number}}.domain.com-tls
+                  hosts:
+                  - api.pr-{{number}}.domain.com
+            docs:
+              image:
+                tag: pr-{{number}}
+              ingress:
+                annotations:
+                  cert-manager.io/cluster-issuer: <cluster_issuer>
+                hosts:
+                - host: docs.pr-{{number}}.domain.com
+                tls:
+                - secretName: docs.pr-{{number}}.domain.com-tls
+                  hosts:
+                  - docs.pr-{{number}}.domain.com
+            ...
+      syncPolicy:
+        syncOptions:
+        - CreateNamespace=true
+        - ApplyOutOfSyncOnly=true
+        automated:
+          selfHeal: true