First commit

README.md

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+This repo, in conjunction with the [App Code repo](https://gitea.scubbo.org/scubbo/auto-update-test-app-code), demonstrates how to use the Auto-Update Drone Plugin to trigger App deployments in a CI/CD pipeline which uses GitOps to define the App Versions in Git.
+
+## Demonstration
+
+While in the App Code repo, at commit `65866e` ([link](https://gitea.scubbo.org/scubbo/auto-update-test-app-code/commit/65866ea3b60906d60c4c7aa22b51333cb906c839)), and having already carried out a "first-pass" sync in my CD application (ArgoCD) to get components deployed:
+
+```
+# Make the deployed pod "call itself" - saves us from the hassle of setting up a Service
+$ kubectl exec -it -n auto-update $(kubectl -n auto-update get pods -o=jsonpath='{.items[*].metadata.name}') -- curl localhost:8000
+Hello world!%
+# OK, good - as expected, the Application initially responds with "Hello world!". Now let's make a change and demonstrate that it's deployed.
+$ git reset --hard cffc43
+HEAD is now at cffc437 Expand project scope
+$ git status
+On branch main
+Your branch is ahead of 'origin/main' by 1 commit.
+
+nothing to commit, working tree clean
+$ git push
+[...]
+To https://gitea.scubbo.org/scubbo/auto-update-test-app-code.git
+   65866ea..cffc437  main -> main
+#
+# Now observe:
+# * the Drone pipeline results in a commit to the infra package...
+# * ...which is visible in Gitea
+# * Once the Argo application is synced, new Kubernetes resources are created to match the new Infrastructure definition
+#
+$ kubectl exec -it -n auto-update $(kubectl -n auto-update get pods -o=jsonpath='{.items[*].metadata.name}') -- curl localhost:8000
+Hello universe!
+```
+
+
+
+## Points to note
+* `helm/templates/_helpers.tpl` contains the `fullImageName` definition, which in turn depends on `imageTag`, which uses [Files access](https://helm.sh/docs/chart_template_guide/accessing_files) to read the contents of `helm/deployed-images/<targetEnv>`
+* The value `targetEnv` must be set in the setup for the specific CD application which will "watch" this repo for updates.

helm/Chart.yaml

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+apiVersion: v2
+name: auto-update-test-infra
+description: A Helm chart for Kubernetes, demonstrating auto-update functionality
+
+type: application
+version: 0.1.0
+appVersion: "1.1.0"

helm/deployed-images/prod

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+9b6b005ca3

helm/templates/_helpers.tpl

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+{{- define "imageTag" }}
+{{- $val := "" }}
+{{- if and (hasKey .Values.image "tag") (.Values.image.tag) }}
+{{- $val = .Values.image.tag }}
+{{- else }}
+{{- $val = (.Files.Get (printf "%s/%s" "deployed-images" (required "You must set targetEnv if image.tag is absent!" .Values.targetEnv))) }}
+{{- end }}
+{{- trim $val }}
+{{- end }}
+
+{{- define "fullImageName" -}}
+{{- printf "%s:%s" .Values.image.repository (include "imageTag" .) }}
+{{- end }}

helm/templates/infra.yaml

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+apiVersion: apps/v1
+kind: Deployment
+metadata:
+  name: auto-update-test-infra
+spec:
+  selector:
+    matchLabels:
+      app: auto-update-test-infra
+  template:
+    metadata:
+      labels:
+        app: auto-update-test-infra
+    spec:
+      containers:
+        - name: auto-update-test-infra
+          image: {{ include "fullImageName" . }}

helm/values.yaml

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+image:
+  repository: gitea.scubbo.org/scubbo/auto-update-test-app-code