Argo-CD example improvements (#2200)

* Sync ArgoCD example with latest components from example.jsonnet

* Extend the ArgoCD example to include ArgoCD related annotations to make everything work on first try

* Run jsonnetfmt

examples/continuous-delivery/argocd/README.md

 ## ArgoCD Example
 
-This is the simplest, working example of an argocd app, the JSON object built is now an array of objects as that is the prefered format for ArgoCD.
+This is the simplest, working example of an argocd app, the JSON object built is now an array of objects as that is the prefered format for ArgoCD. And ArgoCD specific annotations are added to manifests.
 
 Requirements:
 
-**ArgoCD 1.7+**
+- **ArgoCD 1.7+**
 
-Follow the vendor generation steps at the root of this repository and generate a `vendored` folder (referenced in `application.yaml`).
+- Follow the vendor generation steps at the root of this repository and generate a `vendored` folder (referenced in `application.yaml`).
+
+- Make sure that argocd-cm has `application.instanceLabelKey` set to something else than `app.kubernetes.io/instance`, otherwise it will cause problems with prometheus target discovery. (see also [Why Is My App Out Of Sync Even After Syncing?](https://argo-cd.readthedocs.io/en/stable/faq/#why-is-my-app-out-of-sync-even-after-syncing))

examples/continuous-delivery/argocd/kube-prometheus/argocd-basic.jsonnet

-local kp = (import 'kube-prometheus/main.libsonnet') + {
-  values+:: {
-    common+: {
-      namespace: 'monitoring',
+// NB! Make sure that argocd-cm has `application.instanceLabelKey` set to something else than `app.kubernetes.io/instance`,
+//     otherwise it will cause problems with prometheus target discovery.
+//     See also https://argo-cd.readthedocs.io/en/stable/faq/#why-is-my-app-out-of-sync-even-after-syncing
+
+local kp =
+  (import 'kube-prometheus/main.libsonnet') +
+  // Uncomment the following imports to enable its patches
+  // (import 'kube-prometheus/addons/anti-affinity.libsonnet') +
+  // (import 'kube-prometheus/addons/managed-cluster.libsonnet') +
+  // (import 'kube-prometheus/addons/node-ports.libsonnet') +
+  // (import 'kube-prometheus/addons/static-etcd.libsonnet') +
+  // (import 'kube-prometheus/addons/custom-metrics.libsonnet') +
+  // (import 'kube-prometheus/addons/external-metrics.libsonnet') +
+  // (import 'kube-prometheus/addons/pyrra.libsonnet') +
+  {
+    values+:: {
+      common+: {
+        namespace: 'monitoring',
+      },
     },
-  },
-};
-
-[kp.kubePrometheus[name] for name in std.objectFields(kp.kubePrometheus)] +
-[kp.prometheusOperator[name] for name in std.objectFields(kp.prometheusOperator)] +
-[kp.nodeExporter[name] for name in std.objectFields(kp.nodeExporter)] +
-[kp.kubeStateMetrics[name] for name in std.objectFields(kp.kubeStateMetrics)] +
-[kp.prometheus[name] for name in std.objectFields(kp.prometheus)] +
-[kp.prometheusAdapter[name] for name in std.objectFields(kp.prometheusAdapter)]
+  };
+
+// Unlike in kube-prometheus/example.jsonnet where a map of file-names to manifests is returned,
+// for ArgoCD we need to return just a regular list with all the manifests.
+local manifests =
+  [kp.kubePrometheus[name] for name in std.objectFields(kp.kubePrometheus)] +
+  [kp.prometheusOperator[name] for name in std.objectFields(kp.prometheusOperator)] +
+  [kp.alertmanager[name] for name in std.objectFields(kp.alertmanager)] +
+  [kp.blackboxExporter[name] for name in std.objectFields(kp.blackboxExporter)] +
+  [kp.grafana[name] for name in std.objectFields(kp.grafana)] +
+  // [ kp.pyrra[name] for name in std.objectFields(kp.pyrra)] +
+  [kp.kubeStateMetrics[name] for name in std.objectFields(kp.kubeStateMetrics)] +
+  [kp.kubernetesControlPlane[name] for name in std.objectFields(kp.kubernetesControlPlane)] +
+  [kp.nodeExporter[name] for name in std.objectFields(kp.nodeExporter)] +
+  [kp.prometheus[name] for name in std.objectFields(kp.prometheus)] +
+  [kp.prometheusAdapter[name] for name in std.objectFields(kp.prometheusAdapter)];
+
+local argoAnnotations(manifest) =
+  manifest {
+    metadata+: {
+      annotations+: {
+        'argocd.argoproj.io/sync-wave':
+          // Make sure to sync the Namespace & CRDs before anything else (to avoid sync failures)
+          if std.member(['CustomResourceDefinition', 'Namespace'], manifest.kind)
+          then '-5'
+          // And sync all the roles outside of the main & kube-system last (in case some of the namespaces don't exist yet)
+          else if std.objectHas(manifest, 'metadata')
+                  && std.objectHas(manifest.metadata, 'namespace')
+                  && !std.member([kp.values.common.namespace, 'kube-system'], manifest.metadata.namespace)
+          then '10'
+          else '5',
+        'argocd.argoproj.io/sync-options':
+          // Use replace strategy for CRDs, as they're too big fit into the last-applied-configuration annotation that kubectl apply wants to use
+          if manifest.kind == 'CustomResourceDefinition' then 'Replace=true'
+          else '',
+      },
+    },
+  };
+
+// Add argo-cd annotations to all the manifests
+[
+  if std.endsWith(manifest.kind, 'List') && std.objectHas(manifest, 'items')
+  then manifest { items: [argoAnnotations(item) for item in manifest.items] }
+  else argoAnnotations(manifest)
+  for manifest in manifests
+]