download manifests from specific prometheus version

ansible/roles/apps/tasks/helmfiles.yml

@@ -30,7 +30,8 @@
   tags:
     - helmfile
     - monitoring
-  command: '/snap/bin/kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/master/example/prometheus-operator-crd/{{ item }}'
+  # NOTE: Change the commit hash in the URL when upgrading Prometheus
+  command: '/snap/bin/kubectl apply -f https://raw.githubusercontent.com/coreos/prometheus-operator/3c7f982b4f03976d4f354e2dee0331c2cf877194/example/prometheus-operator-crd/{{ item }}'
   loop:
     - alertmanager.crd.yaml
     - prometheus.crd.yaml

helmfiles/helmfile.d/15-monitoring.yaml

@@ -7,7 +7,9 @@ releases:
   - name: "oas-{{ .Environment.Values.releaseName }}-prometheus"
     namespace: "oas"
     chart: "stable/prometheus-operator"
-    version: 6.21.0
+    # NOTE: If you change this version, also change the commit hash in
+    # ansible/roles/apps/tasks/helmfiles.yml:34
+    version: 5.15.0
     values:
     - "../values/prometheus.yaml.gotmpl"
     - "/etc/OpenAppStack/values/apps/prometheus.yaml.gotmpl"