feat: support PG4K namespaces installations

Signed-off-by: Leonardo Cecchi <[email protected]>

README.md

@@ -42,6 +42,18 @@ edb-pg4k-edb-postgres-for-kubernetes   1/1     1            1           11s
 Once it is ready, you can verify that you can deploy the sample cluster
 suggested by the helm chart.
 
+It is possible to limit the operator's capabilities to solely the namespace in
+which it has been set up. By implementing this restriction, the cluster-level
+permissions required by the operator will be substantially minimized:
+
+```console
+helm upgrade --install edb-pg4k \
+  --namespace postgresql-operator-system \
+  --create-namespace \
+  --set config.clusterWide=false \
+  edb/edb-postgres-for-kubernetes
+```
+
 ### Deploying EDB Postgres for Kubernetes (PG4K) operator from EDB's private registry
 
 By default, PG4K will be deployed using [images publicly hosted on Quay.io](https://quay.io/repository/enterprisedb/cloud-native-postgresql),

charts/edb-postgres-for-kubernetes/templates/NOTES.txt

@@ -8,11 +8,14 @@ apiVersion: postgresql.k8s.enterprisedb.io/v1
 kind: Cluster
 metadata:
   name: cluster-example
+  {{if not .Values.config.clusterWide  -}}
+  namespace: {{ .Release.Namespace }}
+  {{- end }}
 spec:
   instances: 3
   storage:
     size: 1Gi
 EOF
 
-kubectl get cluster
+kubectl get -A cluster
 

charts/edb-postgres-for-kubernetes/templates/config.yaml

@@ -25,7 +25,13 @@ metadata:
     {{- toYaml . | nindent 4 }}
   {{- end }}
 data:
+  {{- if .Values.config.clusterWide  -}}
   {{- toYaml .Values.config.data | nindent 2 }}
+  {{- else -}}
+  {{- $watchNamespaceMap := dict "WATCH_NAMESPACE" .Release.Namespace -}}
+  {{- $fullConfiguration := merge .Values.config.data $watchNamespaceMap -}}
+  {{- toYaml $fullConfiguration | nindent 2 }}
+  {{- end -}}
 {{- end }}
 {{- else -}}
 apiVersion: v1

charts/edb-postgres-for-kubernetes/templates/deployment.yaml

@@ -64,6 +64,10 @@ spec:
               fieldPath: metadata.namespace
         - name: MONITORING_QUERIES_CONFIGMAP
           value: "{{ .Values.monitoringQueriesConfigMap.name }}"
+        {{ if not .Values.config.clusterWide -}}
+        - name: WATCH_NAMESPACE
+          value: "{{ .Release.Namespace }}"
+        {{- end }}
         image: "{{ .Values.image.repository }}:{{ .Values.image.tag | default .Chart.AppVersion }}"
         imagePullPolicy: {{ .Values.image.pullPolicy }}
         livenessProbe: