feat: add balancer database cluster manifest

deploy/manifests/balancer/base/database.yaml

@@ -0,0 +1,10 @@
+apiVersion: postgresql.cnpg.io/v1
+kind: Database
+metadata:
+  name: balancer
+  namespace: cloudnative-pg
+spec:
+  name: balancer
+  owner: balancer
+  cluster:
+    name: shared-cluster

deploy/manifests/balancer/base/kustomization.yaml

@@ -6,3 +6,13 @@ resources:
   - deployment.yaml
   - service.yaml
   - ingress.yaml
+  - database.yaml
+
+patches:
+  - target:
+      kind: Database
+      name: balancer
+    patch: |-
+      - op: replace
+        path: /metadata/namespace
+        value: cloudnative-pg

deploy/manifests/balancer/overlays/sandbox/configmap.yaml

@@ -0,0 +1,10 @@
+apiVersion: v1
+kind: ConfigMap
+metadata:
+  name: balancer-db-config
+data:
+  SQL_HOST: shared-cluster-rw.cloudnative-pg.svc.cluster.local
+  SQL_PORT: "5432"
+  SQL_DATABASE: balancer
+  SQL_USER: balancer
+  SQL_ENGINE: django.db.backends.postgresql

deploy/manifests/balancer/overlays/sandbox/kustomization.yaml

@@ -0,0 +1,27 @@
+apiVersion: kustomize.config.k8s.io/v1beta1
+kind: Kustomization
+
+namespace: balancer
+
+resources:
+  - ../../base
+  - configmap.yaml
+
+patches:
+  - target:
+      kind: Deployment
+      name: balancer
+    patch: |-
+      - op: add
+        path: /spec/template/spec/containers/0/envFrom/-
+        value:
+          configMapRef:
+            name: balancer-db-config
+      - op: add
+        path: /spec/template/spec/containers/0/env
+        value:
+          - name: SQL_PASSWORD
+            valueFrom:
+              secretKeyRef:
+                name: balancer-db-credentials
+                key: password