Upgrade PostgreSQL from 10 to 12

installer/roles/kubernetes/templates/postgresql-values.yml.j2

@@ -36,11 +36,14 @@ master:
 {% endif %}
 image:
 {% if pg_image_registry is defined %}
+# The default bitnami image from the chart doesn't work on ARM
   registry: {{ pg_image_registry }}
 {% endif %}
-  # The default bitnami image from the chart doesn't work on ARM
-  repository: postgres
-  tag: '11'
+{% if pg_image_registry is not defined %}
+  registry: docker.io/bitnami
+{% endif %}
+  repository: postgresql
+  tag: '12.5.0'
 volumePermissions:
   image:
 {% if pg_image_registry is defined %}