Add prefix-databases field

Author: dragomirp

docs/json_schemas/postgresql_client/v0/provider.json

@@ -200,6 +200,22 @@
             "alphanum-32byte-random"
           ],
           "title": "Entity password"
+        },
+        "prefix-databases": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ],
+          "default": null,
+          "description": "Comma separated list of databases matching a requested prefix",
+          "examples": [
+            "db1,db2"
+          ],
+          "title": "Entity password"
         }
       },
       "required": [

interfaces/postgresql_client/v0/README.md

@@ -44,6 +44,7 @@ If any side, Provider or Requirer doesn't support Juju Secrets, sensitive inform
 - Is expected to express (via `external-node-connectivity`) whether external connectivity requests are to be respected or not, in case the charm is capable of such.
 - May require delays (via `subordinated`) to provide service on Requirer scale up. If so, it is expected to set unit level `state` data when it is `ready` to serve.
 - May respect the `entity-name` and `password` set in `requested-entity-secret`.
+- Is expected to populate `prefix-databases`, if a prefix was requested and any databases match the prefix.
 
 ### Requirer
 
@@ -60,6 +61,7 @@ If any side, Provider or Requirer doesn't support Juju Secrets, sensitive inform
 - Is expected to respect the `subordinated` flag when scaling up and start emitting events only once unit level `state` is `ready`.
 - May require external connectivity (via `external-node-connectivity`).
 - May request specific entity credentials inside a secret set as `requested-entity-secret` field. Expected values in the secret are `entity-name` and an optional `password`. The requirer must be able to handle the requested values for `entity-name` and `password` not being respected.
+- May request a prefix in the `database` field, ending in `*` and containing at least three additional characters, for the provider to match.
 
 ## Relation Data
 

interfaces/postgresql_client/v0/schema.py

@@ -113,6 +113,14 @@ class PostgreSQLProviderData(BaseModel):
         title="Entity password",
     )
 
+    prefix_databases: Optional[str] = Field(
+        None,
+        alias="prefix-databases",
+        description="Comma separated databases matching the requested prefix",
+        examples=["database1,database2"],
+        title="Prefix databases",
+    )
+
 
 class PostgreSQLRequirerData(BaseModel):
     """The databag for the requirer side of this interface."""