[DPE-4861] Avoid ambiguous service selector when multiple mysql apps in a model have the same cluster-name (#501)

* Avoid ambiguous service selector when multiple mysql apps in a model have the same cluster-name

* Use hyphen instead of underscore

* Fix failing unit test

Author: shayancanonical

src/k8s_helpers.py

@@ -54,7 +54,11 @@ def create_endpoint_services(self, roles: List[str]) -> None:
             roles: List of roles to append on the service name
         """
         for role in roles:
-            selector = {"cluster-name": self.cluster_name, "role": role}
+            selector = {
+                "cluster-name": self.cluster_name,
+                "application-name": self.app_name,
+                "role": role,
+            }
             service_name = f"{self.app_name}-{role}"
             pod0 = self.client.get(
                 res=Pod,
@@ -128,6 +132,7 @@ def label_pod(self, role: str, pod_name: Optional[str] = None) -> None:
             logger.debug(f"Patching {pod_name=} with {role=}")
 
             pod.metadata.labels["cluster-name"] = self.cluster_name
+            pod.metadata.labels["application-name"] = self.app_name
             pod.metadata.labels["role"] = role
             self.client.patch(Pod, pod_name, pod)
         except ApiError as e:

tests/unit/test_k8s_helpers.py

@@ -49,6 +49,7 @@ def test_create_endpoint_service(self, _create):
                 spec=ServiceSpec(
                     selector={
                         "cluster-name": self.harness.charm.app_peer_data.get("cluster-name"),
+                        "application-name": self.harness.charm.model.app.name,
                         "role": "role1",
                     },
                     ports=[ServicePort(port=3306, targetPort=3306)],