feat(COS): implement bundle relations, log on promtail-digest-error, …

…expose metrics port on OpenFGA service

src/charm.py

@@ -27,7 +27,7 @@
     DatabaseRequires,
 )
 from charms.grafana_k8s.v0.grafana_dashboard import GrafanaDashboardProvider
-from charms.loki_k8s.v0.loki_push_api import LogProxyConsumer
+from charms.loki_k8s.v0.loki_push_api import LogProxyConsumer, PromtailDigestError
 from charms.observability_libs.v1.kubernetes_service_patch import KubernetesServicePatch
 from charms.openfga_k8s.v1.openfga import OpenFGAProvider, OpenFGAStoreRequestEvent
 from charms.prometheus_k8s.v0.prometheus_scrape import MetricsEndpointProvider
@@ -68,7 +68,7 @@
     PEER_KEY_DB_MIGRATE_VERSION,
     REQUIRED_SETTINGS,
     SERVICE_NAME,
-    WORKLOAD_CONTAINER,
+    WORKLOAD_CONTAINER, OPENFGA_METRICS_HTTP_PORT,
 )
 from openfga import OpenFGA
 from state import State, requires_state, requires_state_setter
@@ -111,14 +111,22 @@ def __init__(self, *args: Any) -> None:
             self,
             log_files=[LOG_FILE],
             relation_name=LOG_PROXY_RELATION_NAME,
-            promtail_resource_name="promtail-bin",
-            container_name=WORKLOAD_CONTAINER,
+            container_name=WORKLOAD_CONTAINER
         )
 
         # Prometheus metrics endpoint relation
         self.metrics_endpoint = MetricsEndpointProvider(
             self,
-            jobs=[{"static_configs": [{"targets": [f"*:{OPENFGA_SERVER_HTTP_PORT}"]}]}],
+            jobs=[
+                {
+                    "metrics_path": "/metrics",
+                    "static_configs": [
+                        {
+                            "targets": [f"*:{OPENFGA_METRICS_HTTP_PORT}"]
+                        }
+                    ]
+                }
+            ],
             refresh_event=self.on.config_changed,
             relation_name=METRIC_RELATION_NAME,
         )
@@ -161,14 +169,18 @@ def __init__(self, *args: Any) -> None:
             self._on_database_changed,
         )
         self.framework.observe(self.on.database_relation_broken, self._on_database_relation_broken)
+        self.framework.observe(self.log_proxy.on.promtail_digest_error, self._on_promtail_digest_error)
 
         port_http = ServicePort(
             OPENFGA_SERVER_HTTP_PORT, name=f"{self.app.name}-http", protocol="TCP"
         )
         port_grpc = ServicePort(
             OPENFGA_SERVER_GRPC_PORT, name=f"{self.app.name}-grpc", protocol="TCP"
         )
-        self.service_patcher = KubernetesServicePatch(self, [port_http, port_grpc])
+        port_metrics = ServicePort(
+            OPENFGA_METRICS_HTTP_PORT, name=f"{self.app.name}-metrics", protocol="TCP"
+        )
+        self.service_patcher = KubernetesServicePatch(self, [port_http, port_grpc, port_metrics])
 
     def _on_openfga_pebble_ready(self, event: PebbleReadyEvent) -> None:
         """Workload pebble ready."""
@@ -212,6 +224,10 @@ def _get_database_relation_info(self) -> Optional[Dict]:
             "database_name": DATABASE_NAME,
         }
 
+    def _on_promtail_digest_error(self, event: PromtailDigestError) -> None:
+        """ Log PromtailDigestError error """
+        logger.error(f'got PromtailDigestError with message: "{event.message}"')
+
     @property
     def _log_level(self) -> str:
         return self.config["log-level"]

src/constants.py

@@ -11,9 +11,10 @@
     "OPENFGA_AUTHN_PRESHARED_KEYS",
 ]
 
-LOG_FILE = "/var/log/openfga-k8s"
+LOG_FILE = "/openfga-k8s.log"
 
 OPENFGA_SERVER_HTTP_PORT = 8080
+OPENFGA_METRICS_HTTP_PORT = 2112
 OPENFGA_SERVER_GRPC_PORT = 8081
 
 PEER_KEY_DB_MIGRATE_VERSION = "db_migrate_version"