fix #130 - wrong url provided to Prometheus (#150)

* fix #130 - wrong url provided to Prometheus

* Update src/charm.py

Co-authored-by: Leon <82407168+sed-i@users.noreply.github.com>

* update grafana_dashboard.py lib

* remove comment

---------

Co-authored-by: Leon <82407168+sed-i@users.noreply.github.com>

src/charm.py

@@ -139,7 +139,13 @@ def __init__(self, *args):
             self,
             relation_name="self-metrics-endpoint",
             jobs=self.self_scraping_job,
-            external_url=self._external_url,
+            refresh_event=[
+                self.on.update_status,
+                self.ingress.on.ready,
+                self.ingress.on.revoked,
+                self.on["ingress"].relation_changed,
+                self.on["ingress"].relation_departed,
+            ],
         )
 
         self.catalog = CatalogueConsumer(
@@ -192,10 +198,11 @@ def __init__(self, *args):
     @property
     def self_scraping_job(self):
         """The self-monitoring scrape job."""
-        port = urlparse(self._external_url).port or 80
+        external_url = urlparse(self._external_url)
         return [
             {
-                "static_configs": [{"targets": [f"*:{port}"]}],
+                "metrics_path": f"{external_url.path}/metrics",
+                "static_configs": [{"targets": [f"{external_url.hostname}:{external_url.port}"]}],
             }
         ]
 

tests/unit/test_external_url.py

@@ -71,10 +71,12 @@ def test_config_option_overrides_fqdn(self):
         # GIVEN a charm with the fqdn as its external URL
         self.assertEqual(self.get_url_cli_arg(), self.fqdn_url)
         self.assertTrue(self.is_service_running())
+        self.assertEqual(self.fqdn_url, self.harness.charm._external_url)
 
         # WHEN the web_external_url config option is set
         external_url = "http://foo.bar:8080/path/to/alertmanager"
         self.harness.update_config({"web_external_url": external_url})
+        self.assertEqual(external_url, self.harness.charm._external_url)
 
         # THEN it is used as the cli arg instead of the fqdn
         self.assertEqual(self.get_url_cli_arg(), external_url)
@@ -95,6 +97,7 @@ def test_config_option_overrides_traefik(self):
         # GIVEN a charm with the fqdn as its external URL
         self.assertEqual(self.get_url_cli_arg(), self.fqdn_url)
         self.assertTrue(self.is_service_running())
+        self.assertEqual(self.harness.charm._external_url, self.fqdn_url)
 
         # WHEN a relation with traefik is formed but ingress isn't ready
         rel_id = self.harness.add_relation("ingress", "traefik-app")
@@ -103,6 +106,7 @@ def test_config_option_overrides_traefik(self):
         # THEN there is no change to the cli arg
         self.assertEqual(self.get_url_cli_arg(), self.fqdn_url)
         self.assertTrue(self.is_service_running())
+        self.assertEqual(self.harness.charm._external_url, self.fqdn_url)
 
         # WHEN ingress becomes available
         external_url_ingress = "http://foo.bar.ingress:80/path/to/mdl-alertmanager-k8s"