pass in mock opener to controlsocket client

src/charm.py

@@ -6,12 +6,12 @@
 import logging
 import secrets
 import yaml
+from charms.prometheus_k8s.v0.prometheus_scrape import MetricsEndpointProvider
 from ops.charm import CharmBase
 from ops.framework import StoredState
 from ops.charm import RelationJoinedEvent, RelationDepartedEvent
 from ops.main import main
 from ops.model import ActiveStatus, BlockedStatus, Relation
-from charms.prometheus_k8s.v0.prometheus_scrape import MetricsEndpointProvider
 
 logger = logging.getLogger(__name__)
 

tests/test_charm.py

@@ -3,13 +3,13 @@
 
 import os
 import unittest
-from unittest.mock import mock_open, patch
-
 from charm import JujuControllerCharm
 from ops.testing import Harness
+from unittest.mock import mock_open, patch
 
 agent_conf = '''
 apiport: 17070
+cacert: fake
 '''
 
 
@@ -51,12 +51,25 @@ def test_website_relation_joined(self, open, ingress_address):
         self.assertEqual(data["private-address"], "192.168.1.17")
         self.assertEqual(data["port"], '17070')
 
-    def test_metrics_endpoint_relation_created(self):
+    @patch("builtins.open", new_callable=mock_open, read_data=agent_conf)
+    def test_metrics_endpoint_relation_created(self, open):
         harness = Harness(JujuControllerCharm)
         self.addCleanup(harness.cleanup)
         harness.begin()
 
-        # harness.add_relation('metrics-endpoint', 'prometheus-k8s')
+        mock_opener = mockOpener(self)
+        harness.charm.control_socket.opener = mock_opener
+
+        mock_opener.expect(
+            url='http://localhost/metrics-users',
+            method='POST',
+            # TODO: test body
+            response=mockResponse(
+                headers=mockHeaders(content_type='application/json'),
+                body='{"message":"created user \\"juju-metrics-r0\\""}'
+            )
+        )
+        harness.add_relation('metrics-endpoint', 'prometheus-k8s')
 
     # def test_metrics_endpoint_relation_broken(self):
 
@@ -69,3 +82,41 @@ def __init__(self, address):
 class mockNetwork:
     def __init__(self, address):
         self.ingress_address = address
+
+
+class mockOpener:
+    def __init__(self, test_case):
+        self.test = test_case
+
+    def expect(self, url, method, response):
+        self.url = url
+        self.method = method
+
+        self.response = response
+
+    def open(self, request, timeout):
+        self.test.assertEqual(request.full_url, self.url)
+        self.test.assertEqual(request.method, self.method)
+
+        return self.response
+
+
+class mockResponse():
+    def __init__(self, headers, body):
+        self.headers = headers
+        self.body = body
+
+    def read(self):
+        return self.body
+
+
+class mockHeaders():
+    def __init__(self, content_type, params=None):
+        self.content_type = content_type
+        self.params = params
+
+    def get_content_type(self):
+        return self.content_type
+
+    def get_params(self):
+        return self.params