Add config option for log_level

charmcraft.yaml

@@ -210,6 +210,13 @@ config:
         Ref: https://grafana.com/docs/agent/latest/static/configuration/flags/#report-information-usage
       type: boolean
       default: true
+    log_level:
+      description: |
+        Grafana Agent server log level (only log messages with the given severity
+        or above). Must be one of: [debug, info, warn, error].
+        If not set, the Grafana Agent default (info) will be used.
+      type: string
+      default: info
     path_exclude:
       description: >
         Glob for a set of log files present in `/var/log` that should be ignored by Grafana Agent.

src/grafana_agent.py

@@ -12,7 +12,7 @@
 import socket
 from collections import namedtuple
 from dataclasses import dataclass
-from typing import Any, Callable, Dict, List, Optional, Set, Union
+from typing import Any, Callable, Dict, List, Optional, Set, Union, cast
 
 import yaml
 from charms.certificate_transfer_interface.v0.certificate_transfer import (
@@ -150,6 +150,7 @@ def __init__(self, *args):
 
         for rules in [self.loki_rules_paths, self.dashboard_paths]:
             if not os.path.isdir(rules.dest):
+                rules.src.mkdir(parents=True, exist_ok=True)
                 shutil.copytree(rules.src, rules.dest, dirs_exist_ok=True)
 
         self._remote_write = PrometheusRemoteWriteConsumer(
@@ -750,7 +751,7 @@ def _server_config(self) -> dict:
         Returns:
             The dict representing the config
         """
-        server_config: Dict[str, Any] = {"log_level": "info"}
+        server_config: Dict[str, Any] = {"log_level": self.log_level}
         if self.cert.enabled:
             server_config["http_tls_config"] = self.tls_config
             server_config["grpc_tls_config"] = self.tls_config
@@ -1066,6 +1067,21 @@ def _instance_name(self) -> str:
 
         return socket.getfqdn()
 
+    @property
+    def log_level(self) -> str:
+        """The log level configured for the charm."""
+        # Valid upstream log levels in server_config
+        # https://grafana.com/docs/agent/latest/static/configuration/server-config/#server_config
+        allowed_log_levels = ["debug", "info", "warn", "error"]
+        log_level = cast(str, self.config.get("log_level")).lower()
+
+        if log_level not in allowed_log_levels:
+            logging.warning(
+                f'Invalid loglevel: {log_level} given, {"/".join(allowed_log_levels)} allowed. defaulting to INFO loglevel.'
+            )
+            log_level = "info"
+        return log_level
+
     def _reload_config(self, attempts: int = 10) -> None:
         """Reload the config file.
 

tests/scenario/conftest.py

@@ -1,19 +1,48 @@
-import shutil
-from pathlib import Path, PosixPath
+# Copyright 2022 Canonical Ltd.
+# See LICENSE file for licensing details.
+from unittest.mock import PropertyMock, patch
 
 import pytest
+from charms.tempo_coordinator_k8s.v0.charm_tracing import charm_tracing_disabled
 
-from tests.scenario.helpers import CHARM_ROOT
 
+@pytest.fixture
+def placeholder_cfg_path(tmp_path):
+    return tmp_path / "foo.yaml"
 
-class Vroot(PosixPath):
-    def clean(self) -> None:
-        shutil.rmtree(self)
-        shutil.copytree(CHARM_ROOT / "src", self / "src")
 
+@pytest.fixture()
+def mock_config_path(placeholder_cfg_path):
+    with patch("grafana_agent.CONFIG_PATH", placeholder_cfg_path):
+        yield
 
-@pytest.fixture
-def vroot(tmp_path) -> Path:
-    vroot = Vroot(str(tmp_path.absolute()))
-    vroot.clean()
-    return vroot
+
+@pytest.fixture(autouse=True)
+def mock_snap():
+    """Mock the charm's snap property so we don't access the host."""
+    with patch("charm.GrafanaAgentMachineCharm.snap", new_callable=PropertyMock):
+        yield
+
+
+@pytest.fixture(autouse=True)
+def mock_refresh():
+    """Mock the refresh call so we don't access the host."""
+    with patch("snap_management._install_snap", new_callable=PropertyMock):
+        yield
+
+
+CONFIG_MATRIX = [
+    {"classic_snap": True},
+    {"classic_snap": False},
+]
+
+
+@pytest.fixture(params=CONFIG_MATRIX)
+def charm_config(request):
+    return request.param
+
+
+@pytest.fixture(autouse=True)
+def mock_charm_tracing():
+    with charm_tracing_disabled():
+        yield

tests/scenario/helpers.py

@@ -1,12 +1,15 @@
 # Copyright 2023 Canonical Ltd.
 # See LICENSE file for licensing details.
-from pathlib import Path
-
-import yaml
-
-CHARM_ROOT = Path(__file__).parent.parent.parent
-
-
-def get_charm_meta(charm_type) -> dict:
-    raw_meta = (CHARM_ROOT / "charmcraft").with_suffix(".yaml").read_text()
-    return yaml.safe_load(raw_meta)
+from unittest.mock import MagicMock
+
+
+def set_run_out(mock_run, returncode: int = 0, stdout: str = "", stderr: str = ""):
+    mock_stdout = MagicMock()
+    mock_stdout.configure_mock(
+        **{
+            "returncode": returncode,
+            "stdout.decode.return_value": stdout,
+            "stderr.decode.return_value": stderr,
+        }
+    )
+    mock_run.return_value = mock_stdout

tests/scenario/test_machine_charm/test_alert_labels.py → tests/scenario/test_alert_labels.py

@@ -4,7 +4,7 @@
 import json
 
 import pytest
-from scenario import Context, PeerRelation, Relation, State, SubordinateRelation
+from ops.testing import Context, PeerRelation, Relation, State, SubordinateRelation
 
 import charm
 
@@ -15,7 +15,7 @@ def use_mock_config_path(mock_config_path):
     yield
 
 
-def test_metrics_alert_rule_labels(vroot, charm_config):
+def test_metrics_alert_rule_labels(charm_config):
     """Check that metrics alert rules are labeled with principal topology."""
     cos_agent_primary_data = {
         "config": json.dumps(
@@ -97,9 +97,8 @@ def test_metrics_alert_rule_labels(vroot, charm_config):
     )
     remote_write_relation = Relation("send-remote-write", remote_app_name="prometheus")
 
-    context = Context(
+    ctx = Context(
         charm_type=charm.GrafanaAgentMachineCharm,
-        charm_root=vroot,
     )
     state = State(
         leader=True,
@@ -112,11 +111,13 @@ def test_metrics_alert_rule_labels(vroot, charm_config):
         config=charm_config,
     )
 
-    state_0 = context.run(event=cos_agent_primary_relation.changed_event, state=state)
-    state_1 = context.run(event=cos_agent_subordinate_relation.changed_event, state=state_0)
-    state_2 = context.run(event=remote_write_relation.joined_event, state=state_1)
+    state_0 = ctx.run(ctx.on.relation_changed(relation=cos_agent_primary_relation), state)
+    state_1 = ctx.run(ctx.on.relation_changed(relation=cos_agent_subordinate_relation), state_0)
+    state_2 = ctx.run(ctx.on.relation_joined(relation=remote_write_relation), state_1)
 
-    alert_rules = json.loads(state_2.relations[2].local_app_data["alert_rules"])
+    alert_rules = json.loads(
+        state_2.get_relation(remote_write_relation.id).local_app_data["alert_rules"]
+    )
     for group in alert_rules["groups"]:
         for rule in group["rules"]:
             if "grafana-agent_alertgroup_alerts" in group["name"]:

tests/scenario/test_config.py

@@ -0,0 +1,51 @@
+# Copyright 2023 Canonical Ltd.
+# See LICENSE file for licensing details.
+from unittest.mock import patch
+
+import pytest
+import yaml
+from ops.testing import Context, State
+
+import charm
+
+
+@pytest.fixture(autouse=True)
+def patch_all(placeholder_cfg_path):
+    with patch("grafana_agent.CONFIG_PATH", placeholder_cfg_path):
+        yield
+
+
+@pytest.mark.parametrize("log_level", ("debug", "info", "warn", "error"))
+def test_config_log_level(placeholder_cfg_path, log_level):
+    # GIVEN a GrafanaAgentMachineCharm
+    with patch("charm.GrafanaAgentMachineCharm.is_ready", True):
+        ctx = Context(charm_type=charm.GrafanaAgentMachineCharm)
+        # WHEN the config option for log_level is set to a VALID option
+        ctx.run(ctx.on.start(), State(config={"log_level": log_level}))
+
+    # THEN the config file has the correct server:log_level field
+    yaml_cfg = yaml.safe_load(placeholder_cfg_path.read_text())
+    assert yaml_cfg["server"]["log_level"] == log_level
+
+
+def test_default_config_log_level(placeholder_cfg_path):
+    # GIVEN a GrafanaAgentMachineCharm
+    with patch("charm.GrafanaAgentMachineCharm.is_ready", True):
+        ctx = Context(charm_type=charm.GrafanaAgentMachineCharm)
+        # WHEN the config option for log_level is set to an INVALID option
+        ctx.run(ctx.on.start(), State(config={"log_level": "foo"}))
+
+        # THEN Juju debug-log is created with WARNING level
+        found = False
+        for log in ctx.juju_log:
+            if (
+                "WARNING" == log.level
+                and "Invalid loglevel: foo given, debug/info/warn/error allowed." in log.message
+            ):
+                found = True
+                break
+        assert found is True
+
+    # AND the config file defaults the server:log_level field to "info"
+    yaml_cfg = yaml.safe_load(placeholder_cfg_path.read_text())
+    assert yaml_cfg["server"]["log_level"] == "info"

tests/scenario/test_machine_charm/test_cos_agent_e2e.py → tests/scenario/test_cos_agent_e2e.py

@@ -1,9 +1,6 @@
 # Copyright 2021 Canonical Ltd.
 # See LICENSE file for licensing details.
 import json
-import os
-import tempfile
-from pathlib import Path
 from unittest.mock import MagicMock, PropertyMock, patch
 
 import pytest
@@ -14,13 +11,7 @@
 )
 from ops.charm import CharmBase
 from ops.framework import Framework
-from scenario import Context, PeerRelation, State, SubordinateRelation
-
-
-@pytest.fixture
-def placeholder_cfg_path(tmp_path):
-    return tmp_path / "foo.yaml"
-
+from ops.testing import Context, PeerRelation, State, SubordinateRelation
 
 PROVIDER_NAME = "mock-principal"
 PROM_RULE = """alert: HostCpuHighIowait
@@ -59,28 +50,6 @@ def patch_all(placeholder_cfg_path):
         yield
 
 
-@pytest.fixture(autouse=True)
-def vroot(placeholder_cfg_path):
-    with tempfile.TemporaryDirectory() as vroot:
-        vroot = Path(vroot)
-        promroot = vroot / "src/prometheus_alert_rules"
-        lokiroot = vroot / "src/loki_alert_rules"
-        grafroot = vroot / "src/grafana_dashboards"
-
-        promroot.mkdir(parents=True)
-        lokiroot.mkdir(parents=True)
-        grafroot.mkdir(parents=True)
-
-        (promroot / "prom.rule").write_text(PROM_RULE)
-        (lokiroot / "loki.rule").write_text(LOKI_RULE)
-        (grafroot / "grafana_dashboard.json").write_text(GRAFANA_DASH)
-
-        old_cwd = os.getcwd()
-        os.chdir(str(vroot))
-        yield vroot
-        os.chdir(old_cwd)
-
-
 @pytest.fixture(autouse=True)
 def snap_is_installed():
     with patch(
@@ -140,22 +109,26 @@ def __init__(self, framework: Framework):
 
 
 @pytest.fixture
-def provider_ctx(provider_charm, vroot):
-    return Context(charm_type=provider_charm, meta=provider_charm.META, charm_root=vroot)
+def provider_ctx(provider_charm):
+    return Context(charm_type=provider_charm, meta=provider_charm.META)
 
 
 @pytest.fixture
-def requirer_ctx(requirer_charm, vroot):
-    return Context(charm_type=requirer_charm, meta=requirer_charm.META, charm_root=vroot)
+def requirer_ctx(requirer_charm):
+    return Context(charm_type=requirer_charm, meta=requirer_charm.META)
 
 
 def test_cos_agent_changed_no_remote_data(provider_ctx):
     cos_agent = SubordinateRelation("cos-agent")
+
     state_out = provider_ctx.run(
-        cos_agent.changed_event(remote_unit_id=1), State(relations=[cos_agent])
+        provider_ctx.on.relation_changed(relation=cos_agent, remote_unit=1),
+        State(relations=[cos_agent]),
     )
 
-    config = json.loads(state_out.relations[0].local_unit_data[CosAgentPeersUnitData.KEY])
+    config = json.loads(
+        state_out.get_relation(cos_agent.id).local_unit_data[CosAgentPeersUnitData.KEY]
+    )
     assert config["metrics_alert_rules"] == {}
     assert config["log_alert_rules"] == {}
     assert len(config["dashboards"]) == 1
@@ -187,14 +160,15 @@ def test_subordinate_update(requirer_ctx):
         remote_unit_data={"config": json.dumps(config)},
     )
     state_out1 = requirer_ctx.run(
-        cos_agent1.changed_event(remote_unit_id=0), State(relations=[cos_agent1, peer])
+        requirer_ctx.on.relation_changed(relation=cos_agent1, remote_unit=0),
+        State(relations=[cos_agent1, peer]),
     )
     peer_out = state_out1.get_relations("peers")[0]
     peer_out_data = json.loads(
         peer_out.local_unit_data[f"{CosAgentPeersUnitData.KEY}-mock-principal/0"]
     )
     assert peer_out_data["unit_name"] == f"{PROVIDER_NAME}/0"
-    assert peer_out_data["relation_id"] == str(cos_agent1.relation_id)
+    assert peer_out_data["relation_id"] == str(cos_agent1.id)
     assert peer_out_data["relation_name"] == cos_agent1.endpoint
 
     # passthrough as-is
@@ -210,19 +184,22 @@ def test_subordinate_update(requirer_ctx):
     assert "http://localhost:4318" in urls
 
 
-def test_cos_agent_wrong_rel_data(vroot, snap_is_installed, provider_ctx):
+def test_cos_agent_wrong_rel_data(snap_is_installed, provider_ctx):
     # Step 1: principal charm is deployed and ends in "unknown" state
     provider_ctx.charm_spec.charm_type._log_slots = (
         "charmed:frogs"  # Set wrong type, must be a list
     )
     cos_agent_rel = SubordinateRelation("cos-agent")
     state = State(relations=[cos_agent_rel])
-    state_out = provider_ctx.run(cos_agent_rel.changed_event(remote_unit_id=1), state=state)
+
+    state_out = provider_ctx.run(
+        provider_ctx.on.relation_changed(relation=cos_agent_rel, remote_unit=1), state
+    )
     assert state_out.unit_status.name == "unknown"
 
     found = False
     for log in provider_ctx.juju_log:
-        if "ERROR" in log[0] and "Invalid relation data provided:" in log[1]:
+        if "ERROR" == log.level and "Invalid relation data provided:" in log.message:
             found = True
             break