1 files changed, 93 insertions, 0 deletions
diff --git a/src/pybind/mgr/prometheus/test_module.py b/src/pybind/mgr/prometheus/test_module.py
new file mode 100644
index 000000000..0647cb658
--- /dev/null
+++ b/src/pybind/mgr/prometheus/test_module.py
@@ -0,0 +1,93 @@
+from typing import Dict
+from unittest import TestCase
+
+from prometheus.module import Metric, LabelValues, Number
+
+
+class MetricGroupTest(TestCase):
+    def setUp(self):
+        self.DISK_OCCUPATION = (
+            "ceph_daemon",
+            "device",
+            "db_device",
+            "wal_device",
+            "instance",
+        )
+        self.metric_value: Dict[LabelValues, Number] = {
+            ("osd.0", "/dev/dm-0", "", "", "node1"): 1,
+            ("osd.1", "/dev/dm-0", "", "", "node3"): 1,
+            ("osd.2", "/dev/dm-0", "", "", "node2"): 1,
+            ("osd.3", "/dev/dm-1", "", "", "node1"): 1,
+            ("osd.4", "/dev/dm-1", "", "", "node3"): 1,
+            ("osd.5", "/dev/dm-1", "", "", "node2"): 1,
+            ("osd.6", "/dev/dm-1", "", "", "node2"): 1,
+        }
+
+    def test_metric_group_by(self):
+        m = Metric("untyped", "disk_occupation", "", self.DISK_OCCUPATION)
+        m.value = self.metric_value
+        grouped_metric = m.group_by(
+            ["device", "instance"],
+            {"ceph_daemon": lambda xs: "+".join(xs)},
+            name="disk_occupation_display",
+        )
+        self.assertEqual(
+            grouped_metric.value,
+            {
+                ("osd.0", "/dev/dm-0", "node1"): 1,
+                ("osd.1", "/dev/dm-0", "node3"): 1,
+                ("osd.2", "/dev/dm-0", "node2"): 1,
+                ("osd.3", "/dev/dm-1", "node1"): 1,
+                ("osd.4", "/dev/dm-1", "node3"): 1,
+                ("osd.5+osd.6", "/dev/dm-1", "node2"): 1,
+            },
+        )
+        self.maxDiff = None
+        self.assertEqual(
+            grouped_metric.str_expfmt(),
+            """
+# HELP ceph_disk_occupation_display 
+# TYPE ceph_disk_occupation_display untyped
+ceph_disk_occupation_display{ceph_daemon="osd.0",device="/dev/dm-0",instance="node1"} 1.0
+ceph_disk_occupation_display{ceph_daemon="osd.1",device="/dev/dm-0",instance="node3"} 1.0
+ceph_disk_occupation_display{ceph_daemon="osd.2",device="/dev/dm-0",instance="node2"} 1.0
+ceph_disk_occupation_display{ceph_daemon="osd.3",device="/dev/dm-1",instance="node1"} 1.0
+ceph_disk_occupation_display{ceph_daemon="osd.4",device="/dev/dm-1",instance="node3"} 1.0
+ceph_disk_occupation_display{ceph_daemon="osd.5+osd.6",device="/dev/dm-1",instance="node2"} 1.0""",  # noqa: W291
+        )
+        self.assertEqual(
+            grouped_metric.labelnames, ("ceph_daemon", "device", "instance")
+        )
+
+    def test_metric_group_by__no_value(self):
+        m = Metric("metric_type", "name", "desc", labels=('foo', 'bar'))
+        grouped = m.group_by(['foo'], {'bar': lambda bars: ', '.join(bars)})
+        self.assertEqual(grouped.value, {})
+        self.assertEqual(grouped.str_expfmt(),
+                         '\n# HELP ceph_name desc\n# TYPE ceph_name metric_type')
+
+    def test_metric_group_by__no_labels(self):
+        m = Metric("metric_type", "name", "desc", labels=None)
+        with self.assertRaises(AssertionError) as cm:
+            m.group_by([], {})
+        self.assertEqual(str(cm.exception), "cannot match keys without label names")
+
+    def test_metric_group_by__key_not_in_labels(self):
+        m = Metric("metric_type", "name", "desc", labels=("foo", "bar"))
+        m.value = self.metric_value
+        with self.assertRaises(AssertionError) as cm:
+            m.group_by(["baz"], {})
+        self.assertEqual(str(cm.exception), "unknown key: baz")
+
+    def test_metric_group_by__empty_joins(self):
+        m = Metric("", "", "", ("foo", "bar"))
+        with self.assertRaises(AssertionError) as cm:
+            m.group_by(["foo"], joins={})
+        self.assertEqual(str(cm.exception), "joins must not be empty")
+
+    def test_metric_group_by__joins_not_callable(self):
+        m = Metric("", "", "", ("foo", "bar"))
+        m.value = self.metric_value
+        with self.assertRaises(AssertionError) as cm:
+            m.group_by(["foo"], {"bar": "not callable str"})
+        self.assertEqual(str(cm.exception), "joins must be callable")