[snmp] aruba-clearpass: fix metric_type for memory/disk metrics (DataDog#23791)

* [snmp] Mirror backend tag enrichment in e2e tests

* [snmp] Fix aruba-clearpass memory disk metric types

* [snmp] Test aruba-clearpass capacity metric types

* [snmp] Move aruba-clearpass metric type assertion into e2e test

Author: FlorianVeaux

snmp/changelog.d/23791.fixed

@@ -0,0 +1 @@
+Breaking change: Fixed metric type for `snmp.cppmSystemMemoryFree`, `snmp.cppmSystemMemoryTotal`, `snmp.cppmSystemDiskSpaceFree`, and `snmp.cppmSystemDiskSpaceTotal` in the aruba-clearpass profile. These were previously submitted as rates due to their underlying `Counter64` SNMP type, producing incorrect values. They are now submitted as gauges. Customers with existing dashboards or monitors on these metrics will see a discontinuity between historical rate datapoints and new gauge datapoints; please rebuild any affected widgets or monitors.

snmp/datadog_checks/snmp/data/default_profiles/aruba-clearpass.yaml

@@ -23,12 +23,16 @@ metrics:
     symbols:
       - name: cppmSystemMemoryTotal
         OID: 1.3.6.1.4.1.14823.1.6.1.1.1.1.1.12
+        metric_type: gauge
       - name: cppmSystemMemoryFree
         OID: 1.3.6.1.4.1.14823.1.6.1.1.1.1.1.13
+        metric_type: gauge
       - name: cppmSystemDiskSpaceTotal
         OID: 1.3.6.1.4.1.14823.1.6.1.1.1.1.1.14
+        metric_type: gauge
       - name: cppmSystemDiskSpaceFree
         OID: 1.3.6.1.4.1.14823.1.6.1.1.1.1.1.15
+        metric_type: gauge
     metric_tags:
       - symbol:
           OID: 1.3.6.1.4.1.14823.1.6.1.1.1.1.1.4

snmp/tests/test_e2e_core_profiles/test_profile_aruba_clearpass.py

@@ -5,6 +5,7 @@
 import pytest
 
 from datadog_checks.dev.utils import get_metadata_metrics
+from datadog_checks.snmp.utils import get_profile_definition
 
 from .. import common
 from ..test_e2e_core_metadata import assert_device_metadata
@@ -19,9 +20,30 @@
 
 pytestmark = [pytest.mark.e2e, common.py3_plus_only, common.snmp_integration_only]
 
+CPPM_CAPACITY_METRIC_TYPES = {
+    'cppmSystemMemoryFree': 'gauge',
+    'cppmSystemMemoryTotal': 'gauge',
+    'cppmSystemDiskSpaceFree': 'gauge',
+    'cppmSystemDiskSpaceTotal': 'gauge',
+}
+
+
+def assert_cppm_capacity_metrics_are_forced_to_gauge(profile):
+    profile_definition = get_profile_definition({'definition_file': '{}.yaml'.format(profile)})
+    metric_types = {}
+    for metric in profile_definition['metrics']:
+        for symbol in metric.get('symbols', []):
+            name = symbol['name']
+            if name in CPPM_CAPACITY_METRIC_TYPES:
+                metric_types[name] = symbol.get('metric_type')
+
+    assert metric_types == CPPM_CAPACITY_METRIC_TYPES
+
 
 def test_e2e_profile_aruba_clearpass(dd_agent_check):
     profile = 'aruba-clearpass'
+    assert_cppm_capacity_metrics_are_forced_to_gauge(profile)
+
     config = create_e2e_core_test_config(profile)
     aggregator = common.dd_agent_check_wrapper(dd_agent_check, config, rate=True)