milvus: add container-based config discovery support (DataDog#24319)

* milvus: add container-based config discovery support

Add an openmetrics_from_ports discovery strategy (port hint 9091) and an
auto_conf.yaml Autodiscovery template so the Agent can discover Milvus
containers automatically, plus e2e coverage for the generated candidates.

Environment: Datadog workspace

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* milvus: add changelog entry for discovery support

Environment: Datadog workspace

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

* fix

* Update milvus/changelog.d/24319.added

Co-authored-by: dkirov-dd <166512750+dkirov-dd@users.noreply.github.com>

---------

Co-authored-by: Claude Sonnet 5 <noreply@anthropic.com>
Co-authored-by: dkirov-dd <166512750+dkirov-dd@users.noreply.github.com>

Author: 3 people

milvus/assets/configuration/spec.yaml

@@ -2,6 +2,12 @@ name: Milvus
 fleet_configurable: true
 files:
 - name: milvus.yaml
+  discovery:
+    strategies:
+    - template: discovery/openmetrics_from_ports
+      overrides:
+        port_hints:
+        - 9091
   options:
     - template: init_config
       options:
@@ -19,3 +25,10 @@ files:
       - type: docker
         source: milvus
         service: <SERVICE>
+- name: auto_conf.yaml
+  options:
+  - template: ad_identifiers
+    overrides:
+      value.example:
+      - milvus
+  - template: auto_conf/discovery

milvus/changelog.d/24319.added

@@ -0,0 +1 @@
+Add container-based config discovery support.

milvus/datadog_checks/milvus/config_models/discovery.py

@@ -0,0 +1,42 @@
+# (C) Datadog, Inc. 2026-present
+# All rights reserved
+# Licensed under a 3-clause BSD style license (see LICENSE)
+
+# This file is autogenerated.
+# To change this file you should edit assets/configuration/spec.yaml and then run the following commands:
+#     ddev -x validate config -s <INTEGRATION_NAME>
+#     ddev -x validate models -s <INTEGRATION_NAME>
+
+from __future__ import annotations
+
+from collections.abc import Iterator
+from typing import Any
+
+from datadog_checks.base.utils.discovery import Service, candidate_ports
+from datadog_checks.milvus.config_models import discovery_overrides
+from datadog_checks.milvus.config_models.instance import InstanceConfig
+from datadog_checks.milvus.config_models.shared import SharedConfig
+
+
+def _generated_candidates(service: Service) -> Iterator[dict[str, Any]]:
+    shared = SharedConfig.model_validate({}, context={'configured_fields': frozenset()}).model_dump(
+        by_alias=True, mode='json', exclude_none=True
+    )
+    # discovery[0]: from_ports
+    for port in candidate_ports(service, [9091]):
+        ctx = {'port': port}
+        instance_data = {
+            'openmetrics_endpoint': 'http://{service.host}:{port.number}/metrics'.format(service=service, **ctx),
+        }
+        instance = InstanceConfig.model_validate(
+            instance_data, context={'configured_fields': frozenset(instance_data)}
+        ).model_dump(by_alias=True, mode='json', exclude_none=True)
+        yield {'init_config': shared, 'instances': [instance]}
+
+
+def candidates(service: Service) -> Iterator[dict[str, Any]]:
+    override = getattr(discovery_overrides, 'candidates', None)
+    if override is None:
+        yield from _generated_candidates(service)
+    else:
+        yield from override(service, default=_generated_candidates)

milvus/datadog_checks/milvus/config_models/discovery_overrides.py

@@ -0,0 +1,11 @@
+# (C) Datadog, Inc. 2026-present
+# All rights reserved
+# Licensed under a 3-clause BSD style license (see LICENSE)
+# Override the generated discovery candidates() for this integration.
+#
+# Define a candidates(service, default) function to wrap or replace the generated
+# candidate generation. `default` is the generated generator; call it to reuse
+# the spec-driven candidates, or ignore it to replace them entirely.
+#
+# def candidates(service, default):
+#     yield from default(service)

milvus/datadog_checks/milvus/config_models/discovery_strategies.py

@@ -0,0 +1,17 @@
+# (C) Datadog, Inc. 2026-present
+# All rights reserved
+# Licensed under a 3-clause BSD style license (see LICENSE)
+# Here you can define custom (local:) discovery strategies for this integration.
+#
+# Decorate a generator with @discovery_strategy (imported from
+# datadog_checks.base.utils.discovery) and reference it from the spec discovery
+# stanza as `strategy: local:<function_name>`. The function receives the
+# discovered Service plus the inputs declared in the spec and yields one context
+# (ctx) mapping per candidate, exposing the keys listed in `provides`.
+#
+# from datadog_checks.base.utils.discovery import discovery_strategy
+#
+# @discovery_strategy(provides=('svc',))
+# def from_some_config(service, config_path):
+#     ...
+#     yield {'svc': ...}

milvus/datadog_checks/milvus/data/auto_conf.yaml

@@ -0,0 +1,19 @@
+## @param ad_identifiers - list of strings - required
+## A list of container identifiers that are used by Autodiscovery to identify
+## which container the check should be run against. For more information, see:
+## https://docs.datadoghq.com/agent/guide/ad_identifiers/
+#
+ad_identifiers:
+  - milvus
+
+## Enables configuration discovery
+#
+discovery: {}
+
+## Unused init configuration
+#
+init_config:
+
+## Unused instance configuration
+#
+instances: []

milvus/tests/conftest.py

@@ -6,7 +6,7 @@
 
 import pytest
 
-from datadog_checks.dev import docker_run
+from datadog_checks.dev import docker_run, get_e2e_discovery_metadata
 from datadog_checks.dev.conditions import CheckDockerLogs, CheckEndpoints
 
 from . import common
@@ -23,9 +23,12 @@ def dd_environment():
     ]
     logging.info(conditions)
     with docker_run(compose_file, conditions=conditions):
-        yield {
-            'instances': [common.MOCKED_INSTANCE],
-        }
+        yield (
+            {
+                'instances': [common.MOCKED_INSTANCE],
+            },
+            get_e2e_discovery_metadata(),
+        )
 
 
 @pytest.fixture

milvus/tests/test_e2e.py

@@ -4,20 +4,45 @@
 import pytest
 
 from datadog_checks.base.constants import ServiceCheck
+from datadog_checks.dev.docker import CONTAINER_STABILITY_LOG_PATTERNS, assert_all_discovery_candidates_stable
+from datadog_checks.milvus import MilvusCheck
 
 from . import common
 
+SKIPPED_METRICS = [
+    'milvus.datacoord.import_tasks',
+    'milvus.datacoord.index.task',
+]  # these metrics need a more complex setup to appear
+
+# Milvus standalone logs benign "error"-keyed WARN messages while its internal coordinators
+# come up asynchronously (e.g. etcd leader elections, gRPC clients retrying until ready), so the
+# generic "error" pattern is dropped in favor of the more specific crash indicators.
+DISCOVERY_STABILITY_LOG_PATTERNS = tuple(pattern for pattern in CONTAINER_STABILITY_LOG_PATTERNS if pattern != 'error')
 
-@pytest.mark.e2e
-def test_check_milvus_e2e(dd_agent_check, instance):
-    aggregator = dd_agent_check(instance, rate=True)
 
-    for metric, _ in common.STANDALONE_TEST_METRICS.items():
-        if metric in [
-            'milvus.datacoord.import_tasks',
-            'milvus.datacoord.index.task',
-        ]:  # these metrics need a more complex setup to appear
+def assert_standalone_metrics(aggregator):
+    for metric in common.STANDALONE_TEST_METRICS:
+        if metric in SKIPPED_METRICS:
             continue
         aggregator.assert_metric(name=metric)
 
     aggregator.assert_service_check('milvus.openmetrics.health', ServiceCheck.OK)
+
+
+@pytest.mark.e2e
+def test_check_milvus_e2e(dd_agent_check, instance):
+    aggregator = dd_agent_check(instance, rate=True)
+    assert_standalone_metrics(aggregator)
+
+
+@pytest.mark.e2e
+def test_e2e_discovery(dd_agent_check_discovery):
+    aggregator = dd_agent_check_discovery(rate=True)
+    assert_standalone_metrics(aggregator)
+
+
+@pytest.mark.e2e
+def test_e2e_discovery_all_candidates(dd_agent_check):
+    assert_all_discovery_candidates_stable(
+        dd_agent_check, MilvusCheck, compose_service='milvus', log_patterns=DISCOVERY_STABILITY_LOG_PATTERNS
+    )