process autodiscovery for krakend

Author: vitkyrka

datadog_checks_dev/changelog.d/24238.added

@@ -0,0 +1 @@
+Add process autodiscovery E2E testing helpers.

datadog_checks_dev/datadog_checks/dev/__init__.py

@@ -3,7 +3,7 @@
 # Licensed under a 3-clause BSD style license (see LICENSE)
 from .__about__ import __version__
 from .conditions import WaitFor
-from .docker import docker_run, get_docker_hostname, get_e2e_discovery_metadata
+from .docker import docker_run, get_docker_hostname, get_e2e_discovery_metadata, get_e2e_process_discovery_metadata
 from .env import environment_run
 from .errors import RetryError
 from .fs import chdir, get_here, temp_chdir, temp_dir

datadog_checks_dev/datadog_checks/dev/docker.py

@@ -229,6 +229,13 @@ def _assert_no_log_patterns(logs: str, patterns: Sequence[str], candidate_index:
             )
 
 
+def _get_auto_conf_volume(check_root: str | os.PathLike[str] | None = None) -> str:
+    check_root = os.fspath(check_root or find_check_root(depth=2))
+    check_name = os.path.basename(check_root)
+    check_pkg = os.path.join(check_root, 'datadog_checks', check_name)
+    return f'{check_pkg}/data/auto_conf.yaml:/etc/datadog-agent/conf.d/{check_name}.d/auto_conf.yaml:ro'
+
+
 def get_e2e_discovery_metadata(
     check_root: str | os.PathLike[str] | None = None,
 ) -> dict[str, list[str]]:
@@ -240,19 +247,55 @@ def get_e2e_discovery_metadata(
     per-env config is temporarily replaced with an empty-instances file, leaving
     ``auto_conf.yaml`` as the sole AD template driving config-discovery.
     """
-    check_root = os.fspath(check_root or find_check_root(depth=1))
-    check_name = os.path.basename(check_root)
-    check_pkg = os.path.join(check_root, 'datadog_checks', check_name)
-    auto_conf = os.path.join(check_pkg, 'data', 'auto_conf.yaml')
-
     return {
         'docker_volumes': [
-            f'{auto_conf}:/etc/datadog-agent/conf.d/{check_name}.d/auto_conf.yaml:ro',
+            _get_auto_conf_volume(check_root),
             '/var/run/docker.sock:/var/run/docker.sock:ro',
         ],
     }
 
 
+def get_e2e_process_discovery_metadata(
+    check_root: str | os.PathLike[str] | None = None,
+) -> dict[str, list[str] | dict[str, str]]:
+    """Return metadata for an e2e process-autodiscovery run.
+
+    Mounts the integration's ``auto_conf.yaml`` into the agent container
+    (without the Docker socket) and sets ``DD_AUTOCONFIG_EXCLUDE_FEATURES=docker``
+    so only the process listener is active.
+
+    Use ``dd_agent_check_discovery`` alongside this metadata.
+    """
+    return {
+        'docker_volumes': [
+            _get_auto_conf_volume(check_root),
+        ],
+        'env_vars': {
+            # Reduce the default service collection interval from 60s to speed
+            # up tests.
+            'DD_DISCOVERY_SERVICE_COLLECTION_INTERVAL': '10s',
+            # Process autodiscovery will only match processes that are not
+            # inside a container. Since our test environment actually run the
+            # services inside containers, we need to exclude the docker
+            # features, so that the agent doesn't know about the containers.
+            'DD_AUTOCONFIG_EXCLUDE_FEATURES': 'docker',
+            # The agent container has /proc:/host/proc mounted by ddev. Without this,
+            # the workloadmeta process-collector scans /proc (the container's own PID
+            # namespace) instead of /host/proc, so host processes aren't visible.
+            #
+            # This is normally automatically detected by the agent when running
+            # inside a container, but it's not in this case since we
+            # explicitly disable the agent's docker-based features.
+            'DD_PROC_ROOT': '/host/proc',
+        },
+        # system-probe(-lite) needs these capabilities to read /proc entries of
+        # other processes for service discovery. Without them it falls back to
+        # only scanning the agent's own PID namespace, which finds no host
+        # processes.
+        'cap_add': ['SYS_PTRACE', 'DAC_READ_SEARCH'],
+    }
+
+
 def compose_file_active(compose_file):
     """
     Returns a `bool` indicating whether or not a compose file has any active services.

datadog_checks_dev/datadog_checks/dev/plugin/pytest.py

@@ -8,6 +8,7 @@
 import re
 from base64 import urlsafe_b64encode
 from collections import namedtuple  # Not using dataclasses for Py2 compatibility
+from collections.abc import Collection
 from io import open
 from typing import Dict, List, Literal, Optional, Tuple, overload  # noqa: F401
 
@@ -238,7 +239,7 @@ def run_check(config=None, **kwargs):
 
 
 @pytest.fixture
-def dd_agent_check_discovery(dd_agent_check):
+def dd_agent_check_discovery(dd_agent_check, is_process_e2e):
     """Wrapper around ``dd_agent_check`` for config-discovery e2e tests.
 
     Passes the empty-instances config required to let ``auto_conf.yaml`` drive
@@ -248,7 +249,13 @@ def dd_agent_check_discovery(dd_agent_check):
     if not e2e_testing():
         pytest.skip('Not running E2E tests')
 
-    def run(*, discovery_min_instances=1, discovery_timeout=30, **kwargs):
+    # Process autodiscovery needs to wait for the agent to recognize the process
+    # as a service which happens after a minimum process age of 1 minute. This
+    # time can be reduced significantly once agent-side support for reducing the
+    # minimum age via configuration is available.
+    extra_timeout = 60 if is_process_e2e else 0
+
+    def run(*, discovery_min_instances=1, discovery_timeout=30 + extra_timeout, **kwargs):
         return dd_agent_check(
             {'init_config': {}, 'instances': []},
             discovery_min_instances=discovery_min_instances,
@@ -483,12 +490,29 @@ def enum_object_items(data_source, machine_name, object_name, detail_level):
 )
 
 
+def _is_process_e2e_env() -> bool:
+    return os.getenv('DDEV_E2E_PROCESS_DISCOVERY', 'false') == 'true'
+
+
+def _should_skip_in_process_e2e(keywords: Collection[str]) -> bool:
+    """In the process-autodiscovery e2e env, only ``process_e2e`` tests run."""
+    return 'process_e2e' not in keywords
+
+
+@pytest.fixture(scope='session')
+def is_process_e2e() -> bool:
+    return _is_process_e2e_env()
+
+
 def pytest_configure(config):
     # pytest will emit warnings if these aren't registered ahead of time
     for ttype in TEST_TYPES:
         config.addinivalue_line('markers', '{}: {}'.format(ttype.name, ttype.description))
 
     config.addinivalue_line("markers", "latest_metrics: marker for verifying support of new metrics")
+    config.addinivalue_line(
+        "markers", "process_e2e: also run this e2e test in the process autodiscovery e2e environment"
+    )
 
 
 def pytest_addoption(parser):
@@ -498,16 +522,22 @@ def pytest_addoption(parser):
 def pytest_collection_modifyitems(config, items):
     # at test collection time, this function gets called by pytest, see:
     # https://docs.pytest.org/en/latest/example/simple.html#control-skipping-of-tests-according-to-command-line-option
-    # if the particular option is not present, it will skip all tests marked `latest_metrics`
-    if config.getoption("--run-latest-metrics"):
-        # --run-check-metrics given in cli: do not skip slow tests
-        return
+    skip_latest_metrics = (
+        None
+        if config.getoption("--run-latest-metrics")
+        else pytest.mark.skip(reason="need --run-latest-metrics option to run")
+    )
+    skip_non_process_e2e = (
+        pytest.mark.skip(reason="not a process autodiscovery e2e test") if _is_process_e2e_env() else None
+    )
 
-    skip_latest_metrics = pytest.mark.skip(reason="need --run-latest-metrics option to run")
     for item in items:
-        if "latest_metrics" in item.keywords:
+        if skip_latest_metrics and "latest_metrics" in item.keywords:
             item.add_marker(skip_latest_metrics)
 
+        if skip_non_process_e2e and _should_skip_in_process_e2e(item.keywords):
+            item.add_marker(skip_non_process_e2e)
+
         item_path = item.path
         if item_path is None:
             continue

datadog_checks_dev/datadog_checks/dev/tooling/templates/configuration/auto_conf/cel_selector.yaml

@@ -0,0 +1,4 @@
+- name: cel_selector
+  description: CEL selector for autodiscovery.
+  enabled: true
+  example: {}

ddev/changelog.d/24238.added

@@ -0,0 +1 @@
+Pass capabilities from e2e metadata `cap_add` to the Agent container via `docker --cap-add`.

ddev/src/ddev/e2e/agent/docker.py

@@ -275,6 +275,9 @@ def start(self, *, agent_build: str | None, local_packages: dict[Path, str], env
         for key, value in sorted(env_vars.items()):
             command.extend(['-e', f'{key}={value}'])
 
+        for cap in self.metadata.get('cap_add', []):
+            command.extend(['--cap-add', cap])
+
         # The docker `--add-host` command will reliably create entries in the `/etc/hosts` file,
         # otherwise, edits to that file will be overwritten on container restarts
         for host, ip in self.metadata.get('custom_hosts', []):

krakend/assets/configuration/spec.yaml

@@ -80,4 +80,9 @@ files:
     overrides:
       value.example:
       - krakend
+  - template: auto_conf/cel_selector
+    overrides:
+      cel_selector.example:
+        processes:
+          - "process.name == 'krakend'"
   - template: auto_conf/discovery

krakend/changelog.d/24238.added

@@ -0,0 +1 @@
+Add process autodiscovery support.

krakend/datadog_checks/krakend/data/auto_conf.yaml

@@ -6,6 +6,12 @@
 ad_identifiers:
   - krakend
 
+## CEL selector for autodiscovery.
+#
+cel_selector:
+  processes:
+  - process.name == 'krakend'
+
 ## Enables configuration discovery
 #
 discovery: {}