chore(rc): add process tags (#15298)

This PR implements this
[RFC](https://docs.google.com/document/d/1AFdLUuVk70i0bJd5335-RxqsvwAV9ovAqcO2z5mEMbA/edit?pli=1&tab=t.0#heading=h.s9l1lctqlg11)
for remote.

Add process_tags to remote config payload. Note that remote config needs
an array and not a string of value. We also retest that the right values
are set.

## Testing

- Check that process tags are not included if deactivated
- Check the process tags are set in the payload when activated.

Author: dubloom

ddtrace/internal/process_tags/__init__.py

@@ -2,7 +2,9 @@
 from pathlib import Path
 import re
 import sys
+from typing import List
 from typing import Optional
+from typing import Tuple
 
 from ddtrace.internal.logger import get_logger
 from ddtrace.internal.settings.process_tags import process_tags_config as config
@@ -44,12 +46,12 @@ def is_allowed_char(char: str) -> str:
     return result.strip("_")
 
 
-def generate_process_tags() -> Optional[str]:
+def generate_process_tags() -> Tuple[Optional[str], Optional[List[str]]]:
     if not config.enabled:
-        return None
+        return None, None
 
     try:
-        return ",".join(
+        process_tags_list = [
             f"{key}:{normalize_tag_value(value)}"
             for key, value in sorted(
                 [
@@ -59,10 +61,12 @@ def generate_process_tags() -> Optional[str]:
                     (ENTRYPOINT_TYPE_TAG, ENTRYPOINT_TYPE_SCRIPT),
                 ]
             )
-        )
+        ]
+        process_tags = ",".join(process_tags_list)
+        return process_tags, process_tags_list
     except Exception as e:
         log.debug("failed to get process_tags: %s", e)
-        return None
+        return None, None
 
 
-process_tags = generate_process_tags()
+process_tags, process_tags_list = generate_process_tags()

ddtrace/internal/remoteconfig/client.py

@@ -21,6 +21,7 @@
 import ddtrace
 from ddtrace.internal import agent
 from ddtrace.internal import gitmetadata
+from ddtrace.internal import process_tags
 from ddtrace.internal import runtime
 from ddtrace.internal.hostname import get_hostname
 from ddtrace.internal.logger import get_logger
@@ -233,6 +234,10 @@ def __init__(self) -> None:
             app_version=ddtrace.config.version,
             tags=[":".join(_) for _ in tags.items()],
         )
+
+        if p_tags_list := process_tags.process_tags_list:
+            self._client_tracer["process_tags"] = p_tags_list
+
         self.cached_target_files: List[AppliedConfigType] = []
 
         self._products: MutableMapping[str, PubSub] = dict()

tests/internal/remoteconfig/test_remoteconfig.py

@@ -802,3 +802,44 @@ def test_apm_tracing_sampling_rules_none_override(remote_config_worker):
         # Restore original config
         config.service = original_service
         config.env = original_env
+
+
+def test_remote_config_payload_not_includes_process_tags():
+    client = RemoteConfigClient()
+    payload = client._build_payload({})
+
+    assert "process_tags" not in payload["client"]["client_tracer"]
+
+
+@pytest.mark.subprocess(env={"DD_EXPERIMENTAL_PROPAGATE_PROCESS_TAGS_ENABLED": "True"})
+def test_remote_config_payload_includes_process_tags():
+    import os
+    import sys
+    from unittest.mock import patch
+
+    from ddtrace.internal.process_tags import ENTRYPOINT_BASEDIR_TAG
+    from ddtrace.internal.process_tags import ENTRYPOINT_NAME_TAG
+    from ddtrace.internal.process_tags import ENTRYPOINT_TYPE_SCRIPT
+    from ddtrace.internal.process_tags import ENTRYPOINT_TYPE_TAG
+    from ddtrace.internal.process_tags import ENTRYPOINT_WORKDIR_TAG
+    from ddtrace.internal.remoteconfig.client import RemoteConfigClient
+    from tests.utils import process_tag_reload
+
+    with (
+        patch.object(sys, "argv", ["/path/to/test_script.py"]),
+        patch.object(os, "getcwd", return_value="/path/to/workdir"),
+    ):
+        process_tag_reload()
+
+        client = RemoteConfigClient()
+        payload = client._build_payload({})
+
+        assert "process_tags" in payload["client"]["client_tracer"]
+
+        process_tags = payload["client"]["client_tracer"]["process_tags"]
+
+        assert isinstance(process_tags, list)
+        assert f"{ENTRYPOINT_BASEDIR_TAG}:to" in process_tags
+        assert f"{ENTRYPOINT_NAME_TAG}:test_script" in process_tags
+        assert f"{ENTRYPOINT_TYPE_TAG}:{ENTRYPOINT_TYPE_SCRIPT}" in process_tags
+        assert f"{ENTRYPOINT_WORKDIR_TAG}:workdir" in process_tags

tests/internal/test_process_tags.py

@@ -81,10 +81,12 @@ def setUp(self):
         super(TestProcessTags, self).setUp()
         self._original_process_tags_enabled = config.enabled
         self._original_process_tags = process_tags.process_tags
+        self._original_process_tags_list = process_tags.process_tags_list
 
     def tearDown(self):
         config.enabled = self._original_process_tags_enabled
         process_tags.process_tags = self._original_process_tags
+        process_tags.process_tags_list = self._original_process_tags_list
         super().tearDown()
 
     @pytest.mark.snapshot

tests/utils.py

@@ -1623,4 +1623,4 @@ def override_third_party_packages(packages: List[str]):
 
 
 def process_tag_reload():
-    process_tags.process_tags = process_tags.generate_process_tags()
+    process_tags.process_tags, process_tags.process_tags_list = process_tags.generate_process_tags()