From 71338d623fdccd263630d5142ba9f458c279ad40 Mon Sep 17 00:00:00 2001
From: Alexander Tarasov <alex.tarasov@sentry.io>
Date: Thu, 8 Oct 2026 17:43:15 +0200
Subject: [PATCH] feat(client): Add healthcheck command for the worker liveness
 probe

Add `python3 -m taskbroker_client.healthcheck <path>`, which removes the
health file the worker touches, or exits 1 with a one-line message if
it is missing. Pods currently run `rm <path>`, which does not work on
distroless images that have no shell or rm.

The worker writes the file, so the client should own the check. The
path is required because neither the client nor sentry has a default;
ops passes it per pool.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---
 .../src/taskbroker_client/healthcheck.py      | 28 +++++++++++++++++++
 clients/python/tests/test_healthcheck.py      | 19 +++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 clients/python/src/taskbroker_client/healthcheck.py
 create mode 100644 clients/python/tests/test_healthcheck.py

diff --git a/clients/python/src/taskbroker_client/healthcheck.py b/clients/python/src/taskbroker_client/healthcheck.py
new file mode 100644
index 00000000..5465b559
--- /dev/null
+++ b/clients/python/src/taskbroker_client/healthcheck.py
@@ -0,0 +1,28 @@
+import argparse
+import os
+import sys
+
+
+def healthcheck(path: str) -> None:
+    """
+    Remove the health file, so the next check fails unless the worker touches it
+    again. Runs as the worker pod's liveness probe.
+    """
+    try:
+        os.remove(path)
+    except FileNotFoundError:
+        sys.exit(f"{path} is missing: the worker has not touched it since the last probe")
+
+
+def main(argv: list[str] | None = None) -> None:
+    parser = argparse.ArgumentParser(
+        prog="python3 -m taskbroker_client.healthcheck",
+        description="Remove the worker health file, or exit 1 if it is missing.",
+    )
+    parser.add_argument("path", help="the health check file the worker touches")
+    args = parser.parse_args(argv)
+    healthcheck(args.path)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/clients/python/tests/test_healthcheck.py b/clients/python/tests/test_healthcheck.py
new file mode 100644
index 00000000..816b5518
--- /dev/null
+++ b/clients/python/tests/test_healthcheck.py
@@ -0,0 +1,19 @@
+from pathlib import Path
+
+import pytest
+
+from taskbroker_client.healthcheck import main
+
+
+def test_fails_when_worker_has_not_touched_file_since_last_check(tmp_path: Path) -> None:
+    path = tmp_path / "health"
+    path.touch()
+
+    main([str(path)])
+    assert not path.exists()
+
+    with pytest.raises(SystemExit) as exc:
+        main([str(path)])
+    assert exc.value.code == (
+        f"{path} is missing: the worker has not touched it since the last probe"
+    )