feat: add health monitoring endpoint

apps/health/tests/__init__.py

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+

apps/health/tests/test_checks.py

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+from __future__ import annotations
+
+import importlib
+import time
+from types import SimpleNamespace
+
+import pytest
+from django.db.utils import OperationalError
+
+from apps.health import checks
+
+
+class SuccessfulCursor:
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc, tb):
+        return False
+
+    def execute(self, query):
+        self.query = query
+
+
+class FailingCursor:
+    def __enter__(self):
+        return self
+
+    def __exit__(self, exc_type, exc, tb):
+        return False
+
+    def execute(self, query):
+        raise OperationalError("database unavailable")
+
+
+class FakeCache:
+    def __init__(self, value_to_return=None):
+        self.value_to_return = value_to_return
+        self.stored = {}
+
+    def set(self, key, value, timeout=None):
+        self.stored[key] = value
+
+    def get(self, key):
+        if self.value_to_return is not None:
+            return self.value_to_return
+        return self.stored.get(key)
+
+    def delete(self, key):
+        self.stored.pop(key, None)
+
+
+@pytest.mark.django_db
+def test_db_ok(monkeypatch):
+    monkeypatch.setattr(checks.connection, "cursor", lambda: SuccessfulCursor())
+
+    result = checks.check_db()
+
+    assert result["status"] == "ok"
+    assert "latency_ms" in result
+
+
+@pytest.mark.django_db
+def test_db_fail(monkeypatch):
+    monkeypatch.setattr(checks.connection, "cursor", lambda: FailingCursor())
+
+    result = checks.check_db()
+
+    assert result == {"status": "fail", "detail": "database unavailable"}
+
+
+@pytest.mark.django_db
+def test_cache_ok(monkeypatch):
+    monkeypatch.setattr(checks, "cache", FakeCache())
+
+    result = checks.check_cache()
+
+    assert result["status"] == "ok"
+    assert "latency_ms" in result
+
+
+@pytest.mark.django_db
+def test_cache_fail(monkeypatch):
+    monkeypatch.setattr(checks, "cache", FakeCache(value_to_return="wrong-value"))
+
+    result = checks.check_cache()
+
+    assert result == {"status": "fail", "detail": "Cache probe returned unexpected value"}
+
+
+def test_celery_no_broker(monkeypatch):
+    monkeypatch.delenv("CELERY_BROKER_URL", raising=False)
+
+    result = checks.check_celery()
+
+    assert result["status"] == "ok"
+    assert "CELERY_BROKER_URL is unset" in result["detail"]
+
+
+def test_celery_no_kombu(monkeypatch):
+    monkeypatch.setenv("CELERY_BROKER_URL", "redis://broker")
+
+    def raise_import_error(name):
+        raise ImportError(name)
+
+    monkeypatch.setattr(importlib, "import_module", raise_import_error)
+
+    result = checks.check_celery()
+
+    assert result["status"] == "ok"
+    assert "kombu is not installed" in result["detail"]
+
+
+def test_celery_ok(monkeypatch):
+    monkeypatch.setenv("CELERY_BROKER_URL", "redis://broker")
+
+    class FakeBrokerConnection:
+        def __init__(self, url, connect_timeout):
+            self.url = url
+            self.connect_timeout = connect_timeout
+
+        def __enter__(self):
+            return self
+
+        def __exit__(self, exc_type, exc, tb):
+            return False
+
+        def ensure_connection(self, max_retries):
+            self.max_retries = max_retries
+
+    monkeypatch.setattr(importlib, "import_module", lambda name: SimpleNamespace(Connection=FakeBrokerConnection))
+
+    result = checks.check_celery()
+
+    assert result == {"status": "ok"}
+
+
+def test_celery_fail(monkeypatch):
+    monkeypatch.setenv("CELERY_BROKER_URL", "redis://broker")
+
+    class BrokenBrokerConnection:
+        def __init__(self, url, connect_timeout):
+            self.url = url
+            self.connect_timeout = connect_timeout
+
+        def __enter__(self):
+            raise OSError("broker down")
+
+        def __exit__(self, exc_type, exc, tb):
+            return False
+
+    monkeypatch.setattr(importlib, "import_module", lambda name: SimpleNamespace(Connection=BrokenBrokerConnection))
+
+    result = checks.check_celery()
+
+    assert result == {"status": "fail", "detail": "broker down"}
+
+
+def test_backup_no_env(monkeypatch):
+    monkeypatch.delenv("BACKUP_STATUS_FILE", raising=False)
+
+    result = checks.check_backup()
+
+    assert result["status"] == "fail"
+    assert "BACKUP_STATUS_FILE is unset" in result["detail"]
+
+
+def test_backup_missing_file(monkeypatch, tmp_path):
+    status_file = tmp_path / "missing-backup-status"
+    monkeypatch.setenv("BACKUP_STATUS_FILE", str(status_file))
+
+    result = checks.check_backup()
+
+    assert result == {"status": "fail", "detail": f"Backup status file not found: {status_file}"}
+
+
+def test_backup_fresh(monkeypatch, tmp_path):
+    status_file = tmp_path / "backup-status"
+    status_file.write_text(str(time.time() - 60), encoding="utf-8")
+    monkeypatch.setenv("BACKUP_STATUS_FILE", str(status_file))
+
+    result = checks.check_backup()
+
+    assert result == {"status": "ok"}
+
+
+def test_backup_stale(monkeypatch, tmp_path):
+    status_file = tmp_path / "backup-status"
+    stale_timestamp = time.time() - (checks.BACKUP_MAX_AGE_SECONDS + 1)
+    status_file.write_text(str(stale_timestamp), encoding="utf-8")
+    monkeypatch.setenv("BACKUP_STATUS_FILE", str(status_file))
+
+    result = checks.check_backup()
+
+    assert result["status"] == "fail"
+    assert "Last backup is" in result["detail"]
+
+
+def test_backup_invalid(monkeypatch, tmp_path):
+    status_file = tmp_path / "backup-status"
+    status_file.write_text("not-a-timestamp", encoding="utf-8")
+    monkeypatch.setenv("BACKUP_STATUS_FILE", str(status_file))
+
+    result = checks.check_backup()
+
+    assert result == {"status": "fail", "detail": "Invalid backup status file"}

apps/health/tests/test_views.py

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+from __future__ import annotations
+
+import re
+
+import pytest
+
+
+def _mock_checks(monkeypatch, **overrides):
+    payloads = {
+        "db": {"status": "ok", "latency_ms": 1.0},
+        "cache": {"status": "ok", "latency_ms": 1.0},
+        "celery": {"status": "ok"},
+        "backup": {"status": "ok"},
+    }
+    payloads.update(overrides)
+
+    monkeypatch.setattr("apps.health.views.check_db", lambda: payloads["db"])
+    monkeypatch.setattr("apps.health.views.check_cache", lambda: payloads["cache"])
+    monkeypatch.setattr("apps.health.views.check_celery", lambda: payloads["celery"])
+    monkeypatch.setattr("apps.health.views.check_backup", lambda: payloads["backup"])
+
+
+@pytest.mark.django_db
+def test_healthy(client, monkeypatch):
+    _mock_checks(monkeypatch)
+
+    response = client.get("/health/")
+
+    assert response.status_code == 200
+    assert response.json()["status"] == "ok"
+
+
+@pytest.mark.django_db
+def test_degraded_celery(client, monkeypatch):
+    _mock_checks(monkeypatch, celery={"status": "fail", "detail": "broker down"})
+
+    response = client.get("/health/")
+
+    assert response.status_code == 200
+    assert response.json()["status"] == "degraded"
+
+
+@pytest.mark.django_db
+def test_degraded_backup(client, monkeypatch):
+    _mock_checks(monkeypatch, backup={"status": "fail", "detail": "backup missing"})
+
+    response = client.get("/health/")
+
+    assert response.status_code == 200
+    assert response.json()["status"] == "degraded"
+
+
+@pytest.mark.django_db
+def test_unhealthy_db(client, monkeypatch):
+    _mock_checks(monkeypatch, db={"status": "fail", "detail": "db down"})
+
+    response = client.get("/health/")
+
+    assert response.status_code == 503
+    assert response.json()["status"] == "unhealthy"
+
+
+@pytest.mark.django_db
+def test_unhealthy_cache(client, monkeypatch):
+    _mock_checks(monkeypatch, cache={"status": "fail", "detail": "cache down"})
+
+    response = client.get("/health/")
+
+    assert response.status_code == 503
+    assert response.json()["status"] == "unhealthy"
+
+
+@pytest.mark.django_db
+def test_response_shape(client, monkeypatch):
+    _mock_checks(monkeypatch)
+
+    payload = client.get("/health/").json()
+
+    assert set(payload) == {"status", "version", "checks", "timestamp"}
+    assert set(payload["version"]) == {"git_sha", "build"}
+    assert set(payload["checks"]) == {"db", "cache", "celery", "backup"}
+    assert re.fullmatch(r"\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}Z", payload["timestamp"])
+
+
+@pytest.mark.django_db
+def test_version_fields(client, monkeypatch):
+    _mock_checks(monkeypatch)
+    monkeypatch.setenv("GIT_SHA", "59cc1c4")
+    monkeypatch.setenv("BUILD_ID", "build-20260306-59cc1c4")
+
+    payload = client.get("/health/").json()
+
+    assert payload["version"]["git_sha"]
+    assert payload["version"]["build"]
+
+
+@pytest.mark.django_db
+def test_no_cache_headers(client, monkeypatch):
+    _mock_checks(monkeypatch)
+
+    response = client.get("/health/")
+
+    assert "no-cache" in response["Cache-Control"]