Validate metrics and health route paths at construction

lite_bootstrap/instruments/healthchecks_instrument.py

@@ -6,6 +6,8 @@
 
 import typing_extensions
 
+from lite_bootstrap.exceptions import ConfigurationError
+from lite_bootstrap.helpers.path import is_valid_path
 from lite_bootstrap.instruments.base import BaseConfig, BaseInstrument
 
 
@@ -27,6 +29,13 @@ class HealthChecksConfig(BaseConfig):
     health_checks_include_in_schema: bool = False
     health_checks_probes: Mapping[str, HealthProbe] = dataclasses.field(default_factory=dict)
 
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        path = self.health_checks_path
+        if path and path != "/" and not is_valid_path(path):
+            msg = f"Invalid health_checks_path: {path!r}"
+            raise ConfigurationError(msg)
+
     @property
     def health_check_data(self) -> HealthCheckTypedDict:
         return {
@@ -41,11 +50,11 @@ def health_check_data(self) -> HealthCheckTypedDict:
 
 @dataclasses.dataclass(kw_only=True, slots=True)
 class HealthChecksInstrument(BaseInstrument[HealthChecksConfigT]):
-    not_configured_reason = "health_checks_enabled is False"
+    not_configured_reason = "health_checks_enabled is False or health_checks_path is empty"
 
     @classmethod
     def is_configured(cls, bootstrap_config: "HealthChecksConfig") -> bool:
-        return bootstrap_config.health_checks_enabled
+        return bootstrap_config.health_checks_enabled and bool(bootstrap_config.health_checks_path)
 
     def render_health_check_data(self, *, health_status: bool = True) -> HealthCheckTypedDict:
         health_check_data = self.bootstrap_config.health_check_data

lite_bootstrap/instruments/prometheus_instrument.py

@@ -3,6 +3,7 @@
 import dataclasses
 import typing
 
+from lite_bootstrap.exceptions import ConfigurationError
 from lite_bootstrap.helpers.path import is_valid_path
 from lite_bootstrap.instruments.base import BaseConfig, BaseInstrument
 
@@ -12,6 +13,13 @@ class PrometheusConfig(BaseConfig):
     prometheus_metrics_path: str = "/metrics"
     prometheus_metrics_include_in_schema: bool = False
 
+    def __post_init__(self) -> None:
+        super().__post_init__()
+        path = self.prometheus_metrics_path
+        if path and not is_valid_path(path):
+            msg = f"Invalid prometheus_metrics_path: {path!r}"
+            raise ConfigurationError(msg)
+
 
 @dataclasses.dataclass(kw_only=True, frozen=True)
 class PrometheusHttpConfig(PrometheusConfig):
@@ -29,10 +37,8 @@ def is_prometheus_http_metrics_on(self, *, opentelemetry_records_http_metrics: b
 
 @dataclasses.dataclass(kw_only=True, slots=True)
 class PrometheusInstrument(BaseInstrument[PrometheusConfigT]):
-    not_configured_reason = "prometheus_metrics_path is empty or not valid"
+    not_configured_reason = "prometheus_metrics_path is empty"
 
     @classmethod
     def is_configured(cls, bootstrap_config: "PrometheusConfig") -> bool:
-        return bool(bootstrap_config.prometheus_metrics_path) and is_valid_path(
-            bootstrap_config.prometheus_metrics_path
-        )
+        return bool(bootstrap_config.prometheus_metrics_path)

tests/instruments/test_healthchecks_instrument.py

@@ -16,7 +16,9 @@ def test_healthchecks_instrument_configured_by_default() -> None:
 def test_healthchecks_instrument_not_configured_when_disabled() -> None:
     config = HealthChecksConfig(health_checks_enabled=False)
     assert not HealthChecksInstrument.is_configured(config)
-    assert HealthChecksInstrument.not_configured_reason == "health_checks_enabled is False"
+    assert (
+        HealthChecksInstrument.not_configured_reason == "health_checks_enabled is False or health_checks_path is empty"
+    )
 
 
 def test_healthchecks_render_data_default() -> None:

tests/instruments/test_prometheus_instrument.py

@@ -9,13 +9,7 @@ def test_prometheus_instrument_configured_with_default_path() -> None:
 def test_prometheus_instrument_not_configured_with_empty_path() -> None:
     config = PrometheusConfig(prometheus_metrics_path="")
     assert not PrometheusInstrument.is_configured(config)
-    assert PrometheusInstrument.not_configured_reason == "prometheus_metrics_path is empty or not valid"
-
-
-def test_prometheus_instrument_not_configured_with_invalid_path() -> None:
-    # No leading slash → invalid per is_valid_path regex.
-    config = PrometheusConfig(prometheus_metrics_path="metrics")
-    assert not PrometheusInstrument.is_configured(config)
+    assert PrometheusInstrument.not_configured_reason == "prometheus_metrics_path is empty"
 
 
 def test_prometheus_instrument_configured_with_custom_valid_path() -> None:

tests/test_config.py

@@ -4,6 +4,7 @@
 import pytest
 
 from lite_bootstrap import FastAPIConfig, FastStreamConfig, FreeConfig, LitestarConfig
+from lite_bootstrap.exceptions import ConfigurationError
 from lite_bootstrap.instruments.base import BaseConfig
 from tests.conftest import CustomInstrumentor
 
@@ -119,3 +120,13 @@ def test_service_name_and_version_fall_back_for_readers_that_need_a_string(
 ) -> None:
     assert config.service_name_or_default == expected_name
     assert config.service_version_or_default == expected_version
+
+
+def test_invalid_prometheus_metrics_path_raises_at_construction() -> None:
+    with pytest.raises(ConfigurationError, match="prometheus_metrics_path"):
+        FastAPIConfig(prometheus_metrics_path="metrics")
+
+
+def test_invalid_health_checks_path_raises_at_construction() -> None:
+    with pytest.raises(ConfigurationError, match="health_checks_path"):
+        FastAPIConfig(health_checks_path="health")

tests/test_fastapi_bootstrap.py

@@ -740,3 +740,11 @@ def test_built_app_title_and_version_fall_back_when_unset() -> None:
     application = FastAPIConfig().app
     assert application.title == "micro-service"
     assert application.version == "1.0.0"
+
+
+def test_empty_observability_paths_disable_routes() -> None:
+    config = FastAPIConfig(health_checks_path="", prometheus_metrics_path="")
+    with _bootstrapped(config) as application, TestClient(application) as client:
+        assert client.get("/health/").status_code == status.HTTP_404_NOT_FOUND
+        assert client.get("/metrics").status_code == status.HTTP_404_NOT_FOUND
+        assert client.get("/").status_code == status.HTTP_404_NOT_FOUND

tests/test_faststream_bootstrap.py

@@ -460,7 +460,7 @@ def test_faststream_prometheus_is_skipped_without_metrics_path(broker: RedisBrok
     )
     bootstrapper = FastStreamBootstrapper(bootstrap_config=bootstrap_config)
     skipped = dict(bootstrapper.skipped_instruments)
-    assert skipped[FastStreamPrometheusInstrument] == "prometheus_metrics_path is empty or not valid"
+    assert skipped[FastStreamPrometheusInstrument] == "prometheus_metrics_path is empty"
 
 
 async def test_faststream_prometheus_serves_the_default_registry(broker: RedisBroker) -> None: