feat: add healthz endpoints

closes #27

Author: alukach

src/stac_auth_proxy/app.py

@@ -11,7 +11,7 @@
 from fastapi import FastAPI
 
 from .config import Settings
-from .handlers import ReverseProxyHandler
+from .handlers import HealthzHandler, ReverseProxyHandler
 from .middleware import (
     AddProcessTimeHeaderMiddleware,
     ApplyCql2FilterMiddleware,
@@ -58,12 +58,9 @@ def create_app(settings: Optional[Settings] = None) -> FastAPI:
         oidc_config_url=settings.oidc_discovery_url,
     )
 
-    if settings.debug:
-        app.add_api_route(
-            "/_debug",
-            lambda: {"settings": settings},
-            methods=["GET"],
-        )
+    if settings.healthz_prefix:
+        healthz_handler = HealthzHandler(upstream_url=str(settings.upstream_url))
+        app.include_router(healthz_handler.router, prefix="/healthz")
 
     # Catchall for any endpoint
     proxy_handler = ReverseProxyHandler(upstream=str(settings.upstream_url))

src/stac_auth_proxy/config.py

@@ -8,6 +8,7 @@
 from pydantic_settings import BaseSettings, SettingsConfigDict
 
 EndpointMethods: TypeAlias = dict[str, list[str]]
+_PREFIX_PATTERN = r"^/.*$"
 
 
 class ClassInput(BaseModel):
@@ -28,12 +29,11 @@ def __call__(self):
 class Settings(BaseSettings):
     """Configuration settings for the STAC Auth Proxy."""
 
-    debug: bool = False
-
     upstream_url: HttpUrl = HttpUrl(url="https://earth-search.aws.element84.com/v1")
     oidc_discovery_url: HttpUrl
 
     # Endpoints
+    healthz_prefix: str = Field(pattern=_PREFIX_PATTERN, default="/healthz")
     default_public: bool = False
     private_endpoints: EndpointMethods = {
         # https://github.com/stac-api-extensions/collection-transaction/blob/v1.0.0-beta.1/README.md#methods

src/stac_auth_proxy/handlers/__init__.py

@@ -1,5 +1,6 @@
 """Handlers to process requests."""
 
+from .healthz import HealthzHandler
 from .reverse_proxy import ReverseProxyHandler
 
-__all__ = ["ReverseProxyHandler"]
+__all__ = ["ReverseProxyHandler", "HealthzHandler"]

src/stac_auth_proxy/handlers/healthz.py

@@ -0,0 +1,31 @@
+"""Health check endpoints."""
+
+from dataclasses import dataclass, field
+
+from fastapi import APIRouter
+from httpx import AsyncClient
+
+
+@dataclass
+class HealthzHandler:
+    """Handler for health check endpoints."""
+
+    upstream_url: str
+    router: APIRouter = field(init=False)
+
+    def __post_init__(self):
+        """Initialize the router."""
+        self.router = APIRouter()
+        self.router.add_api_route("/", self.healthz, methods=["GET"])
+        self.router.add_api_route("/upstream", self.healthz_upstream, methods=["GET"])
+
+    async def healthz(self):
+        """Return health of this API."""
+        return {"status": "ok"}
+
+    async def healthz_upstream(self):
+        """Return health of upstream STAC API."""
+        async with AsyncClient() as client:
+            response = await client.get(self.upstream_url)
+            response.raise_for_status()
+            return {"status": "ok", "code": response.status_code}