Merge pull request #68 from statisticsnorway/fastapi

Fastapi

Author: DanielElisenberg

Dockerfile

@@ -53,4 +53,4 @@ ENV PYTHONPATH "${PYTHONPATH}:/app:/app/dependencies"
 # Change user
 USER microdata
 
-CMD ["/app/dependencies/bin/gunicorn", "--logger-class", "metadata_service.config.gunicorn.CustomLogger", "metadata_service.app:app", "--workers", "2", "--limit-request-line", "8190"]
+CMD ["/app/dependencies/bin/gunicorn", "-k", "uvicorn.workers.UvicornWorker", "--logger-class", "metadata_service.config.gunicorn.CustomLogger", "metadata_service.app:app", "--workers", "2", "--limit-request-line", "8190"]

metadata_service/adapter/datastore.py

@@ -25,7 +25,7 @@ def get_datastore_versions() -> dict:
         return json.load(f)
 
 
-def _get_draft_metadata_all():
+def _get_draft_metadata_all() -> dict:
     metadata_all_file_path = (
         f"{DATASTORE_ROOT_DIR}/datastore/metadata_all__DRAFT.json"
     )
@@ -34,7 +34,7 @@ def _get_draft_metadata_all():
 
 
 @lru_cache(maxsize=32)
-def _get_versioned_metadata_all(version: Version):
+def _get_versioned_metadata_all(version: Version) -> dict:
     file_version = version.to_3_underscored()
     metadata_all_file_path = (
         f"{DATASTORE_ROOT_DIR}/datastore/metadata_all__{file_version}.json"
@@ -43,7 +43,7 @@ def _get_versioned_metadata_all(version: Version):
         return json.load(f)
 
 
-def get_metadata_all(version: Version) -> str:
+def get_metadata_all(version: Version) -> dict:
     try:
         if version.is_draft():
             return _get_draft_metadata_all()

metadata_service/api/metadata_api.py

@@ -1,100 +1,73 @@
 import logging
 
-from flask import Blueprint, jsonify, request
+from fastapi import APIRouter, Depends
 
 from metadata_service.api.request_models import NameParam, MetadataQuery
 from metadata_service.domain import metadata
 from metadata_service.domain.version import get_version_from_string
 
 logger = logging.getLogger()
-metadata_api = Blueprint("metadata_api", __name__)
+metadata_router = APIRouter()
 
 
-@metadata_api.get("/metadata/data-store")
+@metadata_router.get("/metadata/data-store")
 def get_data_store():
     logger.info("GET /metadata/data-store")
+    return metadata.find_all_datastore_versions()
 
-    response = jsonify(metadata.find_all_datastore_versions())
-    response.headers.set("content-language", "no")
-    return response
 
-
-@metadata_api.get("/metadata/data-structures/status")
-def get_data_structure_current_status():
-    validated_query = NameParam(**request.args)
+@metadata_router.get("/metadata/data-structures/status")
+def get_data_structure_current_status(validated_query: NameParam = Depends()):
     logger.info(
         f"GET /metadata/data-structures/status with name = {validated_query.names}"
     )
-    response = jsonify(
-        metadata.find_current_data_structure_status(
-            validated_query.get_names_as_list()
-        )
+    return metadata.find_current_data_structure_status(
+        validated_query.get_names_as_list()
     )
-    response.headers.set("content-language", "no")
-    return response
-
 
-@metadata_api.post("/metadata/data-structures/status")
-def get_data_structure_current_status_as_post():
-    validated_body = NameParam(**request.json)
 
+@metadata_router.post("/metadata/data-structures/status")
+def get_data_structure_current_status_as_post(validated_body: NameParam):
     logger.info(
         f"POST /metadata/data-structures/status with name = {validated_body.names}"
     )
-    response = jsonify(
-        metadata.find_current_data_structure_status(
-            validated_body.get_names_as_list()
-        )
+    return metadata.find_current_data_structure_status(
+        validated_body.get_names_as_list()
     )
-    response.headers.set("content-language", "no")
-    return response
 
 
-@metadata_api.get("/metadata/data-structures")
-def get_data_structures():
-    validated_query = MetadataQuery(**request.args)
+@metadata_router.get("/metadata/data-structures")
+def get_data_structures(
+    validated_query: MetadataQuery = Depends(),
+):
     validated_query.include_attributes = True
     logger.info(f"GET /metadata/data-structures with query: {validated_query}")
-
-    response = jsonify(
-        metadata.find_data_structures(
-            validated_query.names,
-            get_version_from_string(validated_query.version),
-            validated_query.include_attributes,
-            validated_query.skip_code_lists,
-        )
+    return metadata.find_data_structures(
+        validated_query.names_as_list(),
+        get_version_from_string(validated_query.version),
+        validated_query.include_attributes,
+        validated_query.skip_code_lists,
     )
-    response.headers.set("content-language", "no")
-    return response
 
 
-@metadata_api.get("/metadata/all-data-structures")
+@metadata_router.get("/metadata/all-data-structures")
 def get_all_data_structures_ever():
     logger.info("GET /metadata/all-data-structures")
+    return metadata.find_all_data_structures_ever()
 
-    response = jsonify(metadata.find_all_data_structures_ever())
-    response.headers.set("content-language", "no")
-    return response
 
-
-@metadata_api.get("/metadata/all")
-def get_all_metadata():
-    validated_query = MetadataQuery(**request.args)
+@metadata_router.get("/metadata/all")
+def get_all_metadata(
+    validated_query: MetadataQuery = Depends(),
+):
     logger.info(f"GET /metadata/all with version: {validated_query.version}")
-
-    response = jsonify(
-        metadata.find_all_metadata(
-            get_version_from_string(validated_query.version),
-            validated_query.skip_code_lists,
-        )
+    return metadata.find_all_metadata(
+        get_version_from_string(validated_query.version),
+        validated_query.skip_code_lists,
     )
-    response.headers.set("content-language", "no")
-    return response
 
 
-@metadata_api.get("/languages")
+@metadata_router.get("/languages")
 def get_languages():
     logger.info("GET /languages")
-
-    response = jsonify(metadata.find_languages())
-    return response
+    return metadata.find_languages()

metadata_service/api/observability.py

@@ -1,14 +1,14 @@
-from flask import Blueprint
+from fastapi import APIRouter
 
 
-observability = Blueprint("observability", __name__)
+observability_router = APIRouter()
 
 
-@observability.get("/health/alive")
-def alive():
+@observability_router.get("/health/alive")
+async def alive():
     return "I'm alive!"
 
 
-@observability.get("/health/ready")
-def ready():
+@observability_router.get("/health/ready")
+async def ready():
     return "I'm ready!"

metadata_service/api/request_models.py

@@ -11,23 +11,11 @@
 
 
 class MetadataQuery(BaseModel, extra="forbid", validate_assignment=True):
-    names: List[str] = []
+    names: str | None = None
     version: str
     include_attributes: bool = False
     skip_code_lists: bool = False
 
-    @field_validator("names", mode="before")
-    @classmethod
-    def split_str(cls, names):
-        if isinstance(names, List):
-            return names[0].split(",")
-        elif isinstance(names, str):
-            return names.split(",")
-        else:
-            raise RequestValidationException(
-                "names field must be a list or a string"
-            )
-
     @field_validator("version", mode="before")
     @classmethod
     def validate_version(cls, version: str):
@@ -38,6 +26,9 @@ def validate_version(cls, version: str):
             )
         return version
 
+    def names_as_list(self) -> List[str]:
+        return [] if self.names is None else self.names.split(",")
+
 
 class NameParam(BaseModel, extra="forbid"):
     names: str

metadata_service/app.py

@@ -1,12 +1,12 @@
 import logging
 
-import msgpack
-from flask import Flask, Response, request, jsonify, make_response
-from werkzeug.exceptions import NotFound, BadHost
-
-from metadata_service.api.metadata_api import metadata_api
-from metadata_service.api.observability import observability
+from fastapi.responses import JSONResponse
+from fastapi import FastAPI
+from starlette.exceptions import HTTPException
+from metadata_service.api.metadata_api import metadata_router
+from metadata_service.api.observability import observability_router
 from metadata_service.config.logging import setup_logging
+from metadata_service.config.uvicorn import setup_uvicorn_logging
 from metadata_service.exceptions.exceptions import (
     DataNotFoundException,
     InvalidStorageFormatException,
@@ -17,99 +17,83 @@
 
 logger = logging.getLogger()
 
-app = Flask(__name__)
-app.register_blueprint(observability)
-app.register_blueprint(metadata_api)
+app = FastAPI()
+app.include_router(observability_router)
+app.include_router(metadata_router)
 
 setup_logging(app)
+setup_uvicorn_logging()
 
 
-@app.after_request
-def after_request(response: Response):
-    if (
-        "Accept" in request.headers
-        and request.headers["Accept"] == "application/x-msgpack"
-    ):
-        # create a new Response to send the payload only as "data" field
-        response_msgpack = make_response(msgpack.dumps(response.json))
-        response_msgpack.headers.set("Content-Type", "application/x-msgpack")
-        return response_msgpack
-
+@app.middleware("http")
+async def add_language_header(request, call_next):
+    response = await call_next(request)
+    response.headers.setdefault("Content-Language", "no")
     return response
 
 
-@app.errorhandler(Exception)
-def handle_generic_exception(exc):
-    logger.exception(exc)
-    return (
-        jsonify(
-            {
-                "code": 202,
-                "message": f"Error: {str(exc)}",
-                "service": "metadata-service",
-                "type": "SYSTEM_ERROR",
-            }
-        ),
-        500,
-    )
-
-
-@app.errorhandler(NotFound)
-def handle_url_invalid(exc):
-    logger.warning(exc, exc_info=True)
-    return (
-        jsonify(
-            {
+@app.exception_handler(HTTPException)
+async def custom_http_exception_handler(_req, exc):
+    if exc.status_code == 404:
+        return JSONResponse(
+            content={
                 "code": 103,
                 "message": f"Error: {str(exc)}",
                 "service": "metadata-service",
                 "type": "PATH_NOT_FOUND",
-            }
-        ),
-        400,
+            },
+            status_code=400,
+        )
+    return JSONResponse(
+        content={
+            "code": 202,
+            "message": f"Error: {str(exc)}",
+            "service": "metadata-service",
+            "type": "SYSTEM_ERROR",
+        },
+        status_code=500,
     )
 
 
-@app.errorhandler(BadHost)
-def handle_bad_host(exc):
-    logger.warning(exc, exc_info=True)
-    return (
-        jsonify(
-            {
-                "code": 103,
-                "message": f"Error: {str(exc)}",
-                "service": "metadata-service",
-                "type": "PATH_NOT_FOUND",
-            }
-        ),
-        400,
+@app.exception_handler(Exception)
+def handle_generic_exception(_req, exc):
+    logger.exception(exc)
+    return JSONResponse(
+        content={
+            "code": 202,
+            "message": f"Error: {str(exc)}",
+            "service": "metadata-service",
+            "type": "SYSTEM_ERROR",
+        },
+        status_code=500,
     )
 
 
-@app.errorhandler(DataNotFoundException)
-def handle_data_not_found(exc):
+@app.exception_handler(DataNotFoundException)
+def handle_data_not_found(_req, exc):
     logger.warning(exc, exc_info=True)
-    return jsonify(exc.to_dict()), 404
+    return JSONResponse(content=exc.to_dict(), status_code=404)
 
 
-@app.errorhandler(InvalidDraftVersionException)
-def handle_invalid_draft(exc):
+@app.exception_handler(InvalidDraftVersionException)
+def handle_invalid_draft(_req, exc):
     logger.warning(exc, exc_info=True)
-    return str(exc), 404
+    return JSONResponse(content={"message": str(exc)}, status_code=404)
 
 
-@app.errorhandler(RequestValidationException)
-def handle_invalid_request(exc):
+@app.exception_handler(RequestValidationException)
+def handle_invalid_request(_req, exc):
     logger.warning(exc, exc_info=True)
-    return jsonify(exc.to_dict()), 400
+    return JSONResponse(content=exc.to_dict(), status_code=400)
 
 
-@app.errorhandler(InvalidStorageFormatException)
-def handle_invalid_format(exc):
+@app.exception_handler(InvalidStorageFormatException)
+def handle_invalid_format(_req, exc):
     logger.exception(exc)
-    return jsonify(exc.to_dict()), 500
+    return JSONResponse(content=exc.to_dict(), status_code=500)
 
 
-# this is needed to run the application in IDE
 if __name__ == "__main__":
-    app.run(port=8000, host="0.0.0.0")
+    import uvicorn
+
+    uvicorn.run(app, host="0.0.0.0", port=8000)