Merge pull request #261 from RDFLib/function_app_patches

Update Azure Function app files

.dockerignore

@@ -6,6 +6,7 @@ venv/
 .vscode/
 .idea/
 .git/
+build/
 test_*.py
 .github/
 Dockerfile

.gitignore

@@ -6,6 +6,7 @@ __pycache__/
 .pytest_cache/
 .env*
 dist/
+build/
 !.env-template
 rdf/
 http/

azure/.funcignore

@@ -0,0 +1,7 @@
+.vscode/
+.venv/
+.idea/
+__pycache__/
+__pycache__
+local.settings.json
+

azure/README.md

@@ -0,0 +1,39 @@
+# Prez Azure Function-App deployment files
+
+This directory contains the files required to build and start or publish Prez as an Azure Function-App, as well as a Dockerfile that 
+can be used to build a container image for deploying the app as an Azure Container App.
+
+## Publishing
+There is a publish_or_start.sh script that can be used to either build and run the function app locally, or publish the app to Azure.
+To call it, make sure you are not in the "azure" directory, instead run the script from the root of the project.
+
+```bash
+./azure/publish_or_start.sh start|publish <function-app-name> --extra-options 
+```
+The FunctionAppName is required for publishing only, and is the name of the Azure Function-App that you want to publish to.
+Note, the FunctionAppName must be the second argument to the script, after any optional arguments.
+
+This script will perform the following steps:
+1. Create a ./build directory
+2. Copy the required azure function files from the ./azure directory into the ./build directory
+  * ./azure/function_app.py
+  * ./azure/patched_asgi_function_wrapper.py
+  * ./azure/host.json
+  * ./azure/.funcignore
+3. Copy the local prez module source code into the ./build directory
+4. Copy the .env file into the ./build directory if it exists
+5. Copy the pyproject.toml and poetry.lock files into the ./build directory
+6. Generate the requirements.txt file using poetry
+7. Start the app locally, or publish the app to the Azure Function-App (using remote build)
+
+**extra-options** can be used to pass additional arguments to the azure publish command. (Eg, the `--subscription` argument)
+
+_Note:_ the script automatically adds the `--build remote` argument to the publish command, you don't need to specify it.
+
+## Building the Docker container image
+
+To build the Docker container image, run the following command from the root of the project:
+
+```bash
+docker build -t <image-name> -f azure/azure_functions.Dockerfile .
+```

azure_functions.Dockerfile → azure/azure_functions.Dockerfile

@@ -19,7 +19,7 @@ RUN pip3 install poetry==${POETRY_VERSION}
 RUN mkdir -p /build
 WORKDIR /build
 
-COPY . .
+COPY .. .
 RUN poetry build
 
 RUN mkdir -p /home/site/wwwroot
@@ -52,7 +52,7 @@ RUN DEBIAN_FRONTEND=noninteractive apt-get -qq update && \
       bash
 
 WORKDIR /home/site/wwwroot
-COPY requirements.txt pyproject.toml host.json function_app.py ./
+COPY pyproject.toml poetry.lock azure/host.json azure/function_app.py azure/patched_asgi_function_wrapper.py ./
 
 ENTRYPOINT []
 CMD ["/opt/startup/start_nonappservice.sh"]

function_app.py → azure/function_app.py

@@ -1,18 +1,29 @@
 import os
-import azure.functions as func
+import sys
+import pathlib
+import logging
+
+cwd = pathlib.Path(__file__).parent
+if cwd.name == "azure":
+    # We are running from the repo source directory
+    # assume running locally, we need to add the parent
+    # directory to the Python Path
+    sys.path.append(str(cwd.parent))
 
+import azure.functions as func
 
 try:
     from prez.app import assemble_app
-except ImportError:
+except ImportError as e:
+    logging.exception("Cannot import prez")
     assemble_app = None
 
 
 if assemble_app is None:
     raise RuntimeError(
-        "Cannot import prez in the Azure function app. Check requirements.py and pyproject.toml."
+        "Cannot import prez in the Azure function app. Check requirements.txt and pyproject.toml."
     )
-
+from patched_asgi_function_wrapper import AsgiFunctionApp
 
 # This is the base URL path that Prez routes will stem from
 # must _start_ in a slash, but _not end_ in slash, eg: /prez
@@ -32,7 +43,7 @@
 
 prez_app = assemble_app(root_path=ROOT_PATH)
 
-app = func.AsgiFunctionApp(app=prez_app, http_auth_level=auth_level)
+app = AsgiFunctionApp(app=prez_app, http_auth_level=auth_level)
 
 if __name__ == "__main__":
     from azure.functions import HttpRequest, Context
@@ -41,7 +52,11 @@
     req = HttpRequest("GET", "/catalogs", headers={}, body=b"")
     context = dict()
     loop = asyncio.get_event_loop()
-
-    task = app.middleware.handle_async(req, context)
+    fns = app.get_functions()
+    assert len(fns) == 1
+    fn_def = fns[0]
+    fn = fn_def.get_user_function()
+    task = fn(req, context)
     resp = loop.run_until_complete(task)
     print(resp)
+

azure/patched_asgi_function_wrapper.py

@@ -0,0 +1,63 @@
+from typing import Union, TYPE_CHECKING
+from copy import copy
+import azure.functions as func
+from azure.functions.decorators.http import HttpMethod
+from azure.functions._http_asgi import AsgiMiddleware, AsgiRequest, AsgiResponse
+from azure.functions._http_wsgi import WsgiMiddleware
+from azure.functions._abc import Context
+from azure.functions import HttpRequest
+
+# -------------------
+# Create a patched AsgiFunctionApp to fix the ASGI scope state issue
+# -------------------
+# See https://github.com/Azure/azure-functions-python-worker/issues/1566
+class MyAsgiMiddleware(AsgiMiddleware):
+    async def _handle_async(self, req, context):
+        asgi_request = AsgiRequest(req, context)
+        scope = asgi_request.to_asgi_http_scope()
+        # shallow copy the state as-per the ASGI spec
+        scope["state"] = copy(self.state)  # <-- this is the patch, add the state to the scope
+        asgi_response = await AsgiResponse.from_app(self._app,
+                                                    scope,
+                                                    req.get_body())
+        return asgi_response.to_func_response()
+
+# -------------------
+# Create a patched AsgiFunctionApp to fix the double-slash route issue
+# -------------------
+# See https://github.com/Azure/azure-functions-python-worker/issues/1310
+class AsgiFunctionApp(func.AsgiFunctionApp):
+    def __init__(self, app, http_auth_level):
+        super(AsgiFunctionApp, self).__init__(None, http_auth_level=http_auth_level)
+        self._function_builders.clear()
+        self.middleware = MyAsgiMiddleware(app)
+        self._add_http_app(self.middleware)
+        self.startup_task_done = False
+
+    def _add_http_app(
+            self, http_middleware: Union[AsgiMiddleware, WsgiMiddleware]
+    ) -> None:
+        """Add an Asgi app integrated http function.
+
+        :param http_middleware: :class:`WsgiMiddleware`
+                                or class:`AsgiMiddleware` instance.
+
+        :return: None
+        """
+
+        asgi_middleware: AsgiMiddleware = http_middleware
+
+        @self.http_type(http_type="asgi")
+        @self.route(
+            methods=(method for method in HttpMethod),
+            auth_level=self.auth_level,
+            route="{*route}",  # <-- this is the patch, removed the leading slash from the route
+        )
+        async def http_app_func(req: HttpRequest, context: Context):
+            if not self.startup_task_done:
+                success = await asgi_middleware.notify_startup()
+                if not success:
+                    raise RuntimeError("ASGI middleware startup failed.")
+                self.startup_task_done = True
+
+            return await asgi_middleware.handle_async(req, context)

azure/publish_or_start.sh

@@ -0,0 +1,67 @@
+#!/bin/bash
+DEFAULT_FUNC=$(which func)
+DEFAULT_POETRY=$(which poetry)
+FUNC_CLI=${FUNC_CLI:-"$DEFAULT_FUNC"}
+POETRY=${POETRY:-"$DEFAULT_POETRY"}
+
+if [[ "$#" -lt 1 ]] ; then
+  echo "Usage: $0 <start|publish> [optional arguments] [FunctionAppName]"
+  echo "  start: Run the function app locally (FunctionAppName not required)"
+  echo "  publish: Publish the function app to Azure (FunctionAppName required)"
+  exit 1
+fi
+
+# Extract the first argument as the ACTION
+ACTION="$1"
+shift
+
+CWD="$(pwd)"
+BASE_CWD="${CWD##*/}"
+if [[ "$BASE_CWD" = "azure" ]] ; then
+  echo "Do not run this script from within the azure directory"
+  echo "Run from the root of the repo"
+  echo "eg: ./azure/publish_or_start.sh start"
+  exit 1
+fi
+
+if [[ -z "$FUNC_CLI" ]] ; then
+    echo "func cli not found, specify the location using env FUNC_CLI"
+    exit 1
+fi
+
+if [[ -z "$POETRY" ]] ; then
+    echo "poetry not found. Local poetry>=1.8.2 is required to generate the requirements.txt file"
+    echo "specify the location using env POETRY"
+    exit 1
+fi
+
+mkdir -p build
+rm -rf build/*
+cp ./azure/function_app.py ./azure/patched_asgi_function_wrapper.py ./azure/.funcignore ./azure/host.json ./azure/local.settings.json build/
+cp ./pyproject.toml ./poetry.lock ./build
+cp -r ./prez ./build
+if [[ -f "./.env" ]] ; then
+    cp ./.env ./build
+fi
+cd ./build
+"$POETRY" export --without-hashes --format=requirements.txt > requirements.txt
+echo "generated requirements.txt"
+cat ./requirements.txt
+
+if [[ "$ACTION" == "publish" ]] ; then
+  if [[ "$#" -lt 1 ]] ; then
+    echo "Error: FunctionAppName is required for publish action"
+    exit 1
+  fi
+  FUNC_APP_NAME="$1"
+  shift
+  "$FUNC_CLI" azure functionapp publish "$FUNC_APP_NAME" --build remote "$@"
+elif [[ "$ACTION" == "start" ]] ; then
+  "$FUNC_CLI" start "$@"
+else
+  echo "Invalid action. Use 'start' for local testing or 'publish' for publishing to Azure."
+  exit 1
+fi
+
+cd ..
+echo "You can now delete the build directory if you wish."