Adding Cloud run system package sample

run/system-package/.dockerignore

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+Dockerfile
+.dockerignore
+__pycache__
+.pytest_cache

run/system-package/Dockerfile

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+# Copyright 2019 Google, LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Use the official Python image.
+# https://hub.docker.com/_/python
+FROM python:3.7
+
+# [START run_system_package_ubuntu]
+RUN apt-get update -y && apt-get install -y \
+  graphviz \
+  && apt-get clean
+# [END run_system_package_ubuntu]
+
+# Copy application dependency manifests to the container image.
+# Copying this separately prevents re-running pip install on every code change.
+COPY requirements.txt .
+
+# Install production dependencies.
+RUN pip install -r requirements.txt
+
+# Copy local code to the container image.
+ENV APP_HOME /app
+WORKDIR $APP_HOME
+COPY . .
+
+# Run the web service on container startup. 
+# Use gunicorn webserver with one worker process and 8 threads.
+# For environments with multiple CPU cores, increase the number of workers
+# to be equal to the cores available.
+CMD exec gunicorn --bind :$PORT --workers 1 --threads 8 main:app
+

run/system-package/README.md

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+# Cloud Run System Package Sample
+
+This sample shows how to use a CLI tool installed as a system package as part of a web service.
+
+Use it with the [Using system packages tutorial](https://cloud.google.com/run/docs/tutorials/system-packages).
+
+
+[![Run in Google Cloud][run_img]][run_link]
+
+[run_img]: https://storage.googleapis.com/cloudrun/button.svg
+[run_link]: https://console.cloud.google.com/cloudshell/editor?shellonly=true&cloudshell_image=gcr.io/cloudrun/button&cloudshell_git_repo=https://github.com/GoogleCloudPlatform/python-docs-samples&cloudshell_working_dir=run/system-package
+
+## Build
+
+```
+docker build --tag graphviz:python .
+```
+
+## Run Locally
+
+```
+docker run --rm -p 9090:8080 graphviz:python
+```
+
+## Test
+
+```
+pytest
+```
+
+_Note: you may need to install `pytest` using `pip install pytest`._
+
+## Deploy
+
+```sh
+# Set an environment variable with your GCP Project ID
+export GOOGLE_CLOUD_PROJECT=<PROJECT_ID>
+
+# Submit a build using Google Cloud Build
+gcloud builds submit --tag gcr.io/${GOOGLE_CLOUD_PROJECT}/graphviz
+
+# Deploy to Cloud Run
+gcloud beta run deploy graphviz --image gcr.io/${GOOGLE_CLOUD_PROJECT}/graphviz
+```

run/system-package/main.py

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+# Copyright 2019 Google, LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from flask import Flask, make_response, request
+import os
+import subprocess
+import sys
+
+
+app = Flask(__name__)
+
+
+# [START run_system_package_handler]
+@app.route("/diagram.png", methods=["GET"])
+def index():
+    # Takes an HTTP GET request with query param dot and
+    # returns a png with the rendered DOT diagram in a HTTP response.
+    try:
+        image = create_diagram(request.args.get("dot"))
+        response = make_response(image)
+        response.headers.set("Content-Type", "image/png")
+        return response
+
+    except Exception as e:
+        print(f"error: {e}")
+
+        # Flush the stdout to avoid log buffering.
+        sys.stdout.flush()
+
+        # If no graphviz definition or bad graphviz def, return 400
+        if "syntax" in str(e):
+            return f"Bad Request: {e}", 400
+
+        return "Internal Server Error", 500
+
+
+# [END run_system_package_handler]
+
+
+# [START run_system_package_exec]
+def create_diagram(dot):
+    # Generates a diagram based on a graphviz DOT diagram description.
+    if not dot:
+        raise Exception("syntax: no graphviz definition provided")
+
+    dot_args = [  # These args add a watermark to the dot graphic.
+        "-Glabel=Made on Cloud Run",
+        "-Gfontsize=10",
+        "-Glabeljust=right",
+        "-Glabelloc=bottom",
+        "-Gfontcolor=gray",
+        "-Tpng",
+    ]
+
+    # Uses local `dot` binary from Graphviz:
+    # https://graphviz.gitlab.io
+    image = subprocess.run(
+        ["dot"] + dot_args, input=dot.encode("utf-8"), stdout=subprocess.PIPE
+    ).stdout
+
+    if not image:
+        raise Exception("syntax: bad graphviz definition provided")
+    return image
+
+
+# [END run_system_package_exec]
+
+
+if __name__ == "__main__":
+    PORT = int(os.getenv("PORT")) if os.getenv("PORT") else 8080
+
+    # This is used when running locally. Gunicorn is used to run the
+    # application on Cloud Run. See entrypoint in Dockerfile.
+    app.run(host="127.0.0.1", port=PORT, debug=True)

run/system-package/main_test.py

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+# Copyright 2019 Google, LLC.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# NOTE:
+# To pass these tests locally, run `brew install graphviz`
+
+
+import main
+import pytest
+
+
+@pytest.fixture
+def client():
+    main.app.testing = True
+    return main.app.test_client()
+
+
+def test_empty_query_string(client):
+    r = client.get("/diagram.png")
+    assert r.status_code == 400
+
+
+def test_empty_dot_parameter(client):
+    r = client.get("/diagram.png?dot=")
+    assert r.status_code == 400
+
+
+def test_bad_dot_parameter(client):
+    r = client.get("/diagram.png?dot=digraph")
+    assert r.status_code == 400
+
+
+def test_good_dot_parameter(client):
+    r = client.get("/diagram.png?dot=digraph G { A -> {B, C, D} -> {F} }")
+    assert r.content_type == "image/png"

run/system-package/requirements.txt

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+Flask==1.1.1
+pytest==5.1.3
+gunicorn==19.9.0