Infra: Sharing my Bazel rules for GAE and GCF deployments.

.gitignore

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+__pycache__/
+bazel-*
+*.py[co]

.vscode/settings.json

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+{
+  "python.formatting.provider": "yapf",
+  "python.pythonPath": "/usr/bin/python3",
+  "files.exclude": {
+      "**/__pycache__": true,
+      "**/bazel-*": true
+  },
+}

LICENSE

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+Copyright 2018 Google LLC. All rights reserved.
+
+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
+
+    https://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.

README.rst

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+================================================================
+Bazel Rules: Python 3 Google App Engine & Google Cloud Functions
+================================================================
+
+This repository contains the `Bazel <https://bazel.build>`_ (`Starlark <https://docs.bazel.build/versions/master/skylark/language.html>`_) rules to build Python 3 and deploy to Google App Engine and Google Cloud Functions.
+
+Usage
+=====
+
+There is a `GAE app example <examples/app_engine/BUILD>`_ and `a GCF example <examples/function/BUILD>`_ in the ``examples`` directory.
+
+Google App Engine (Python 3)
+----------------------------
+
+Put this in the ``BUILD`` file::
+
+  py_binary(
+      name = "app",
+      srcs = [
+          "app.py",
+      ],
+  )
+
+  py_app_engine(
+      name = "app_deploy",
+      src = ":app",
+      descriptor = "app.yaml",
+      entry = "app",
+      requirements = [
+          "flask",
+      ],
+  )
+
+and run::
+
+  examples$ bazel run //app_engine:app_deploy
+
+Google Cloud Functions (Python 3)
+---------------------------------
+
+Put this in the ``BUILD`` file::
+
+  py_binary(
+      name = "hello",
+      srcs = [
+          "hello.py",
+      ],
+  )
+
+  py_cloud_function(
+      name = "hello_deploy",
+      src = ":hello",
+      entry = "hello",
+  )
+
+and run::
+
+  examples$ bazel run //function:hello_deploy
+
+Features
+========
+
+In the BUILD rule you can also specify:
+
+PyPI (pip) requirements
+  either as a package list or pointing to a ``requirements.txt`` file
+
+The GCP project name
+  if you don't want to use the default one used by ``gcloud``
+
+Version (App Engine only)
+  the version string of the GAE deployment
+
+Deploy name (Cloud Functions only)
+  the name of the deployed function (in GCP) and also in the HTTP path
+
+Pub/Sub topic trigger (Cloud Functions only)
+  if you want your function to be triggered by a Cloud Pub/Sub message
+
+GCS bucket trigger (Cloud Functions only)
+  if you want your function to be triggered by events from a GCS bucket
+
+Memory in MiB (Cloud Functions only)
+  the default is 256 MiB but you can request more, up to 2,048 MiB
+
+Timeout in seconds (Cloud Functions only)
+  the default is 60 s but you can request up to 540 s.
+
+Requirements
+============
+
+This solution depends on these commands being available:
+
+* The Python 3 interpreter at ``/usr/bin/python3``
+* `The fish shell <http://fishshell.com/>`_ at ``fish``
+* `The Google Cloud SDK <https://cloud.google.com/sdk/>`_ at ``gcloud``
+
+Your Bazel workspace should be set to generate a ZIP package for ``py_binary`` targets, by setting some parameters in the ``.bazelrc`` file, `like this <examples/.bazelrc>`_.
+
+LICENSE
+=======
+
+``bazel_for_gcloud_python`` is released under `the Apache 2.0 License <LICENSE>`_.

WORKSPACE

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+workspace(name = "bazel_for_gcloud_python")

examples/.bazelrc

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+# Use Python 3 and build to ZIP.
+run --python_top=//dev/env:python3 --build_python_zip
+build --python_top=//dev/env:python3 --build_python_zip

examples/WORKSPACE

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+workspace(name = "bazel_for_gcloud_python_examples")
+
+local_repository(
+    name = "bazel_for_gcloud_python",
+    path = "../",
+)
+
+# Or, use the git repository (and comment the above):
+# load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+# git_repository(
+#     name = "bazel_for_gcloud_python",
+#     remote = "https://github.com/weisi/bazel_for_gcloud_python.git",
+#     commit = "Replace this with a Git commit SHA",
+# )

examples/app_engine/BUILD

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+load("@bazel_for_gcloud_python//infra/serverless:gae_rules.bzl", "py_app_engine")
+
+py_library(
+    name = "gae_utils",
+    srcs = ["gae_utils.py"],
+    deps = [
+        "//function:gcf_utils",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+py_binary(
+    name = "app",
+    srcs = [
+        "app.py",
+    ],
+    data = [
+        "static/file.html",
+    ],
+    deps = [
+        ":gae_utils",
+    ],
+)
+
+# 'bazel run' this rule to trigger deployment.
+py_app_engine(
+    # Required parameters:
+    name = "app_deploy",
+    src = ":app",
+    descriptor = "app.yaml",
+    entry = "app",
+
+    # Specify your pip requirements here
+    requirements = [
+        # flask is required.
+        "flask",
+    ],
+
+    # Specify a GCP project name instead of using the default:
+    # gcloud_project = "my-gcp-project",
+
+    # Print the arguments for debugging when running the rule:
+    # debug = True,
+)

examples/app_engine/app.py

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+from flask import Flask, request
+
+from app_engine import gae_utils
+
+app = Flask(__name__)
+
+@app.route('/')
+@gae_utils.plain_text_response
+def homepage():
+  messages = list()
+  messages.append('Hi there,')
+  messages.append(f'You are visiting path "{request.path}".')
+  messages.append(
+    f'This app "{gae_utils.current_application_name()}" '
+    f'is running on GCP project {gae_utils.current_gcloud_project()}.'
+  )
+  messages.append(f'Your IP address is {gae_utils.remote_ip()}')
+  messages.append('Visit any other path to see a static file.')
+  return '\n'.join(messages)

examples/app_engine/app.yaml

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+runtime: python37
+# service: service-name
+instance_class: F1
+automatic_scaling:
+  min_instances: 0
+  max_instances: 1
+handlers:
+- url: /$
+  secure: always
+  script: auto
+- url: /.*$
+  static_files: app_engine/static/file.html
+  upload: app_engine/static/file\.html
+  secure: always

examples/app_engine/gae_utils.py

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+# Helper methods for using Python 3 on Google App Engine.
+# Don't use gcf_utils directly if running on GAE, since some details are different.
+
+from flask import request, Response
+import http
+import os
+
+from function.gcf_utils import \
+    plain_text_response, \
+    http_no_content, \
+    current_gcloud_project, \
+    remote_ip
+
+
+def current_application_name():
+    # In the form of 's~xcode-dev'.
+    return os.environ.get('GAE_APPLICATION')
+
+
+def current_service_name():
+    return os.environ.get('GAE_SERVICE')
+
+
+def current_version():
+    return os.environ.get('GAE_VERSION')
+
+
+def current_instance():
+    # It's the GAE instance ID, a.k.a. "clone_id".
+    return os.environ.get('GAE_INSTANCE')

examples/app_engine/static/file.html

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+<!DOCTYPE html>
+<html lang="en">
+
+<head>
+  <meta charset="UTF-8">
+  <title>Hello, static file</title>
+</head>
+
+<body>
+  <h3>Hello, static file</h3>
+  <p>This is a static file, served on Google App Engine.</p>
+</body>
+
+</html>

examples/dev/env/BUILD

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+py_runtime(
+    name = "python3",
+    files = [],
+    interpreter_path = "/usr/bin/python3",
+    visibility = ["//visibility:public"],
+)

examples/function/BUILD

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+load("@bazel_for_gcloud_python//infra/serverless:gcf_rules.bzl", "py_cloud_function")
+
+py_library(
+    name = "gcf_utils",
+    srcs = [
+        "gcf_utils.py",
+    ],
+    visibility = ["//visibility:public"],
+)
+
+py_binary(
+    name = "hello",
+    srcs = [
+        "hello.py",
+    ],
+    deps = [
+        ":gcf_utils",
+    ]
+)
+
+# 'bazel run' this rule to trigger deployment.
+py_cloud_function(
+    # Required parameters:
+    name = "hello_deploy",
+    src = ":hello",
+    entry = "hello",
+
+    # Specify your pip requirements here:
+    # requirements = [
+    #   "google-cloud-logging",
+    # ],
+
+    # or specify them in another file:
+    # requirements_file = "//function:requirements.txt"
+
+    # Specify a GCP project name instead of using the default:
+    # gcloud_project = "my-gcp-project",
+
+    # The function name that appears in HTTP path:
+    # deploy_name = "function_name",
+
+    # Use pubsub as a trigger instead of HTTP:
+    # trigger_topic = "pubsub_topic",
+
+    # Use GCS as a trigger instead of HTTP:
+    # trigger_bucket = "my_gcs_bucket",
+
+    # Specify the memory limit in MiB (default is 256 MiB):
+    # memory = 2048,
+
+    # Specify the timeout of the function in seconds (default is 60 s):
+    # timeout = 200,
+
+    # Print the arguments for debugging when running the rule:
+    # debug = True,
+)

examples/function/gcf_utils.py

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+from flask import request, Response
+import http
+import os
+
+
+def plain_text_response(fn):
+    def _wrapper(*args, **kwargs):
+        return Response(fn(*args, **kwargs), mimetype='text/plain')
+
+    _wrapper.__name__ = fn.__name__
+    return _wrapper
+
+
+def http_no_content(fn):
+    def _wrapper(*args, **kwargs):
+        fn(*args, **kwargs)
+        return (str(), http.HTTPStatus.NO_CONTENT)
+
+    _wrapper.__name__ = fn.__name__
+    return _wrapper
+
+
+def execution_id():
+    return request.headers.get('Function-Execution-Id')
+
+
+def remote_ip():
+    return request.headers.get('X-Appengine-User-Ip')
+
+
+def current_gcloud_project():
+    return os.environ.get('GCP_PROJECT') \
+        or os.environ.get('GCLOUD_PROJECT') \
+        or os.environ.get('GOOGLE_CLOUD_PROJECT')
+
+
+def current_function_name():
+    return os.environ.get('FUNCTION_NAME')
+
+
+def current_function_region():
+    return os.environ.get('FUNCTION_REGION')

examples/function/hello.py

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+from function import gcf_utils
+
+@gcf_utils.plain_text_response
+def hello(request):
+  messages = list()
+  messages.append('Hi there,')
+  messages.append(f'You are visiting path "{request.path}".')
+  messages.append(
+    f'This function "{gcf_utils.current_function_name()}" '
+    f'is running on GCP project {gcf_utils.current_gcloud_project()}.'
+  )
+  messages.append(f'Your IP address is {gcf_utils.remote_ip()}')
+  return '\n'.join(messages)