add CODEOWNERS & GCF code, revise pkg version#s, update README

Author: wescpy

Diff for: .github/CODEOWNERS

@@ -0,0 +1,9 @@
+# Code owners file.
+# This file controls who is tagged for review for any given pull request.
+#
+# For syntax help see:
+# https://help.github.com/en/github/creating-cloning-and-archiving-repositories/about-code-owners#codeowners-syntax
+
+# The python-samples-owners team is the default owner for anything not
+# explicitly taken by someone else.
+*                               @wescpy @GoogleCloudPlatform/python-samples-owners

Diff for: README.md

@@ -21,7 +21,7 @@ Each codelab begins with a "START" code base then walks developers through that
 
 ## Cost
 
-App Engine is not a free service. While you may not have needed to enable billing in App Engine's early days, [all applications now require an active billing account](https://cloud.google.com/appengine/docs/standard/payment-instrument) backed by a financial instrument (usually a credit card). Don't worry, App Engine (and other GCP products) still have an ["Always Free" tier](https://cloud.google.com/free/docs/gcp-free-tier#always-free), and as long as you stay within those limits, you won't incur any charges. Also check the App Engine [pricing](https://cloud.google.com/appengine/pricing) and [quotas](https://cloud.google.com/appengine/quotas) pages for more information.
+App Engine is not a free service. While you may not have needed to enable billing in App Engine's early days, [all applications now require an active billing account](https://cloud.google.com/appengine/docs/standard/payment-instrument) backed by a financial instrument (usually a credit card). Don't worry, App Engine (and other GCP products) still have an ["Always Free" tier](https://cloud.google.com/free/docs/gcp-free-tier#free-tier-usage-limits) and as long as you stay within those limits, you won't incur any charges. Also check the App Engine [pricing](https://cloud.google.com/appengine/pricing) and [quotas](https://cloud.google.com/appengine/quotas) pages for more information.
 
 
 ## Why
@@ -68,10 +68,12 @@ Module | Topic | Codelab | START folder | FINISH folder
 3|Migrate to Cloud Datastore| [link](http://g.co/codelabs/pae-migrate-datastore) | Module 2 [code](/mod2a-cloudndb) (2.x) & [code](/mod2b-cloudndb) (3.x) | Module 3 [code](/mod3a-datastore) (2.x) & [code](/mod3b-datastore) (3.x)
 4|Migrate to Cloud Run with Docker| [link](http://g.co/codelabs/pae-migrate-rundocker) | Module 2 [code](/mod2a-cloudndb) (2.x) & Module 3 [code](/mod3b-datastore) (3.x) | Module 4 [code](/mod4a-rundocker) (2.x) & [code](/mod4b-rundocker) (3.x)
 5|Migrate to Cloud Run with Buildpacks| [link](http://g.co/codelabs/pae-migrate-runbldpks) | Module 2 [code](/mod2b-cloudndb) (3.x) | Module 5 [code](/mod5-runbldpks) (3.x)
-6|Migrate to Cloud Firestore| [link](http://g.co/codelabs/pae-migrate-firestore) | Module 3 [code]() (3.x) | Module 6 [code](/mod6-firestore) (3.x)
+6|Migrate to Cloud Firestore (app)| [link](http://g.co/codelabs/pae-migrate-firestore) | Module 3 [code](/mod3b-datastore) (3.x) | Module 6 [code](/mod6-firestore) (3.x)
 7|Add App Engine push tasks| [link](http://g.co/codelabs/pae-migrate-gaetasks) | Module 1 [code]() (2.x) | Module 7 [code](/mod7-gaetasks) (2.x)
 8|Migrate to Cloud Tasks| [link](http://g.co/codelabs/pae-migrate-cloudtasks) | Module 7 [code](/mod7-gaetasks) (2.x) | Module 8 [code](/mod8-cloudtasks) (2.x)
 9|Migrate to Python 3 (Cloud Datastore & Cloud Tasks v2)| [link](http://g.co/codelabs/pae-migrate-py3dstasks) | Module 8 [code](/mod8-cloudtasks) (2.x) | Module 9 [code](/mod9-py3dstasks) (3.x)
+10|Migrate to Cloud Firestore (data)| _N/A_ | _N/A_ | _TBD_
+11|Migrate to Cloud Functions| _TBD_ | Module 2 [code](/mod2b-cloudndb) (3.x) | Module 11 [code](/mod11-functions) (3.x)
 
 
 ### Table of contents
@@ -99,6 +101,7 @@ If there is a logical codelab to do immediately after completing one, they will
     - RECOMMENDED:
         - Module 7 - add App Engine (push) tasks
     - OTHERS (somewhat priority order):
+        - Module 11 - migrate to Cloud Functions
         - Module 5 - migrate to Cloud Run container with Cloud Buildpacks
         - Module 4 - migrate to Cloud Run container with Docker
         - Module 3 - migrate to Cloud Datastore
@@ -129,6 +132,7 @@ If there is a logical codelab to do immediately after completing one, they will
     - Python 3
         - FINISH: [Module 9 code - Cloud Datastore & Tasks](/mod9-py3dstasks) (3.x)
     - RECOMMENDED:
+        - Module 11 - migrate to Cloud Functions
         - Module 5 - migrate to Cloud Run container with Cloud Buildpacks
         - Module 4 - migrate to Cloud Run container with Docker
         - Module 6 - migrate to Cloud Firestore
@@ -146,6 +150,7 @@ If there is a logical codelab to do immediately after completing one, they will
         - Module 5 - migrate to Cloud Run container with Cloud Buildpacks
     - OTHER OPTIONS (in somewhat priority order):
         - Module 7 - add App Engine (push) tasks
+        - Module 11 - migrate to Cloud Functions
 
 - [Module 5 codelab](http://g.co/codelabs/pae-migrate-runbldpks): **Migrate from App Engine to [Cloud Run](http://cloud.google.com/run) with Cloud Buildpacks**
     - **Optional** migration
@@ -158,6 +163,7 @@ If there is a logical codelab to do immediately after completing one, they will
         - Module 4 - migrate to Cloud Run container with Docker
     - OTHER OPTIONS (in somewhat priority order):
         - Module 7 - add App Engine (push) tasks
+        - Module 11 - migrate to Cloud Functions
 
 - [Module 3 codelab](http://g.co/codelabs/pae-migrate-datastore): **Migrate from Cloud NDB to Cloud Datastore**
     - **Optional** migration
@@ -172,7 +178,9 @@ If there is a logical codelab to do immediately after completing one, they will
     - RECOMMENDED:
         - Module 7 - add App Engine (push) tasks
     - OTHER OPTIONS (in somewhat priority order):
+        - Module 11 - migrate to Cloud Functions
         - Module 5 - migrate to Cloud Run container with Cloud Buildpacks
+        - Module 4 - migrate to Cloud Run container with Docker
         - Module 6 - migrate to Cloud Firestore
 
 - [Module 6 codelab](http://g.co/codelabs/pae-migrate-firestore): **Migrate from Cloud Datastore to [Cloud Firestore](http://cloud.google.com/firestore)**
@@ -185,7 +193,9 @@ If there is a logical codelab to do immediately after completing one, they will
     - RECOMMENDED:
         - Module 7 - add App Engine (push) tasks
     - OTHER OPTIONS (in somewhat priority order):
+        - Module 11 - migrate to Cloud Functions
         - Module 5 - migrate to Cloud Run container with Cloud Buildpacks
+        - Module 4 - migrate to Cloud Run container with Docker
 
 
 ## Considerations for mobile developers
@@ -211,11 +221,11 @@ If your original app users does *not* have a user interface, i.e., mobile backen
 
 - App Engine Migration
     - [Migrate from Python 2 to 3](http://cloud.google.com/appengine/docs/standard/python/migrate-to-python3)
-    - [Migrate from App Engine `ndb` to Cloud NDB](http://cloud.google.com/appengine/docs/standard/python/migrate-to-python3/migrate-to-cloud-ndb) (Step 2)
-    - [App Engine `ndb` to Cloud NDB official sample app](https://github.com/GoogleCloudPlatform/python-docs-samples/tree/master/appengine/standard/migration/ndb/overview) (Step 2)
-    - [Migrate from App Engine `taskqueue` to Cloud Tasks](http://cloud.google.com/appengine/docs/standard/python/migrate-to-python3/migrate-to-cloud-ndb) (Steps 5a-5c)
-    - [App Engine `app.yaml` to Cloud Run `service.yaml` tool](http://googlecloudplatform.github.io/app-engine-cloud-run-converter) (Step 4a)
-    - [Migrate from App Engine `db` to `ndb`](http://cloud.google.com/appengine/docs/standard/python/ndb/db_to_ndb) ("Step -1"; only for reviving "dead" Python 2.5 apps for 2.7)
+    - [Migrate from App Engine `ndb` to Cloud NDB](http://cloud.google.com/appengine/docs/standard/python/migrate-to-python3/migrate-to-cloud-ndb) (Module 2)
+    - [App Engine `ndb` to Cloud NDB official sample app](https://github.com/GoogleCloudPlatform/python-docs-samples/tree/master/appengine/standard/migration/ndb/overview) (Module 2)
+    - [Migrate from App Engine `taskqueue` to Cloud Tasks](http://cloud.google.com/appengine/docs/standard/python/migrate-to-python3/migrate-to-cloud-ndb) (Modules 7-9)
+    - [App Engine `app.yaml` to Cloud Run `service.yaml` tool](http://googlecloudplatform.github.io/app-engine-cloud-run-converter) (Modules 4 and 5)
+    - [Migrate from App Engine `db` to `ndb`](http://cloud.google.com/appengine/docs/standard/python/ndb/db_to_ndb) ("Module -1"; only for reviving "dead" Python 2.5 apps for 2.7)
     - [Community contributed migration samples](https://github.com/GoogleCloudPlatform/appengine-python2-3-migration)
 
 - Python App Engine

Diff for: mod1-flask/requirements.txt

@@ -1 +1 @@
-Flask==1.1.2
+flask==1.1.2

Diff for: mod11-functions/.gcloudignore

@@ -0,0 +1,24 @@
+# This file specifies files that are *not* uploaded to Google Cloud Platform
+# using gcloud. It follows the same syntax as .gitignore, with the addition of
+# "#!include" directives (which insert the entries of the given .gitignore-style
+# file at that point).
+#
+# For more information, run:
+#   $ gcloud topic gcloudignore
+#
+.gcloudignore
+
+# Ignore source code control maintenance files
+.git
+.gitignore
+.hgignore
+.hg/
+
+# Python files
+*.pyc
+*.pyo
+__pycache__/
+/setup.cfg
+
+# no need to upload README
+README.md

Diff for: mod11-functions/README.md

@@ -0,0 +1,3 @@
+# Module 11 - Migrate from Google App Engine to Cloud Functions
+
+This repo folder is the corresponding code to the [Module 11 codelab](http://g.co/codelabs/pae-migrate-functions). The tutorial STARTs with the Python 3 code in the [Module 2 repo Python3 folder](/mod2b-cloudndb) and leads developers through migrating away from App Engine to Cloud Functions, culminating in the code in this folder.

Diff for: mod11-functions/main.py

@@ -0,0 +1,40 @@
+# Copyright 2020 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 render_template
+from google.cloud import ndb
+
+ds_client = ndb.Client()
+
+class Visit(ndb.Model):
+    'Visit entity registers visitor IP address & timestamp'
+    visitor   = ndb.StringProperty()
+    timestamp = ndb.DateTimeProperty(auto_now_add=True)
+
+def store_visit(remote_addr, user_agent):
+    'create new Visit entity in Datastore'
+    with ds_client.context():
+        Visit(visitor='{}: {}'.format(remote_addr, user_agent)).put()
+
+def fetch_visits(limit):
+    'get most recent visits'
+    with ds_client.context():
+        return (v.to_dict() for v in Visit.query().order(
+                -Visit.timestamp).fetch(limit))
+
+def visitme(request):
+    'main application (GET) handler'
+    store_visit(request.remote_addr, request.user_agent)
+    visits = fetch_visits(10)
+    return render_template('index.html', visits=visits)

Diff for: mod11-functions/requirements.txt

@@ -0,0 +1,2 @@
+flask==1.1.2
+google-cloud-ndb==1.8.0

Diff for: mod11-functions/templates/index.html

@@ -0,0 +1,16 @@
+<!doctype html>
+<html>
+<head>
+<title>VisitMe Example</title>
+<body>
+
+<h1>VisitMe example</h1>
+<h3>Last 10 visits</h3>
+<ul>
+{% for visit in visits %}
+    <li>{{ visit.timestamp.ctime() }} from {{ visit.visitor }}</li>
+{% endfor %}
+</ul>
+
+</body>
+</html>

Diff for: mod2a-cloudndb/requirements.txt

@@ -1,2 +1,2 @@
-Flask==1.1.2
-google-cloud-ndb==1.7.1
+flask==1.1.2
+google-cloud-ndb==1.8.0

Diff for: mod2b-cloudndb/requirements.txt

@@ -1,2 +1,2 @@
-Flask==1.1.2
-google-cloud-ndb==1.7.1
+flask==1.1.2
+google-cloud-ndb==1.8.0

Diff for: mod3a-datastore/requirements.txt

@@ -1,2 +1,2 @@
-Flask==1.1.2
+flask==1.1.2
 google-cloud-datastore==1.15.3

Diff for: mod3b-datastore/requirements.txt

@@ -1,2 +1,2 @@
-Flask==1.1.2
-google-cloud-datastore==2.1.0
+flask==1.1.2
+google-cloud-datastore==2.1.2

Diff for: mod4a-rundocker/Dockerfile

@@ -2,4 +2,4 @@ FROM python:2-slim
 WORKDIR /app
 COPY . .
 RUN pip install -r requirements.txt
-ENTRYPOINT ["python", "main.py"]
+ENTRYPOINT exec gunicorn -b :$PORT -w 2 main:app

Diff for: mod4a-rundocker/main.py

@@ -19,6 +19,7 @@
 ds_client = ndb.Client()
 
 class Visit(ndb.Model):
+    'Visit entity registers visitor IP address & timestamp'
     visitor   = ndb.StringProperty()
     timestamp = ndb.DateTimeProperty(auto_now_add=True)
 
@@ -31,16 +32,11 @@ def fetch_visits(limit):
     'get most recent visits'
     with ds_client.context():
         return (v.to_dict() for v in Visit.query().order(
-                -Visit.timestamp).fetch_page(limit)[0])
+                -Visit.timestamp).fetch(limit))
 
 @app.route('/')
 def root():
     'main application (GET) handler'
     store_visit(request.remote_addr, request.user_agent)
     visits = fetch_visits(10)
     return render_template('index.html', visits=visits)
-
-if __name__ == '__main__':
-    import os
-    app.run(debug=True, threaded=True, host='0.0.0.0',
-            port=int(os.environ.get('PORT', 8080)))

Diff for: mod4a-rundocker/requirements.txt

@@ -1,2 +1,3 @@
-Flask==1.1.2
-google-cloud-ndb==1.7.1
+gunicorn==19.10.0
+flask==1.1.2
+google-cloud-ndb==1.8.0

Diff for: mod4b-rundocker/Dockerfile

@@ -2,4 +2,4 @@ FROM python:3-slim
 WORKDIR /app
 COPY . .
 RUN pip install -r requirements.txt
-ENTRYPOINT ["python", "main.py"]
+ENTRYPOINT exec gunicorn -b :$PORT -w 2 main:app

Diff for: mod4b-rundocker/main.py

@@ -40,8 +40,3 @@ def root():
     store_visit(request.remote_addr, request.user_agent)
     visits = fetch_visits(10)
     return render_template('index.html', visits=visits)
-
-if __name__ == '__main__':
-    import os
-    app.run(debug=True, threaded=True, host='0.0.0.0',
-            port=int(os.environ.get('PORT', 8080)))

Diff for: mod4b-rundocker/requirements.txt

@@ -1,2 +1,3 @@
-Flask==1.1.2
-google-cloud-datastore==2.1.0
+gunicorn==20.1.0
+flask==1.1.2
+google-cloud-datastore==2.1.2

Diff for: mod5-runbldpks/Procfile

@@ -1 +1 @@
-web: python main.py
+web: gunicorn -b :$PORT -w 2 main:app

Diff for: mod5-runbldpks/main.py

@@ -12,36 +12,31 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-from datetime import datetime
 from flask import Flask, render_template, request
-from google.cloud import datastore
+from google.cloud import ndb
 
 app = Flask(__name__)
-ds_client = datastore.Client()
+ds_client = ndb.Client()
+
+class Visit(ndb.Model):
+    'Visit entity registers visitor IP address & timestamp'
+    visitor   = ndb.StringProperty()
+    timestamp = ndb.DateTimeProperty(auto_now_add=True)
 
 def store_visit(remote_addr, user_agent):
     'create new Visit entity in Datastore'
-    entity = datastore.Entity(key=ds_client.key('Visit'))
-    entity.update({
-        'timestamp': datetime.now(),
-        'visitor': '{}: {}'.format(remote_addr, user_agent),
-    })
-    ds_client.put(entity)
+    with ds_client.context():
+        Visit(visitor='{}: {}'.format(remote_addr, user_agent)).put()
 
 def fetch_visits(limit):
     'get most recent visits'
-    query = ds_client.query(kind='Visit')
-    query.order = ['-timestamp']
-    return query.fetch(limit=limit)
+    with ds_client.context():
+        return (v.to_dict() for v in Visit.query().order(
+                -Visit.timestamp).fetch(limit))
 
 @app.route('/')
 def root():
     'main application (GET) handler'
     store_visit(request.remote_addr, request.user_agent)
     visits = fetch_visits(10)
     return render_template('index.html', visits=visits)
-
-if __name__ == '__main__':
-    import os
-    app.run(debug=True, threaded=True, host='0.0.0.0',
-            port=int(os.environ.get('PORT', 8080)))

Diff for: mod5-runbldpks/requirements.txt

@@ -1,2 +1,3 @@
-Flask==1.1.2
-google-cloud-datastore==2.1.0
+gunicorn==20.1.0
+flask==1.1.2
+google-cloud-ndb==1.8.0

Diff for: mod6-firestore/requirements.txt

@@ -1,2 +1,2 @@
-Flask==1.1.2
+flask==1.1.2
 google-cloud-firestore==2.0.2

Diff for: mod7-gaetasks/requirements.txt

@@ -1 +1 @@
-Flask==1.1.2
+flask==1.1.2

Diff for: mod8-cloudtasks/requirements.txt

@@ -1,3 +1,3 @@
-Flask==1.1.2
+flask==1.1.2
 google-cloud-ndb==1.7.1
 google-cloud-tasks==1.5.0

Diff for: mod9-py3dstasks/requirements.txt

@@ -1,3 +1,3 @@
-Flask==1.1.2
+flask==1.1.2
 google-cloud-datastore==2.1.0
 google-cloud-tasks==2.1.0