Tools around a sample serverless app to automate the drudgery associated with a project. Testing with pytest and coverage; code smells with flake8; documentation with Sphinx for HTML/ePub output; different deployment environments based on code repo branch (dev, qa, prod, and per-developer); CI/CD pipeline to run all this, including deployment to separate AWS environments. And a simple app with API Gateway, Lambda, S3, DynamoDB.

1. A Scaffolding for Serverless Apps
Chris Shenton: CTO, V! Studios
AWS Meetup Arlington VA
2018-02-27

2. Drudgery, Automated
● Test framework
● Documentation
● Code smells
● Multiple stages, environments
● CI/CD
● Deployment to cloud
● Starter app
○ Lambda with Python3
○ File upload to S3
○ Metadata to DynamoDB
○ Soon: Angular2+ front-end

3. Testing: py.test with test coverage
(.venv3) chris@Haruspex:scaffold-serverless$ make tests
PIP INSTALLING REQUIREMENTS
.venv3/bin/pip install -r requirements.txt
================================================= test session starts
plugins: cov-2.5.1
collected 1 item
tests/test_example.py .
[100%]Coverage.py warning: No data was collected. (no-data-collected)
--------- generated xml file:
/Users/chris/Projects/vstudios/scaffold-serverless/test-results/junit/junit.xml ---------
---------- coverage: platform darwin, python 3.6.3-final-0 -----------
Name Stmts Miss Branch BrPart Cover Missing
------------------------------------------------------------
app/handler.py 55 55 16 0 0% 1-93
Coverage HTML written to dir test-results/coverage
============================================== 1 passed in 2.53 seconds

4. Documentation: Sphinx generates HTML, ePub
(.venv3) chris@Haruspex:scaffold-serverless$ make docs
cd docs && make SPHINXBUILD=../.venv3/bin/sphinx-build html singlehtml epub
Running Sphinx v1.6.7
reading sources... [ 20%] api
reading sources... [ 40%] cicd
reading sources... [ 60%] index
reading sources... [ 80%] stage-envs
reading sources... [100%] todo
generating indices... genindex
writing additional pages... search
copying images... [100%] cicd-dashboard.png
dumping search index in English (code: en) ... done
build succeeded.
Build finished. The HTML pages are in _build/html.
Build finished. The HTML page is in _build/singlehtml.
Build finished. The ePub file is in _build/epub.

5. Code Smells: Linting with Flake8
(.venv3) chris@Haruspex:scaffold-serverless$ make flake8
.venv3/bin/flake8 app/
app/handler.py:73:52: E222 multiple spaces after operator
app/handler.py:95:1: W391 blank line at end of file
make: *** [flake8] Error 1

6. Multiple Stages, Cloud Environments
Repo
Branch
AWS Stage
Environment
Comment
master prod conventional name for production systems
release/* qa quality assurance before release to
production
develop dev default stage name for Serverless
Framework
feature/* $CIRCLE_USERNAME each developer gets their own
environment, named after their GitHub
username

7. CI/CD: CircleCI every branch -- build and test, then deploy

8. Deployment: to multiple AWS environments

9. Starter App: Lambda with Python, API, DynamoDB
API Gateway
/assets
API Gateway
/upload_url
Lambda
s3upload()
Get file metadata from
S3: name, size, etag;
store to DynamoDB
Lambda
get_upload_url()
Return presigned URL
allowing upload
without credentials
Lambda
get_assets()
Return metadata as
JSON or HTML
DynamoDB
Uploads
id, size, etag, bucket
S3 Bucket
Uploads
Save file metadata
Read all metadata

10. Contact and Code
chris@v-studios.com
@shentonfreude
https://github.com/v-studios/scaffold-serverless