Motivation

Webapp extensions such as:

• https://github.com/localstack/localstack-ngrok-tunnels
• https://github.com/thrau/localstack-aws-log-viewer
• https://github.com/localstack/localstack-extension-event-studio

Follow a common pattern. They

• expose routes through subdomains and submounts (http://my-extension.localhost.localstack.cloud:4566, and http://localhost.localstack.cloud:4566/_extension/my-extension)
• Enable logging for their root module my_extension
• Serve jinja2 templates
• Serve static files

Their file layout will typically look like this:

my_extension
├── extension.py
├── __init__.py
├── static              <-- make sure static resources get packaged!
│   ├── __init__.py
│   ├── favicon.ico
│   └── style.css
└── templates            <-- jinja2 templates
   └── index.html

This PR introduces this pattern as a class that can be extended to quickly develop extensions like this.

Examples of how existing extensions have been simplified can be found in:

• refactor extension using new WebAppExtension pattern thrau/localstack-aws-log-viewer#1
• https://github.com/localstack/localstack-ngrok-tunnels/commit/1838953260e44ca31046928f9576c7902abc17d1
• https://github.com/localstack/localstack-extension-event-studio

Requires Rolo v0.5.0

Changes

• Introduce localstack.extension.patterns
• Add a high-level pattern WebAppExtension

Testing

If you want to test this you can:

• download and checkout refactor extension using new WebAppExtension pattern thrau/localstack-aws-log-viewer#1 (or just build your own extension if you want)
  • run make install
  • run localstack extensions dev enable .
• checkout this branch
• in localstack-ext, run EXTENSION_DEV_MODE=1 python -m localstack.dev.run -e LOCALSTACK_API_KEY=test -e EXTENSION_DEV_MODE=1

TODO

What's left to do:

• Wait for rolo dependency to be updated v0.5.0