Add a --watch option for docker development

[barakbd]

We are using public.ecr.aws/lambda/python:3.8which uses rie as an entrypoint. We use docker as a local development environment, so we do not need to setup a python virtualenv and avoid "it works on my machine" errors. We map the source code into the container using a volume and at the moment the only way to get the container to the run the latest changes, is docker-compose restart CONTAINER-NAME.

This is not ideal and we would appreciate having a --watch flag added to rie such that we could add it to the docker-compose command option, e.g. ["app.handler", "--watch"]. This flag would rerun the server inside the container upon changes, similar to Flask's runserver.

[o-alexandrov]

If adding a watcher is not feasible, please advise on the proper steps to:

• reevaluate the function's handler (or restart the process) within the lambda container
  • so there's no need to restart the container

This way, a watcher outside of the docker container could send a command to the running container to restart the process.

[govindrai]

Any updates on this? This is a huge impediment to local development.