Add Docker files, update README

[Phu2]

This PR adds the ability to setup playground with docker. Both in development and production mode.

[Phu2]

@fsteeg Please try out the development mode.

[fsteeg]

Added port mappings for lein watch (runs on 8280, uses something on 9630) and updated README with links to the local server. With this, for me the playground starts in dev mode and can be used to run workflows. When I edit code however, it's not reflected in the running instance (which plain lein watch should do).

(You did not ask me to review it, but I still tried prod mode, but that is not working for me: logs look good, but can't connect on port 3000.)

[Phu2]

Added port mappings for lein watch (runs on 8280, uses something on 9630) and updated README with links to the local server. With this, for me the playground starts in dev mode and can be used to run workflows.

Thank you! ❤️

When I edit code however, it's not reflected in the running instance (which plain lein watch should do).

Because i forgot to add a bind mount from the project folder on the host to the container, caught up with 8a8b9eb

(You did not ask me to review it, but I still tried prod mode, but that is not working for me: logs look good, but can't connect on port 3000.)

Some docker caching is getting in the way, i think. When starting a second mode, you have to use the flag --force-recreate, eg. docker compose up --force-recreate, forcing Docker to create the container anew.
Hopefully, by adding different project names and environments respectively we have a cleaner solution. See this commit a925d77
Now you should be able to start both modes independently and in parallel. Check running containers with docker ps.

[fsteeg]

Picking up code changes in dev mode now works! 👍

Prod mode also starts, I can access and run examples in general. However, I get a java.security.AccessControlException: access denied ("java.io.FilePermission" "/opt/.project" "read") when running http://localhost:3000/?example=How+to+use+the+Playground

[Phu2]

Prod mode also starts, I can access and run examples in general. However, I get a java.security.AccessControlException: access denied ("java.io.FilePermission" "/opt/.project" "read") when running http://localhost:3000/?example=How+to+use+the+Playground

Thanks! Changed installation directory from /opt to /home/playground in order to match permissions set in the provided java policy template. We are using this template as is without any modification. See adbc52f

Please execute docker compose -f docker-compose-dev.yml up --build --force-recreate for Docker to rebuild the underlying image. Otherwise Docker won't pick up changes made in the Dockerfile. (Look for lines beginning with => CACHED in the output of the docker compose command)

You also may want to cleanup unused images and reduce disk usage. Check: docker image ls and delete all unused images: docker image prune -a.

[fsteeg]

Great! The example now works, both in dev and prod mode.