feat: Containerize WebSocket server

[benjreinhart]

SUMMARY

This adds Docker and docker-compose support for the websocket server.

Notes

Since we support development both with and without Docker, we need to make sure that any node_modules and dist folders/files from the host machine are not copied into the container, those should be freshly installed/compiled. .dockerignore ensures that COPY commands in the Dockerfile will not carry those folders over when building the image with docker build. However, this did not seem to work when running the service with docker-compose. Instead, it works to mount fake volumes for those folders in the compose file. Since the compose file is for development, I think it's ok to go with this somewhat hacky solution (it seems to work fine).

Try it out

For example, if you want to run superset via docker with async queries via websockets, you can:

1. Ensure you properly configure async queries (and whatever else) in docker/pythonpath_dev/superset_config_docker.py
2. Boot relevant superset services with docker-compose, e.g.,

    docker-compose up superset superset-websocket superset-worker
   

cc @robdiciuccio @stevenuray

[benjreinhart]

This is the most recent LTS version, which is why I chose this. However, happy to change it to another version if folks are opinionated here.

[villebro]

This is awesome, thanks @benjreinhart !

[robdiciuccio]

@benjreinhart how is the websocket app configured in the docker-compose workflow? For example, how would I set the jwtSecret value to match what's configured in docker/pythonpath_dev/superset_config_docker.py?

[robdiciuccio]

Seeing consistent redis connection errors when running this locally:

superset_websocket       | [ioredis] Unhandled error event: Error: connect ETIMEDOUT
superset_websocket       |     at TLSSocket.<anonymous> (/home/superset-websocket/node_modules/ioredis/built/redis/index.js:283:31)
superset_websocket       |     at Object.onceWrapper (events.js:421:28)
superset_websocket       |     at TLSSocket.emit (events.js:315:20)
superset_websocket       |     at TLSSocket.Socket._onTimeout (net.js:483:8)
superset_websocket       |     at listOnTimeout (internal/timers.js:554:17)
superset_websocket       |     at processTimers (internal/timers.js:497:7)

But the http://127.0.0.1:8080/health endpoint still returns "OK"

[benjreinhart]

@robdiciuccio it should be the same as non-docker workflow, i.e., adding it to the config.json file.

The redis issue is interesting. docker-compose should be overriding a few values from the config.json file, for example, pointing the redis host to redis (the docker-compose service running redis).

[robdiciuccio]

The redis connection issue was with ssl: true in my config.json, which has now been addressed.