New Dockerfile

[tjstavenger-pnnl]

• Add Dockerfile to run datavoyager (would be nice to get this built and deployed to https://hub.docker.com/)
• Configured server to listen on 0.0.0.0 to open server up for Docker -- this has an artifact of opening other deployements up to all IPs, too
• Added yarn start:headless option to remove the --open parameter as it isn't needed in Docker
• Updated README.md with Docker build & run instructions

While running Travis CI build on my fork to verify my changes didn't break anything tested, I found the build has an out of memory error. I increased the --max-old-space-size to work around the issue.

[domoritz]

Can you use node 12 or 14? Node 6 is not maintained anymore.

[tjstavenger-pnnl]

I picked 6.17.1 as it is what the Travis CI build uses. The newer versions of Node are incompatible with vega/voyager -- at least the builds failed for me. It looks like the voyager code uses removed APIs (likely long past deprecated).

The knock/voyager Dockerfile I based this on had used node 9

[domoritz]

Maybe we should switch to github actions like we did in all other active vega projects.

[tjstavenger-pnnl]

Certainly an option, but I think you'd still need to build with the older version of node until the voyager software is updated. The .travis.yml defines the version of node used, not Travis itself. https://github.com/vega/voyager/blob/master/.travis.yml#L3

[tjstavenger-pnnl]

A quick change to the Dockerfile to use node:latest (presumably 14.4) and it also looks like there are library version incompatibilities. I had tried earlier today to force upgrading all npm libraries to current/latest, but that was unsuccessful too. I hadn't spent the time to dive deeper into the software to determine what versions of each of the dependencies are required. I had really just wanted to get it working, so I fell back to the known working & tested version of 6.17.1.

[domoritz]

Since node 12 is the oldest supported version, let's hold off on merging this pull request.

https://nodejs.org/en/about/releases/

[domoritz]

Would it make sense to use VSCode's container development feature instead? https://code.visualstudio.com/docs/remote/containers

[tjstavenger-pnnl]

I'm not familiar with VSCode's development container feature. It certainly looks interesting.

In my case, my deployment environment requires the Docker container, though I could potentially see the same container reused for development testing & debugging.

[domoritz]

Okay. I'll let @kanitw make the call whether he wants a docker container in master right now. Even if not, it'll be great to have this pull request as a reference if someone wants to use docker.

[tjstavenger-pnnl]

I brought in the same changes from PR #839 to updated node-sass. That lets it build with Node 14.4.0. I also changed the .travis-ci.yml and Dockerfile to use 14.4.0

I didn't change any of the other dependencies -- quite a few are out of date. I took a couple of hours yesterday to try to just update all to the latest and quickly found there are code and dependency incompatibilities. I made it through a few of them, but decided to stop when I got pretty deep into the code. I figure it would be better left to a person more familiar with the code base.