Migrate Vagrant -> Docker

[vlsi]

Docker images could probably be reused in Apache CI for Calcite.

[michaelmior]

I'm up for taking this on if no one else is strongly interested in doing so.

[julianhyde]

For what it's worth, I asked some questions on druid-dev and several people suggested docker. By that time I had invested effort in vagrant. We wouldn't be able to use docker off-the-shelf because we load the extra foodmart data set. But their VM settings may be useful.

See Absolute minimal Druid cluster.

[michaelmior]

@julianhyde I don't see why we couldn't use it off-the-shelf. You can always mount local files as volumes in Docker containers.

[julianhyde]

Getting the software is easy. The hard part is loading the data (i.e. starting an indexing task). The off-the-shelf version doesn't have the data.

[michaelmior]

I understand. What I am saying is that if the data is in a local folder, that folder can just be made available to the container without having to change the Docker image. That said, there's nothing wrong with adding a couple extra layers to the container if necessary.

[michaelmior]

FYI as far as OS X support goes, looks like the Docker version using the OS X Hypervisor Framework is getting good reviews.

[michaelmior]

Are people still open to exploring this direction? @julianhyde @vlsi

I'd be interested in doing some of the work on this, but it would be nice to know if this is a direction everyone is comfortable with pursuing. It would also be helpful to get some idea of the current CI setup for integration testing to know what work might need to be done on that side.

[julianhyde]

I don't feel strongly about it. The VM is working fine for my purposes (albeit using a little more memory than I'd like, due to Druid) but moving to Docker sounds like an improvement and I wouldn't object.

[michaelmior]

@julianhyde My concern is that we've already experienced OOM issues and we're continuing to add new adapters so this problem is only going to get worse. I've already resorted to using Docker for Cassandra since I can run with significantly less memory on my slightly aged laptop.

[julianhyde]

I feel your pain. I can use the VM on my new laptop with 8GB RAM but it was not possible on my old laptop with 4GB RAM.