Support podman in tasks/build.rake

[gregorynisbet-google]

Support podman in addition to docker in tasks/build.rake via the DOCKER environment variable.

Pull Request (PR) description

I did the simplest thing I could think of to make DOCKER=podman rake vox:build succeed.

There are a few differences between --format json for Docker and podman, but I still think
that that's the most robust way to get the commands to emit structured output.

I'm curious whether folks think this is worth doing at all, and whether an environment variable
is the best way of achieving this (and also whether shell substitution is better than doing the
conditional at the ruby level)

This Pull Request (PR) fixes the following issues

n/a

[Sharpie]

I opened #228 before I noticed this PR. The approach there is even simpler, but requires the use of the podman-docker shim package to re-direct the docker CLI to podman.

Building other OpenVox components, such as openvox-agent and openbolt, under Podman requires the use of podman-docker unless some enhancement is done to Vanagon.

[gregorynisbet-google]

No worries. Any interest in me reworking this to remove the dependency on the shim?

[Sharpie]

Using environment variables to pick a CLI implementation seems reasonable to me. Perhaps DOCKER_BIN or DOCKER_CLI instead of DOCKER as the shorter variable is sometimes used to flag whether or not a process is running in a containerized environment.

[Sharpie]

Looks good to me 👍

Thanks for the contribution!

[gregorynisbet-google]

Hi, so I can keep the PR up to date with respect to main (which I did just now with a force push), but I don't know the procedure for actually merging the PR.

Auto-merge was enabled prior to my last push, but I wasn't able to merge it at that time. Is two committers' approval needed for a PR to be merged?

[bastelfreak]

@gregorynisbet-google sorry for the delay here! I would like to get this merged, but run into some issues. The rake task fails with:

Retrieving me/raynes/conch/0.8.0/conch-0.8.0.jar from clojars
Retrieving org/flatland/useful/0.10.6/useful-0.10.6.jar from clojars
Retrieving org/openvoxproject/typesafe-config/1.0.3/typesafe-config-1.0.3.jar from clojars
Copying lein-ezbake resources from /root/.m2/repository/org/openvoxproject/lein-ezbake/2.7.7/lein-ezbake-2.7.7.jar to tmp/ezbake-resources
Error encountered performing task 'ezbake' with profile(s): 'user,ezbake,provided'
java.io.FileNotFoundException: /code/tmp/ezbake-resources/puppetlabs/lein-ezbake/template/global/ext/ezbake.tmpfiles.conf.erb (Permission denied)

Did you run the podman service as user service or as root?

[gregorynisbet-google]

I'm running it rootless, which is the default out of the box on my platform.

For me, at least, running DOCKER_BIN=podman rake vox:build works locally.

I'm not sure what could cause this PR to fail with some kind of permission issue when run in CI (or locally) in an environment where DOCKER_BIN is not set.

The only thing I can think of is some change to the behavior of the build system when passing the format argument to docker images, so I split off that part of the PR here (#332).