Athens: Publish commit-tagged Docker images

[bndw]

It would be awesome if all commits in master had a corresponding Docker tag.

For example, I'm affected by the bugfix in https://github.com/gomods/athens/commit/ed66d85f3fa7d8cef17aad567c0c3e719e76eba1 but it appears my only option for deploying that fix is to run gomods/athens:canary. There is a :latest tag but that seems to be the latest release, instead of the tip of master.

Suggestion:

• Publish all master commit tags, e.g. gomods/athens:ed66d85f3fa7d8cef17aad567c0c3e719e76eba1
• Publish the tip of master at gomods/athens:latest

For an example of this in the wild, Envoy uses this tagging scheme.

It looks like it'd just take adding a DRONE_COMMIT tag to the docker-latest setup in the drone config to get the per-commit tags. Let me know if that's a contribution you'd like.

[arschles]

@bndw I think this is a great idea!

One modification: would you be open to making the corresponding docker tag the first N (7 is a good choice IMO) characters in the git SHA?

We'd love a PR for this, if you're willing.

[marwan-at-work]

This can end up making our docker hub page look real gigantic in a year or so.

If we actually do release once a month, then the current "canary" version and the latest stable release won't be too far off.

However, if we want to do commit shas, then we should at least have a strategy of cleaning them up and warning the user about commit shas being eventually removed.

[bndw]

That's a good point, it will inflate Dockerhub and unfortunately they still don't have any filtering, search, etc. This may or may not be a UX problem; I think it would come down to documentation.

I just looked at Envoy again and it looks like they've recently split this into two Dockerhub repos, one for releases and one for commits on master.

[marwan-at-work]

@bndw that might be a really good idea. If other maintainers are cool with it, then we can make a gomods/athens-dev

[robjloranger]

gomods/athens-dev has been created

[marwan-at-work]

@robjloranger thank you thank you thank you

[arschles]

late to the game, but 👍 to gomods/athens-dev from me too 😆