Adopt wider Docker tagging model (eg 3, 3.2, 3.2.1)

[arm4b]

Releasing st2 v3.2.1 should lead to Docker Hub deployment for the following docker tags: 3, 3.2, 3.2.1 which is a common practice.

This way someone could rely on a wider version interval or pin to specific st2 version depending on their needs.

More info:

• https://github.com/StackStorm/st2-docker/blob/2c2032595a03394b56fbf9cc16114d823a540471/VERSIONING.md
• Version tagging st2-docker#78
• https://github.com/StackStorm/st2-docker/blob/2c2032595a03394b56fbf9cc16114d823a540471/bin/common.sh
• https://github.com/StackStorm/st2-docker/blob/2c2032595a03394b56fbf9cc16114d823a540471/bin/deploy.sh
• https://github.com/StackStorm/st2-docker/blob/2c2032595a03394b56fbf9cc16114d823a540471/bin/gatekeeper.sh

[Sheshagiri]

@armab thinking out loud here

Releasing st2 v3.2.1 should lead to Docker Hub deployment for the following docker tags: 3, 3.2, 3.2.1 which is a common practice.

This sounds like an anti-pattern to retrospectively update the previous releases. For example, if I pinned my deployment to 3.2, based on what you are proposing my deployment would automatically pull(if enabled) the updated docker image of 3.2 when 3.2.1 is released.

Some users might want to stay at a particular release.

[arm4b]

We don't update previous releases. If 3.2.1 is relased, we don't update 3.2.0 in any way.
If users want to stay on particular release, they can pin to 3.2.1 or 3.2.0 explicitly. That remains traditional.

However

• 3.2 Docker tag includes potential patches like 3.2.1, 3.2.2 automatically, but not 3.3
• 3 Docker tag allows users to rely on latest version in the 3.x.x: is it 3.2.0, 3.2.1 or 3.3.0, but not 4.x.x

This model is very helpful and widely used between the official Docker images, ex: https://hub.docker.com/_/nginx?tab=tags

[Sheshagiri]

Okay, got you. It’s a lot clear now, nice write up.

[winem]

Hi,

I'm happy to do this and I have a working solution already.

I just have a question regarding the requirements: Do we want to apply the logic only for actual st2 releases or also for 3.4dev for example? We could have something like 3dev and 3.4dev (and 3.4.0dev if we use branches for patches) but I'm not sure if that's needed. For now I'd just apply the tags that do not match the ST2_VERSION or DOCKER_TAG if the ST2_VERSION is a release and does not have the dev suffix.

Let me know what you think and you'll have a PR soon. :)

[arm4b]

Thanks for looking at this!

There is no need for dev.
Check https://github.com/StackStorm/st2-docker/blob/2c2032595a03394b56fbf9cc16114d823a540471/VERSIONING.md which explains the logic in full.

Also side note, we want to push latest tag, making sure it's always referring to the latest stable st2 version, per #35.

[winem]

Thanks for the feedback. Will provide the PR now.

And thanks for the hint with the latest tag. I have that already on my list and will provide another PR once this one got merged. Have to do a little bit of research before providing the PR.