Ability to specify image tag (for docker pull command) interactively

[Hooverdan96]

Currently, images that rely on the tag for version control (during the docker pull command), require a separate json for each version, as the tag cannot be set up so the user can interactively maintain a value.
As an example, linuxserver provides quite a few repackaged images where the version is explicitly accessible via an environment variable instead of a docker tag (and hence nicely matching with the rockon's current design)

So, it would be nice to maybe have a "pseudo"-environment variable tag that would allow the specification for that. That way, e.g. different Database versions don't require each their own rockon, but can be specified on the fly.

E.g.:
"tag": {
"description": "describe tag format, etc.",
"label": "Docker tag",
"tag_default": "latest",
"index": 1
}
I like the idea of the ability to define defaults for many of these variables, mostly because it will make a "guided user procedure" more easy, even if there are more complex parameters exposed.

But, I know, there are many other priorities :)

[FroggyFlox]

Thanks a lot for taking the time and effort to write this issue @Hooverdan96 !

As mentioned in the linked issue, I completely agree with you and all you described here. The solution you propose is indeed very legible and intuitive from a user perspective. It's also relatively "simple" to implement, I believe.
When I first looked into this, I had something a lot more complex in mind in which we would automatically fetch all available tags from the repository and present these in a drop-down menu to the user. This seemed to be doable if one manages to reliably solve the authentication step (see links below), but it might be too flaky. Using a default value is a must (I agree) and something towards which we'd like to move for all rock-on objects in the future, so that might make this potential flakiness worry moot.
For reference and anyone interested, here are a few links from my notes at the time:

1. https://docs.docker.com/registry/spec/api/#listing-image-tags
2. https://docs.docker.com/registry/spec/auth/token/#how-to-authenticate
3. https://forums.docker.com/t/registry-v2-catalog/45368/3

Altogether, your solution may be our best one, though.