Support custom labels in wave-api

[munishchouhan]

This PR will add labels in SubmitContainerTokenRequest class, so that it can be added in spack and conda docker file

[pditommaso]

Umm should it be a List of pairs or Map of key-value ? a list would allow repetitions. Is this possible with docker labels?

[munishchouhan]

If there is a repeated label, but with a different value then the latest value will be applied, so i think we can use Map here

[munishchouhan]

@pditommaso @marcodelapierre please review

[marcodelapierre]

Looks good to me, thanks @munishchouhan , will confirm after reviewing the other related PRs.

[marcodelapierre]

see minor requests - thank you Munish

[marcodelapierre]

@munishchouhan what do you think if we modelled labels as List instead of Map?

In the end, this would be the same approach adopted for the environment variables, i.e. env attribute; the two attributes look very similar to me. And then implementation of labels in Wave could closely mimick that of env.

What do you think?

See commit 618b846

[munishchouhan]

@munishchouhan what do you think if we modelled labels as List instead of Map?

In the end, this would be the same approach adopted for the environment variables, i.e. env attribute; the two attributes look very similar to me. And then implementation of labels in Wave could closely mimick that of env.

What do you think?

See commit 618b846

Map is used because the list will allow repetitions
check this comment #18 (comment)

[marcodelapierre]

Thanks for pointing out Munish, had overlooked that comment.
I see that Docker does work with multiple definitions of a same LABEL, by retaining the most recent one, a bit like environment variables definition in a Linux shell. As such, a List would have worked as well (same as it works for env variables).

This being said, I like your latest implementation, where the List is converted to Map only in the Wave server - it keeps the implementation of the functionality simple for API and clients. I ultimately don't see big drawbacks of using the Map there, so I am leaving to you the ultimate decision.

@pditommaso this Libseqera PR is ready for merging.