RFC for exporting images in parallel

[ESWZY]

We already have some discussion here: lifecycle#1167.

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[jjbustamante]

Hi @ESWZY!

Thank you so much for working on this proposal and the RFC it is really awesome!

My suggestions:

• Add to the what is this section the propose flag to the exporter that will enable the feature. Usually we just add a table, similar to the one in the spec, with the new flag we want to incorporate.
• Once you have the flag, in the how it works section, you can just add a few examples of invocations of the exporter with the new flag and you can explain the expected outcome and behavior.

The new flags, at the end, will require a new API spec, so you can also put them under the Spec. Changes section, but that is something can be done later once you get consensus from the community around the feature.

[ESWZY]

Hi @ESWZY!

Thank you so much for working on this proposal and the RFC it is really awesome!

My suggestions:

• Add to the what is this section the propose flag to the exporter that will enable the feature. Usually we just add a table, similar to the one in the spec, with the new flag we want to incorporate.
• Once you have the flag, in the how it works section, you can just add a few examples of invocations of the exporter with the new flag and you can explain the expected outcome and behavior.

The new flags, at the end, will require a new API spec, so you can also put them under the Spec. Changes section, but that is something can be done later once you get consensus from the community around the feature.

Thanks for your suggestion!

I added a proposal flag to this PRC and made a preliminary attempt in lifecycle#1167.

[jjbustamante]

I would suggest adding a WARN message to the end-user to indicate that using the parallel flag without exporting a cache image has no effect.

[ESWZY]

This makes sense, I agree with you.

[jjbustamante]

From my point of view:

• How to allow users to choose the export method? environment variable? Or a parameter of the creator?
  I like how you are proposing it, with the flag the env variable

• Does it also need to be specified in the pack tool?
  Probably, once we get the RFC approved, we can create the issue on pack to expose the behavior for end-users

• Should this feature be enabled by default?
  I'd say no to avoid unexpected behaviors to people consuming the lifecycle.

[jjbustamante]

Awesome work @ESWZY! I really like this RFC

[natalieparellano]

Suggestion from working group - when these flags are combined in the creator, -parallel-export might make more sense. However -parallel-export might look funny as a flag to the exporter.

Perhaps -parallel-export as a flag to the creator and -parallel as a flag to the exporter? I don't have a strong opinion either way, but thought I'd surface this idea.

[natalieparellano]

@ESWZY @jabrown85 perhaps you could opine here? Then I'll move this one back into voting. We already have enough approvals.

[ESWZY]

At first I wanted to use this name, but I saw that the other flags were very short, so I chose a similar format.

But I think an informative name is very helpful for those who are new to this field.

[ESWZY]

I think both are OK, as long as one can understand the meaning of this field by reading help messages.

[natalieparellano]

Moved to voting, as this is a sub-team RFC and has approvals from both implementation maintainers I think we can merge it early cc @jabrown85