allow multiple images pull

[michelpromonet]

Hi,

Please find this PR that intend to pull multiple images and save it to a tar file that could be loaded by docker load.

It is a quick & dirty try, let me know if you think this feature extension is interesting or if there is an other way to do this with the cli.

Best Regards,
Michel.

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[google-cla]

Thanks for your pull request. It looks like this may be your first contribution to a Google open source project (if not, look below for help). Before we can look at your pull request, you'll need to sign a Contributor License Agreement (CLA).

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[michelpromonet]

@googlebot I signed it!

[jonjohnsonjr]

Thanks for the PR!

It is a quick & dirty try, let me know if you think this feature extension is interesting or if there is an other way to do this with the cli.

Definitely interesting and something I'd like to support. CLI UX looks good to me, but I'm a little reluctant to modify the signature for crane.Save etc.

Do you mind instead adding three new functions?

• crane.MultiSave
• crane.MultiSaveLegacy
• crane.MultiSaveOCI

Then we can rewrite Save{Legacy,OCI} as trivial implementations that just call into MultiSave... without breaking anything that depends on the Save functions today.

[jonjohnsonjr]

LGTM beyond a couple small nits.

Can you also add godoc comments to the Multi funcs?

[codecov-io]

Codecov Report

Merging #975 (7b7d5e8) into main (a11b12f) will decrease coverage by 0.16%.
The diff coverage is 75.00%.

❗ Current head 7b7d5e8 differs from pull request most recent head 934a314. Consider uploading reports for the commit 934a314 to get more accurate results

@@            Coverage Diff             @@
##             main     #975      +/-   ##
==========================================
- Coverage   74.75%   74.59%   -0.17%     
==========================================
  Files         107      107              
  Lines        5007     5022      +15     
==========================================
+ Hits         3743     3746       +3     
- Misses        710      721      +11     
- Partials      554      555       +1     

Impacted Files	Coverage Δ
pkg/crane/pull.go	71.42% <75.00%> (-22.69%)	⬇️

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[michelpromonet]

Hi jonjohnsonjr,

Please find update adding comment on MultiWrite method and rework on MultiWriteOCI.

Best Regards,
Michel.

[jonjohnsonjr]

LGTM, thanks!