Add support for COPY --exclude and ADD --exclude options

[rhatdan]

Fixes: #5678

What type of PR is this?

/kind api-change
/kind bug
/kind cleanup
/kind deprecation
/kind design
/kind documentation
/kind failing-test
/kind feature
/kind flake
/kind other

What this PR does / why we need it:

How to verify it

Which issue(s) this PR fixes:

Special notes for your reviewer:

Does this PR introduce a user-facing change?

COPY option  and buildah copy now support --exclude options.

[rhatdan]

@flouthoc @giuseppe @nalind @mheon PTAL

[rhatdan]

@slinkydeveloper PTAL

[rhatdan]

@nalind @flouthoc @giuseppe @TomSweeneyRedHat @lsm5 @mheon PTAL

[flouthoc]

LGTM

[nalind]

This needs quite a few more tests to ensure that we're getting this right. Add conformance tests using multiple ways of expressing the sources to be copied (".", "/", "*"), and tests that combine COPY or ADD using --exclude with an ignorefile, including cases where they disagree on whether or not a particular item should or should not be excluded.

[rhatdan]

One issue is docker does not support --exclude in conformance-test right now.

[nalind]

Set dockerUseBuildKit in the test case to have the client set the right flag in its request to the REST API's build endpoint. I'm not 100% sure that excludes are handled correctly between the client and the daemon and between the daemon and buildkit, but then maybe the odd things I'm seeing are somehow specific to my system.

[TomSweeneyRedHat]

LGTM once comments are addressed and tests are hip

[villesau]

Is there timeline for landing this? 👀

[rhatdan]

@villesau I have been working on other tools, have not come back to change the code that @nalind suggests.

If you want to try to change it go for it.

The actual code is ready to go, the tests are just a little broken.

[villesau]

@rhatdan Are there some instructions how to set this up and run the tests? I might try, but please do not count on it 😅

[nalind]

(Turns out I was mistaken, and quoting does work for the value of the --exclude= argument.)

[giuseppe]

LGTM

[openshift-ci]

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This pull-request has been approved by: flouthoc, giuseppe, rhatdan

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