Bug 1919032: Fix image extract from Root Directory

[zerodayz]

This patch adds possibility to extract file from the root directory of an image.

Closes: BZ#1919032

[openshift-ci-robot]

@zerodayz: This pull request references Bugzilla bug 1919032, which is invalid:

• expected the bug to target the "4.7.0" release, but it targets "---" instead

Comment /bugzilla refresh to re-evaluate validity if changes to the Bugzilla bug are made, or edit the title of this pull request to link to a different bug.

In response to this:

Bug 1919032: Fix image extract from Root Directory

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[zerodayz]

/test e2e-agnostic-cmd

[soltysh]

/assign @sallyom

[soltysh]

/bugzilla refresh

[openshift-ci-robot]

@soltysh: This pull request references Bugzilla bug 1919032, which is valid. The bug has been moved to the POST state.

3 validation(s) were run on this bug

• bug is open, matching expected state (open)
• bug target release (4.7.0) matches configured target release for branch (4.7.0)
• bug is in the state NEW, which is one of the valid states (NEW, ASSIGNED, ON_DEV, POST, POST)

In response to this:

/bugzilla refresh

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[zerodayz]

the problem is that when only file is being a source for example /help.1, the directory "parent" is "." and it was excluded because of the name == "." || parent == ".".

Even fixing this was not enough since tar doesn't consider /. meaning the root directory is omited, for example:
usr/lib/ instead of /usr/lib.

Hence adding new functions. I am unsure about the case/switch that can be further improved. Any feedback welcome @sallyom Let me know.

[sallyom]

I see this PR fixes the bug, great!! Sharing to enable easy verifying:

$ touch hello
$ container=$(buildah from alpine)
$ buildah copy $container hello /hello
$ buildah commit --format docker $container localhost:5000/alpine:new
$ podman push localhost:5000/alpine:new
$ mkdir ext; cd ext
$ oc image extract localhost:5000/alpine:new --file /hello
$ ls
hello
$ rm hello && oc image extract localhost:5000/alpine:new --path /hello:/tmp/ext 
$ ls
hello

and for non root-dir extract:

$ touch hello-hello
$ container=$(buildah from alpine)
$ buildah copy $container hello /tmp/hello-hello
$ buildah commit --format docker $container localhost:5000/alpine:new-new
$ podman push localhost:5000/alpine:new-new
$ mkdir ext; cd ext
$ oc image extract localhost:5000/alpine:new --file /tmp/hello-hello
$ ls
hello-hello

[zerodayz]

/retest

[zerodayz]

/retest

[soltysh]

/approve
@sallyom owns the final tag

[sallyom]

@zerodayz I made a note in the file to fix the Alter fn. Also, you'll need to run
make update-gofmt (or gofmt -w -s pkg/cli/image/extract/extract.go) Then all looking good, thank you!

[zerodayz]

/retest

[zerodayz]

/retest

[zerodayz]

/test e2e-agnostic-cmd

[zerodayz]

/test e2e-agnostic-cmd

[soltysh]

This test should be fixed now
/test e2e-agnostic-cmd

[zerodayz]

/test e2e-agnostic-cmd

[zerodayz]

/cc @sallyom All tests are passing, would you be able to review again? Thanks!

[sallyom]

/lgtm

[openshift-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sallyom, soltysh, zerodayz

The full list of commands accepted by this bot can be found here.

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Needs approval from an approver in each of these files:

• OWNERS [soltysh]

Approvers can indicate their approval by writing /approve in a comment
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[openshift-ci-robot]

@zerodayz: All pull requests linked via external trackers have merged:

• openshift/oc#713

Bugzilla bug 1919032 has been moved to the MODIFIED state.

In response to this:

Bug 1919032: Fix image extract from Root Directory

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

[smarterclayton]

Changes like these need unit tests. I’d like to see a set added that verify the streamed function receives the correct files from a set of generated fake images before we allow more changes like this to these commands.

[soltysh]

@zerodayz can you prepare tests ensuring this is working as designed in a followup?

[zerodayz]

@soltysh @smarterclayton Will work on unit tests today. My bad apologies.

[zerodayz]

@soltysh @smarterclayton @sallyom I started putting together Unit tests for image extract in #736

It seems that there are no unit tests at all for image extract. So I am putting it together now, not just the extracting image, but parsing and other functions.