change --pull to be consistent with podman

[QiWang19]

change --pull for bud and from to be consistent with podman change containers/podman#3617

Signed-off-by: Qi Wang [email protected]

[rhatdan]

Combine these together with the next section

if pullType == buildahcli.PullImageAlways || iopts.PullAlways {
pullPolicy = imagebuildah.PullAlways
}

[rhatdan]

Please hide the pullalways code and remove it from man pages.
Also throw an error if the user says to --pull-always and --pull does not match.

[rhatdan]

This is a breaking change.
If I previously had the script below, it will now break.

[rhatdan]

This is a change. The --pull used to mean to look at the registry and pull if newer. Now that is not an option, as I understand it.
Should their be another option "newer", which should be default and pull a newer image if it exists at the registy otherwise use local.

[QiWang19]

If current boolean --pull also for pulling the newer image, I need to figure out to prevent buildah from pulling new image when --pull missing the image exists locally but has a newer version in the registry.

[QiWang19]

Does buildah --pull can pull the newer image and replace the old one in the local? I tried the master buildah didn't see the update and didn't find the code implemented this functionality.
@TomSweeneyRedHat Do you know which PR I can refer to for finding newer version image from registry?

[TomSweeneyRedHat]

buildah bud --pull is supposed to pull the image if it doesn't exist locally or if the version on the registry is newer there than the version stored locally. I've not tested it recently to verify that it does do that.

Where it happens is fun to find.

https://github.com/containers/buildah/blob/master/new.go#L100 is where resolveImage() is called and the check happens here: https://github.com/containers/buildah/blob/master/new.go#L140

Or at least that's the theory.

[QiWang19]

thanks, @TomSweeneyRedHat but not code there, that code is for --pull-always.
if bud --pull, buildah will set options.PullPolicy = PullIfMissing, but https://github.com/containers/buildah/blob/master/new.go#L140 is inside the if options.PullPolicy == PullAlways

[rhatdan]

This is a breaking change:

$ buildah from --pull fedora
fedora-working-container-11

Currently this is legal

$ ./buildah from --pull fedora
an image name (or "scratch") must be specified
ERRO exit status 1                                

With your change, it breaks.

[QiWang19]

--pull was changed to string, so buildah from --pull fedora fails because no arg.
can we cheat and make --pull work both as boolean and string? I don't know how to make it.

[rhatdan]

@baude Any ideas? How much hacking would it take to see that fedora was not a valid string and switch it to a missing option.

[rh-atomic-bot]

☔ The latest upstream changes (presumably 5671417) made this pull request unmergeable. Please resolve the merge conflicts.

[rhatdan]

@QiWang19 is this still being worked on, or has it been supplanted by @TomSweeneyRedHat PR #1873

[QiWang19]

I'm not working on this. This PR change --pull from bool to string. This is a breaking change and I don't know how to make --pull work both as boolean and string.

[rhatdan]

Lets get #1873 in and then we can discuss this.