buildah fails when REGISTRY_AUTH_FILE doesn't exist

[rcny]

Hello!

Setting REGISTRY_AUTH_FILE to a non-existent file will result in buildah failing to operate with public registries:

[root@dd836c415cc3 /]# env REGISTRY_AUTH_FILE=/tmp/non_existent_creds.json buildah pull docker.io/library/hello-world
error checking authfile path /tmp/non_existent_creds.json: stat /tmp/non_existent_creds.json: no such file or directory

Is this a feature or a bug?

Currently I resolve it with e.g. env REGISTRY_AUTH_FILE= buildah pull docker.io/library/hello-world for specific commands. Can't remove REGISTRY_AUTH_FILE at all because of #3216.

Running 1.20.1 from current quay.io/buildah/stable image.

[rhatdan]

I am thinking this is a bug.

We should only check for the existence of the authfile if the user specifies it.

[vrothberg]

I consider setting the env var as user-specified input (i.e., the counterpart of --authfile).

[rhatdan]

The thing is we do not need to fail until the user actually attempts to use the file, in that case.

[rhatdan]

For example the use case that this user was hitting was having it set within a container image, and only used when needed. We would fail all the time.

[TriplEight]

I'm having the same issue with buildah logout, even when it wasn't logged in anywhere:

buildah logout --all
error checking authfile path /tmp/registry_auth.json: stat /tmp/registry_auth.json: no such file or directory

[TriplEight]

and with the workaround I'm getting the other misleading output:

env REGISTRY_AUTH_FILE= buildah logout docker.io
Not logged into docker.io

[rhatdan]

Why is this misleading?

[TomSweeneyRedHat]

I think the logout error is misleading as it doesn't indicate that the file doesn't exist. From reading the message, I'd think the authfile existed, I just didn't have an entry in the authfile.

[rhatdan]

We treat REGISTRY_AUTH_FILE="" the same as we do not being set at all.