ctr images export and ctr images import are incongruous

[NiklasRosenstein]

Description

Intuitively, one would think that ctr images export followed by a ctr images import should "just work". However, it does not (always).

ctr images export --help implies that, by default, the command does not export the layers for all platforms. However, ctr images import --help suggests that it also doesn't import the layers for all platforms, which seems to me like an implicit --platform=<current_platform>?

$ ctr images export --help
NAME:
   ctr images export - Export images
[ ... ]
OPTIONS:
[ ... ]
   --platform value          Pull content from a specific platform
   --all-platforms           Exports content from all platforms
[ ... ]

$ ctr images import  --help
NAME:
   ctr images import - Import images
[ ... ]
OPTIONS:
   --all-platforms            Imports content for all platforms, false by default
   --platform value           Imports content for specific platform
[ ... ]

Steps to reproduce the issue

$ ctr images pull docker.io/library/busybox:latest
$ctr images export out.tar docker.io/library/busybox:latest
$ ctr images import out.tar
ctr: content digest sha256:b67a20380506da97caef06b5c957d548fe854443c773b0e3d0e21313190beec9: not found
$ ctr images import out.tar  --platform=linux/amd64
unpacking docker.io/library/busybox:latest (sha256:c3839dd800b9eb7603340509769c43e146a74c63dca3045a8e7dc8ee07e53966)...done

One must specify the --platform option for this to work, and the error message when it does not is anything but helpful to figure out the solution.

Describe the results you received and expected

I expect that ctr images import-ing an archive exported with ctr images export works with symmetrical flags in any case (here: no --platform on either side).

What version of containerd are you using?

containerd github.com/containerd/containerd 1.7.2

Any other relevant information

No response

Show configuration if it is related to CRI plugin.

No response

[ja-pavi]

Hi! I'm a UT Austin CS student working on a final project in my virtualization course where we have to contribute to an open source project. I was wondering I could get this issue assigned to me?

[dcantah]

@ja-pavi Done

[drriguz]

Same issue here, I export and then import and got error says that content not found.
However, I cannot figure out what exactly is missing.
Adding --platform=linux/amd64 did solve my problem.