hello-world and hello-world@sha256:... are treated as different images

[AkihiroSuda]

Description

hello-world and hello-world@sha256:... are treated as different images

Steps to reproduce the issue

$ nerdctl pull hello-world
docker.io/library/hello-world:latest:                                             resolved       |++++++++++++++++++++++++++++++++++++++| 
index-sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb:    done           |++++++++++++++++++++++++++++++++++++++| 
manifest-sha256:f54a58bc1aac5ea1a25d796ae155dc228b3f0e11d046ae276b39c4bf2f13d8c4: done           |++++++++++++++++++++++++++++++++++++++| 
config-sha256:feb5d9fea6a5e9606aa995e879d862b825965ba48de054caab5ef356dc6b3412:   done           |++++++++++++++++++++++++++++++++++++++| 
layer-sha256:2db29710123e3e53a794f2694094b9b4338aa9ee5c40b930cb8063a1be392c54:    done           |++++++++++++++++++++++++++++++++++++++| 
elapsed: 5.3 s 

$ nerdctl image inspect hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb
FATA[0000] 1 errors:
no such image: hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb

$ nerdctl pull hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb
docker.io/library/hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb: resolved       |++++++++++++++++++++++++++++++++++++++| 
index-sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb:                         done           |++++++++++++++++++++++++++++++++++++++| 
manifest-sha256:f54a58bc1aac5ea1a25d796ae155dc228b3f0e11d046ae276b39c4bf2f13d8c4:                      done           |++++++++++++++++++++++++++++++++++++++| 
config-sha256:feb5d9fea6a5e9606aa995e879d862b825965ba48de054caab5ef356dc6b3412:                        done           |++++++++++++++++++++++++++++++++++++++| 
elapsed: 1.9 s                                                                                         total:   0.0 B (0.0 B/s)

$ nerdctl image inspect hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb
[
    {
        "Id": "sha256:feb5d9fea6a5e9606aa995e879d862b825965ba48de054caab5ef356dc6b3412",
        "RepoTags": [
            "hello-world:"
        ],
        "RepoDigests": [
            "hello-world@sha256:6e8b6f026e0b9c419ea0fd02d3905dd0952ad1feea67543f525c73a0a790fefb"
        ],
        "Comment": "",
        "Created": "2021-09-23T23:47:57.442225064Z",
        "Author": "",
        "Config": {
            "AttachStdin": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
            ],
            "Cmd": [
                "/hello"
            ]
        },
        "Architecture": "amd64",
        "Os": "linux",
        "RootFS": {
            "Type": "layers",
            "Layers": [
                "sha256:e07ee1baac5fae6a26f30cabfe54a36d3402f96afda318fe0a96cec4ca393359"
            ]
        },
        "Metadata": {
            "LastTagTime": "0001-01-01T00:00:00Z"
        }
    }
]

$ nerdctl images
REPOSITORY     TAG       IMAGE ID        CREATED               PLATFORM       SIZE        BLOB SIZE
hello-world    latest    6e8b6f026e0b    2 minutes ago         linux/amd64    20.0 KiB    6.9 KiB
hello-world    <none>    6e8b6f026e0b    About a minute ago    linux/amd64    20.0 KiB    6.9 KiB

Describe the results you received and expected

Received: hello-world and hello-world@sha256:... are treated as different images
Expected: should be treated as a single image

What version of nerdctl are you using?

v1.2.1

Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

Host information

No response

[suyanhanx]

#1802 It looks related to this issue.

[ginglis13]

It looks like pull calls EnsureImage with "always" option:

nerdctl/pkg/cmd/image/pull.go

Line 50 in 8f2cad4

_, err = EnsureImage(ctx, client, rawRef, ocispecPlatforms, "always", unpack, options.Quiet, options)

which will ignore a check for existing image:

nerdctl/pkg/imgutil/imgutil.go

Lines 114 to 117 in 8f2cad4

	// if not `always` pull and given one platform and image found locally, return existing image directly.
	if mode != "always" && len(ocispecPlatforms) == 1 {
	if res, err := GetExistingImage(ctx, client, snapshotter, rawRef, ocispecPlatforms[0]); err == nil {
	return res, nil

what is meant by the PullMode values "always", "missing", and "never"?

nerdctl/pkg/imgutil/imgutil.go

Lines 54 to 55 in 8f2cad4

	// PullMode is either one of "always", "missing", "never"
	type PullMode = string