when tag IPv6 registry url, report "invalid reference format"

[kycheng]

Description

I want to push the image to a pure IPv6 registry. I use the rename image and find an error.

Steps to reproduce the issue:

1. A registry of IPv6 addresses
2. Use buildah tag busybox: buildah tag busybox '[2008::192:168:131:145]:30008/test/busybox:latest'

Describe the results you received:

error adding names [[2008::192:168:131:145]:30008/test/busybox:latest] to image "busybox": error parsing name "[2008::192:168:131:145]:30008/test/busybox:latest": error parsing image name "[2008::192:168:131:145]:30008/test/busybox:latest": invalid reference format

Output of rpm -q buildah or apt list buildah:

buildah-1.11.6-11.el7_8.x86_64

Output of buildah version:

Version:         1.11.6
Go Version:      go1.12.12
Image Spec:      1.0.1-dev
Runtime Spec:    1.0.1-dev
CNI Spec:        0.4.0
libcni Version:
image Version:   5.0.0
Git Commit:
Built:           Thu Jan  1 08:00:00 1970
OS/Arch:         linux/amd64

I found a similar issue in docker, it seems that this is a general problem, does buildah plan to support IPv6 address resolution?

moby/moby#39033

[flouthoc]

I think porting distribution/distribution#3489 to c/image should fix this, but just curious why is c/image not using regexp directly from distribution.

@mtrmac @vrothberg any idea about why c/image is not directly using distribution ?

[mtrmac]

Adding that syntax immediately directly conflicts with the containers-storage: syntax for [various options]reference.

So we can’t just start accepting that syntax without significant other work. (Maybe we can write a parser that unambiguously decides whether […] is an IPv6 address or options. I don’t know. Or maybe we need to invent some completely new syntax :/ .)

Also consider the risk of all the various hand-rolled parsers, in many shell scripts or possibly in the Podman codebase, just looking for : to get a tag or digest. I’ve been on a long crusade to replace substring searches with correct parsing, but I don’t have any illusions that I’ve been 100% successful even in just the Podman codebase, let alone outside code over which we have no control.

So, defining a new syntax that uses : for other purposes is, strictly speaking, always possible, but in practice fairly likely to break something.

Pragmatically, as years go by without having support for raw IPv6 addresses, it gets easier to argue that adding support for raw IPv6 addresses is not that necessary.

[kycheng]

Pragmatically, as years go by without having support for raw IPv6 addresses, it gets easier to argue that adding support for raw IPv6 addresses is not that necessary.

when IPv4 addresses are exhausted, in the era when IPv6 is more popular, it is valuable to use the original IPv6 addresses to build a registry.

I think we are in a period of transition.

[rhatdan]

<snarky>A transition going on 30 years</snarky>

[github-actions[bot]]

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