Podman fails to pull OCI image with non-http(s):// urls

[ktock]

Is this a BUG REPORT or FEATURE REQUEST? (leave only one on its own line)

/kind bug

Description

Podman fails to pull OCI image with non-http(s):// urls.

Steps to reproduce the issue:
Podman cannot pull the following image (but Docker can).

$ crane manifest ghcr.io/ktock/ubuntu:20.04-i | jq
{
  "schemaVersion": 2,
  "manifests": [
    {
      "mediaType": "application/vnd.oci.image.manifest.v1+json",
      "digest": "sha256:78ef4cff96127a9c9302508ab8116d692e68f863f43598c00aa202ed216d961c",
      "size": 692,
      "urls": [
        "ipfs://bafkreidy55gp7fqspkojgasqrk4bc3ljfzupqy7ugwmmacvcalwsc3mwdq"
      ],
      "platform": {
        "architecture": "amd64",
        "os": "linux"
      }
    }
  ]
}

# podman pull ghcr.io/ktock/ubuntu:20.04-i

Describe the results you received:

# podman pull ghcr.io/ktock/ubuntu:20.04-i
Trying to pull ghcr.io/ktock/ubuntu:20.04-i...
Error: parsing image configuration: Get "ipfs://bafkreiess6chhbdhsl2u6ceapgul46zgvm4e4cbhdi6gwlfgth3vy2qleu": unsupported protocol scheme "ipfs"

Describe the results you expected:

OCI-compliant image should be pulled successfully.

Additional information you deem important (e.g. issue happens only occasionally):

According to OCI Image Spec, non-http(s):// scheme is not prohibited.

urls array of strings

This OPTIONAL property specifies a list of URIs from which this object MAY be downloaded. Each entry MUST conform to RFC 3986. Entries SHOULD use the http and https schemes, as defined in RFC 7230.

(https://github.com/opencontainers/image-spec/blob/v1.0/descriptor.md#properties)

Output of podman version:

Version:      4.0.0-dev
API Version:  4.0.0-dev
Go Version:   go1.16.7
Git Commit:   6d56ac7e0f5109475f22f112f44935866a581144
Built:        Tue Nov  9 02:23:47 2021
OS/Arch:      linux/amd64

Output of podman info --debug:

host:
  arch: amd64
  buildahVersion: 1.23.1
  cgroupControllers:
  - cpuset
  - cpu
  - cpuacct
  - blkio
  - memory
  - devices
  - freezer
  - net_cls
  - perf_event
  - net_prio
  - hugetlb
  - pids
  - rdma
  cgroupManager: cgroupfs
  cgroupVersion: v1
  conmon:
    package: Unknown
    path: /usr/local/bin/conmon
    version: 'conmon version 2.0.26, commit: 0e155c83aa739ef0a0540ec9f9d265f57f68038b'
  cpus: 8
  distribution:
    codename: buster
    distribution: debian
    version: "10"
  eventLogger: file
  hostname: a40a9b93e404
  idMappings:
    gidmap: null
    uidmap: null
  kernel: 5.11.0-37-generic
  linkmode: dynamic
  logDriver: k8s-file
  memFree: 749731840
  memTotal: 16434835456
  ociRuntime:
    name: crun
    package: Unknown
    path: /usr/local/bin/crun
    version: |-
      crun version 0.17
      commit: 0e9229ae34caaebcb86f1fde18de3acaf18c6d9a
      spec: 1.0.0
      +SYSTEMD +SELINUX +APPARMOR +CAP +SECCOMP +EBPF +YAJL
  os: linux
  remoteSocket:
    path: /run/podman/podman.sock
  security:
    apparmorEnabled: false
    capabilities: CAP_AUDIT_WRITE,CAP_CHOWN,CAP_DAC_OVERRIDE,CAP_FOWNER,CAP_FSETID,CAP_KILL,CAP_MKNOD,CAP_NET_BIND_SERVICE,CAP_NET_RAW,CAP_SETFCAP,CAP_SETGID,CAP_SETPCAP,CAP_SETUID,CAP_SYS_CHROOT
    rootless: false
    seccompEnabled: true
    seccompProfilePath: /usr/share/containers/seccomp.json
    selinuxEnabled: false
  serviceIsRemote: false
  slirp4netns:
    executable: ""
    package: ""
    version: ""
  swapFree: 1471909888
  swapTotal: 2147479552
  uptime: 479h 59m 27.7s (Approximately 19.96 days)
plugins:
  log:
  - k8s-file
  - none
  - passthrough
  - journald
  network:
  - bridge
  - macvlan
  - ipvlan
  volume:
  - local
registries: {}
store:
  configFile: /usr/share/containers/storage.conf
  containerStore:
    number: 0
    paused: 0
    running: 0
    stopped: 0
  graphDriverName: overlay
  graphOptions: {}
  graphRoot: /var/lib/containers/storage
  graphStatus:
    Backing Filesystem: extfs
    Native Overlay Diff: "true"
    Supports d_type: "true"
    Using metacopy: "false"
  imageCopyTmpDir: /var/tmp
  imageStore:
    number: 1
  runRoot: /run/containers/storage
  volumePath: /var/lib/containers/storage/volumes
version:
  APIVersion: 4.0.0-dev
  Built: 1636424627
  BuiltTime: Tue Nov  9 02:23:47 2021
  GitCommit: 6d56ac7e0f5109475f22f112f44935866a581144
  GoVersion: go1.16.7
  OsArch: linux/amd64
  Version: 4.0.0-dev

Package info (e.g. output of rpm -q podman or apt list podman):

native build

Have you tested with the latest version of Podman and have you checked the Podman Troubleshooting Guide? (https://github.com/containers/podman/blob/master/troubleshooting.md)

Yes

Additional environment details (AWS, VirtualBox, physical, etc.):

[ktock]

This will be fixed by containers/image#1403.