How to get information from ghcr Docker Registry HTTP API V2 with curl

ghcr.sh

#!/usr/bin/env bash
# ref: https://git.521000.bestmunity/t/how-to-check-if-a-container-image-exists-on-ghcr/154836/3

# public image's {USER}/{IMAGE}
USER_IMAGE=eggplants/asciiquarium-docker

# get token ('{"token":"***"}' -> '***')
TOKEN="$(
  curl "https://ghcr.io/token?scope=repository:${USER_IMAGE}:pull" |
  awk -F'"' '$0=$4'
)"

_curl(){ curl -H "Authorization: Bearer ${TOKEN}" "$1" }

# get tags
_curl "https://ghcr.io/v2/${USER_IMAGE}/tags/list"

# get manifest of the latest image
_curl "https://ghcr.io/v2/${USER_IMAGE}/manifests/latest"

manifest.json

{
   "mediaType": "application/vnd.docker.distribution.manifest.v2+json",
   "schemaVersion": 2,
   "config": {
      "mediaType": "application/vnd.docker.container.image.v1+json",
      "digest": "sha256:fb4552eacdc8e01082f87bae6a0fec6e1b61630f0a1e5a0e6a699d05ff0337fd",
      "size": 5551
   },
   "layers": [
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "digest": "sha256:4be315f6562fccf08fd6c749557e31e45ab6d987370e20e2c4933ddb04ddd5ff",
         "size": 27140664
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "digest": "sha256:f6722131500bb303e9a66464a1d7a3805efaa2db3715d5204f5bdb89656a0589",
         "size": 200
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "digest": "sha256:ac65630ca76f500df10c4676ec0fe8623070f1ab3394b8c2f4c6db4a48ebfa6c",
         "size": 14894913
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "digest": "sha256:380348d1c396f3eb3c542ccc62b73383297b6a48b625f9671f59c109d964954e",
         "size": 43915124
      },
      {
         "mediaType": "application/vnd.docker.image.rootfs.diff.tar.gzip",
         "digest": "sha256:49470ea4d7663bcafd377eeeeda4d15445b09043f2dbf7d5f2865a66fbadcc44",
         "size": 604613
      }
   ]
}

tags.json

{"name":"eggplants/asciiquarium-docker","tags":["0.0.0","0.0","latest"]}

Didn't know how to extract info from the ghcr registry, your script is a good documentation, thanks!

@mtovmassian If you are pythonista, it could be useful.
https://github.com/eggplants/ghcr-badge/blob/master/ghcr_badge/generate.py

Hi @eggplants This script is super helpful, but I’m having a bit of trouble getting the manifest digest from GHCR. GHCR only seems to respond to the digest of each artifact, but DockerHub can give me the manifest digest of the repo without a token. Do you know why? Or did I do something wrong?