This script can be used to copy all docker images from one GitLab-project to another. It was created because in GitLab it's not possible to move projects that contain docker images.

copy_images.sh

#!/usr/bin/env bash

# This script can be used to copy all docker images from one GitLab-project to another. 
# It was created because in GitLab it's not possible to move projects that contain docker images.
#
# Related issue: https://gitlab.com/gitlab-org/gitlab/-/issues/18383
#
# Author: Daniel Estermann <estermad@apache.org>
# Thanks to komar <komar@core.org.ua> for his brilliant support

ME=$(basename "$0")
DEPENDS="docker curl jq tac"

die() {
  if [[ "$*" && -t 2 ]]; then
    printf "\e[31;1m%s\e[0m\n" "$*" >&2
  else
    printf "%s\n" "$*" >&2
  fi
  exit 1
}

usage() {
  cat <<- EOM
		Usage: $ME <gitlab-server> <path-to-project> <new-path-to-project>

		Example: $ME gitlab.com johndoe/foo johndoe/bar
	EOM
  exit 1
}

[[ ${GITLAB_TOKEN} ]] || die "Please provide an access token via the environment variable GITLAB_TOKEN"

for CMD in $DEPENDS; do
  command -v $CMD >/dev/null 2>&1 || die "This script requires $CMD but it's not installed. Aborting."
done

docker ps >/dev/null 2>&1 || die "This script requires docker but its engine is unreachable. Aborting."

[[ ${1} && ${2} && ${3} ]] || usage

PROJECT_NS=${2//\//%2F}

REPOSITORY_IDS=$(curl -s -H "PRIVATE-TOKEN:${GITLAB_TOKEN}" \
                   "https://$1/api/v4/projects/${PROJECT_NS}/registry/repositories/" |
                     jq -r '.[].id' 2>/dev/null)
[[ ${REPOSITORY_IDS} ]] || die "$1/$2 has no docker images"

TMPFILE=$(mktemp -u /tmp/$ME.XXXXXX)

for REPOSITORY_ID in $REPOSITORY_IDS; do

  TAGS_URL="https://$1/api/v4/projects/${PROJECT_NS}/registry/repositories/${REPOSITORY_ID}/tags?per_page=100"
  
  TOTAL_PAGES=$(curl -sI -X HEAD -H "PRIVATE-TOKEN:${GITLAB_TOKEN}" ${TAGS_URL} |
                    sed -nE 's/X-Total-Pages:[[:space:]]*([^'$'\r'']*)'$'\r''?/\1/ip')
  [[ $TOTAL_PAGES =~ ^[0-9]+$ ]] || die "Error getting total page number using HTTP HEAD on $TAGS_URL (got $TOTAL_PAGES)"

  for PAGE in $(seq 1 $TOTAL_PAGES); do
    curl -s -H "PRIVATE-TOKEN:${GITLAB_TOKEN}" "${TAGS_URL}&page=${PAGE}" |
        jq -r '.[].location'
  done |
    sed -E "s#(.*)#docker pull \1 \&\& docker tag \1 \1#g
            s#(.*)($2)(.*:.*)#\1$3\3#i" |
      tee -a $TMPFILE

done

cat << EOM >> $TMPFILE
while true; do
    read -p "Do you want to push the images now? [Y/n] " yn
    case \${yn:-Y} in
        [Yy]* ) break;;
        * ) echo "Abort."; exit;;
    esac
done
EOM

tac $TMPFILE | sed '1,7d' | tac |
  sed -E "s#.* (.*)#docker push \1#" |
    tee -a $TMPFILE

[[ -f $TMPFILE ]] &&
  chmod +x $TMPFILE &&
    echo "You can now review the generated script in stdout or in $TMPFILE and if it looks fine for you just execute it." ||
      die "Something went wrong, sorry :("

@Smasherr, I had the same issue as @xenomachina and was able to fix it by swapping the regex within the sed statement to "s#(.*)($2)(.*:.*)#\1$3\3#". The current script will grab more than just $2 (the previous project path), clobbering any sub-paths in the Docker image (like @xenomachina's foo-image and bar-image under myproject. This change moves those sub-paths into match group 3 so that they are preserved.

Thanks for the awesome script, this saved us a lot of trouble while we restructured our repos and made it possible to put things just the way we needed them.

Hey @salim-runsafe, now I also able to see this issue that was initially discovered by @xenomachina. I appreciate very much your feedback and your fix of the regex.
Furthermore, I've discovered an issue in line 79 - there was a while read command, which just ate the first line and was totally superfluous. I've got rid of it.

Hey @salim-runsafe, now I also able to see this issue that was initially discovered by @xenomachina. I appreciate very much your feedback and your fix of the regex.
Furthermore, I've discovered an issue in line 79 - there was a while read command, which just ate the first line and was totally superfluous. I've got rid of it.

@Smasherr would this fix the bug (which I'm just now reporting) that the last image to be pushed would be left out of the generated script? To clarify, if you had a repo with only one image it would pull it down correctly, but there would be no line to push it. If you had a repo with 100 images it would pull 100 and only push the first 99.

Hey @salim-runsafe, now I also able to see this issue that was initially discovered by @xenomachina. I appreciate very much your feedback and your fix of the regex.
Furthermore, I've discovered an issue in line 79 - there was a while read command, which just ate the first line and was totally superfluous. I've got rid of it.

@Smasherr would this fix the bug (which I'm just now reporting) that the last image to be pushed would be left out of the generated script? To clarify, if you had a repo with only one image it would pull it down correctly, but there would be no line to push it. If you had a repo with 100 images it would pull 100 and only push the first 99.

I just tested it and it does seem to fix that. Thanks!

Fixing bugs before they are being reported is the best way to run it 😁

I moved to OSX and realized that this script doesn't work on it because many tools are not GNU but BSD compliant. Hence today's update with improved compatibility. Also tested it with busybox.

Hi @Smasherr
FYI, I tried to use your script on a repository with less than 100 tags and it failed to set the TOTAL_PAGES. I had to manual set the TOTAL_PAGES to 1 for it to work. Thank you for this very helpful script! It saved us a lot of time.

Thanks for your feedback @JanWendler. Perhaps, the API has changed, and I'm gonna check this.

@JanWendler I just tested the script with our internal GitLab installation and with gitlab.com - it works with both, so the HTTP header X-Total-Pages is available. Now there might be an incompatibility with the sed expression, as it is quite complicated.

Do you know if at least the validation in line 57 worked for you? What did you get as an output there?

To investigate your problem further, it would be helpful to see the output of the script in tracing mode. To do this, simply append -x to the shebang in line 1. And don`t forget to mask sensitive data if you want to paste the logs ;-)

@Smasherr This is the output:

$ ./copy_images.sh <our_server> <original_repo> jan.wendler/temp
++ basename ./copy_images.sh
+ ME=copy_images.sh
+ DEPENDS='docker curl jq tac'
+ [[ -n <Token> ]]
+ for CMD in $DEPENDS
+ command -v docker
+ for CMD in $DEPENDS
+ command -v curl
+ for CMD in $DEPENDS
+ command -v jq
+ for CMD in $DEPENDS
+ command -v tac
+ docker ps
+ [[ -n <our_server> ]]
+ [[ -n <original_repo> ]]
+ [[ -n jan.wendler/temp ]]
+ PROJECT_NS=<original_repo_%2F>
++ curl -s -H PRIVATE-TOKEN:<Token> https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/
++ jq -r '.[].id'
+ REPOSITORY_IDS=1702
+ [[ -n 1702 ]]
++ mktemp -u /tmp/copy_images.sh.XXXXXX
+ TMPFILE=/tmp/copy_images.sh.AIoZz4
+ for REPOSITORY_ID in $REPOSITORY_IDS
+ TAGS_URL='https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100'
++ curl -sI -X HEAD -H PRIVATE-TOKEN:<Token> 'https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100'
++ sed -nE 's/X-Total-Pages:[[:space:]]*([^]*)?/\1/ip'
sed: -e expression #1, char 41: unterminated `s' command
+ TOTAL_PAGES=
+ [[ '' =~ ^[0-9]+$ ]]
+ die 'Error getting total page number using HTTP HEAD on https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100 (got )'
+ [[ -n Error getting total page number using HTTP HEAD on https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100 (got ) ]]
+ [[ -t 2 ]]
+ printf '\e[31;1m%s\e[0m\n' 'Error getting total page number using HTTP HEAD on https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100 (got )'
Error getting total page number using HTTP HEAD on https://<our_server>/api/v4/projects/<original_repo_%2F>/registry/repositories/1702/tags?per_page=100 (got )
+ exit 1

I'm working on Windows 10 with an elevated gitbash console. I hope this helps : )