Given a DockerHub repo and tag, return a list of identical manifest tags

registry.sh

#!/usr/bin/env bash

# only supports hub.docker.com for now
registry="${1:-"https://registry.hub.docker.com"}"
# limited to 100 for hub.docker.com
page_size="${2:-100}"

# avoid reading all pages if at least one match is found
quick=1

# returns a json array of all the images associated with the provided tag
get_manifest_images() {

    local repo="${1}"
    local tag="${2}"

    local next
    local images

    next="${registry}/v2/repositories/${repo}/tags/?page=1&page_size=${page_size}"

    while :
    do
        images="$(curl -fsSL "${next}" | jq -r --arg TAG "${tag}" '.results[] | select(.name==$TAG) | .images | 
            sort_by(.digest)')" || { printf "" ; return ; }

        [ -n "${images}" ] && break
        
        results="$(curl -fsSL "${next}" | jq -r '.results | length')"
        [ "${results}" -lt 1 ] && break
        next=$(curl -fsSL "${next}" | jq -r '.next')
        [ "${next}" = "null" ] && break
        sleep 1
    done

    echo "${images}"
}

# returns a list of all identical manifests of the given tag
get_aliases() {
    local repo="${1}"
    local tag="${2:-"latest"}"
    local regexp="${3:-".*"}"

    local next
    local results
    local images
    local matches=()

    images="$(get_manifest_images "${repo}" "${tag}")"

    [ -n "${images}" ] || { printf "" ; return ; }

    next="${registry}/v2/repositories/${repo}/tags/?page=1&page_size=${page_size}"

    while :
    do
        mapfile -t tmparr < <(curl -fsSL "${next}" | \
            jq -r --arg REGEXP "${regexp}" --argjson IMAGES "${images}" '.results[] | 
            select(.images | sort_by(.digest)==$IMAGES) | select(.name | test($REGEXP)) | .name') || { printf "" ; return ; }

        if [ "${#tmparr[@]}" -lt 1 ]
        then
            [ ${#matches[@]} -gt 0 ] && [ -n "${quick}" ] && break
        else
            matches=("${matches[@]}" "${tmparr[@]}")
        fi
        
        results="$(curl -fsSL "${next}" | jq '.results | length')"
        [ "${results}" -lt 1 ] && break
        next=$(curl -fsSL "${next}" | jq -r '.next')
        [ "${next}" = "null" ] && break
        sleep 1
    done

    printf '%s\n' "${matches[@]}"
}

$ . ./registry.sh

$ get_aliases library/node latest
latest
current-bullseye
current
bullseye
17.0.1-bullseye
17.0.1
17.0-bullseye
17.0
17-bullseye
17

$ get_aliases library/node 16
lts-gallium
lts-buster
lts
gallium-buster
gallium
16.13.0-buster
16.13.0
16.13-buster
16.13
16-buster
16

$ get_aliases library/node 16 '^[0-9]+\.[0-9]+\.[0-9].+$'
16.13.0-buster

$ get_aliases balenalib/raspberrypi4-64-node 12 '^[0-9]+\.[0-9]+\.[0-9].+$'
12.22.7-20211014
12.22.7-run
12.22.7-run-20211014
12.22.7-latest
12.22.7-latest-20211014
12.22.7-latest-run
12.22.7-latest-run-20211014
12.22.7-bullseye
12.22.7-bullseye-20211014
12.22.7-bullseye-run
12.22.7-bullseye-run-20211014