如何通过Docker Hub API确定标签的Docker映像ID？

Docker Registry API v2使用图像摘要而非图像ID来区分图像身份。

可以

Docker-Content-Digest

$ REPOSITORY=fluent/fluentd$ TOKEN=$(curl -s "https://auth.docker.io/token?service=registry.docker.io&scope=repository:$REPOSITORY:pull" | jq -r .token)$ curl -s -D - -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.docker.distribution.manifest.v2+json" https://index.docker.io/v2/$REPOSITORY/manifests/latestHTTP/1.1 200 OKContent-Length: 1982Content-Type: application/vnd.docker.distribution.manifest.v2+jsonDocker-Content-Digest: sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4dbDocker-Distribution-Api-Version: registry/2.0Etag: "sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db"Date: Tue, 24 Jan 2017 13:34:53 GMTStrict-Transport-Security: max-age=31536000...

可以通过以下API调用获取所有标签：

$ curl -s -H "Authorization: Bearer $TOKEN" https://index.docker.io/v2/$REPOSITORY/tags/list{"name":"fluent/fluentd","tags":["edge-onbuild","edge","jemalloc","latest-onbuild","latest","onbuild","stable-onbuild","stable","ubuntu-base","v0.12-latest-onbuild","v0.12-latest","v0.12-onbuild","v0.12.16","v0.12.18","v0.12.19","v0.12.20","v0.12.21","v0.12.23","v0.12.24","v0.12.26-2","v0.12.26-onbuild","v0.12.26","v0.12.27-onbuild","v0.12.27","v0.12.28-onbuild","v0.12.28","v0.12.29-onbuild","v0.12.29","v0.12.30-onbuild","v0.12.30","v0.12.31-onbuild","v0.12.31","v0.12","v0.14-latest-onbuild","v0.14-latest","v0.14-onbuild","v0.14.1","v0.14.10-onbuild","v0.14.10","v0.14.11-onbuild","v0.14.11","v0.14.2","v0.14.6","v0.14.8","v0.14"]}

基于上述内容，要查找与特定标签相同的摘要，它将是类似于以下内容的脚本。

#!/bin/bashREPOSITORY=$1TARGET_TAG=$2# get authorization tokenTOKEN=$(curl -s "https://auth.docker.io/token?service=registry.docker.io&scope=repository:$REPOSITORY:pull" | jq -r .token)# find all tagsALL_TAGS=$(curl -s -H "Authorization: Bearer $TOKEN" https://index.docker.io/v2/$REPOSITORY/tags/list | jq -r .tags[])# get image digest for targetTARGET_DIGEST=$(curl -s -D - -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.docker.distribution.manifest.v2+json" https://index.docker.io/v2/$REPOSITORY/manifests/$TARGET_TAG | grep Docker-Content-Digest | cut -d ' ' -f 2)# for each tagsfor tag in ${ALL_TAGS[@]}; do  # get image digest  digest=$(curl -s -D - -H "Authorization: Bearer $TOKEN" -H "Accept: application/vnd.docker.distribution.manifest.v2+json" https://index.docker.io/v2/$REPOSITORY/manifests/$tag | grep Docker-Content-Digest | cut -d ' ' -f 2)  # check digest  if [[ $TARGET_DIGEST = $digest ]]; then    echo "$tag $digest"  fidone

结果如下：

$ ./find_same_digest.sh fluent/fluentd latestlatest sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4dbstable sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4dbv0.12.31 sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4dbv0.12 sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db

如果要检查本地图像的摘要，可以使用以下命令获取

docker images --digests

$ docker images --digests | grep fluentdfluent/fluentd       latest   sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db   1788ee7dcfcc        14 hours ago        35.41 MB