给定标签“latest”,我们想在Docker Hub上找到具有相同图像ID的另一个标签.
以下是如何使用Docker Hub API v2查找repo的所有标记：
TOKEN=$(curl -s -H "Content-Type: application/json" -X POST -d '{"username": "'${UNAME}'","password": "'${UPASS}'"}' https://hub.docker.com/v2/users/login/ | jq -r .token)
curl -s -H "Authorization: JWT ${TOKEN}" https://hub.docker.com/v2/repositories/fluent/fluentd/tags/?page_size=100 | jq
(见gist.github.com/kizbitz)
不幸的是,它不包含图像ID,但始终为此键的“null”值：
$curl -s -H "Authorization: JWT ${TOKEN}" https://hub.docker.com/v2/repositories/fluent/fluentd/tags/?page_size=100 | jq
{
"count": 36,"next": null,"previous": null,"results": [
...
{
"name": "v0.14.11","full_size": 11964464,"id": 7084687,"repository": 219785,"creator": 2923,"last_updater": 2923,"last_updated": "2016-12-27T07:16:41.294807Z","image_id": null,"v2": true,"platforms": [
5
]
},...
不幸的是,图像ID与上面JSON中的`id`不同.
$docker images | grep fluent
docker.io/fluent/fluentd v0.14.11 1441d57beff9 3 weeks ago 38.25 MB
从理论上讲,应该可以通过此Docker Registry调用访问Docker清单以及图像ID,但它也没有帮助：
$curl -s -H "Authorization: JWT ${TOKEN}" "https://registry.hub.docker.com/v2/fluent/fluentd/manifests/latest"
{"errors":[{"code":"UNAUTHORIZED","message":"authentication required","detail":[{"Type":"repository","Name":"fluent/fluentd","Action":"pull"}]}]}
(见stackoverflow.com)
这是Docker GitHub仓库中的类似问题,但我仍然无法找到解决方案：https://github.com/docker/distribution/issues/1490.
P.S.：这是我试图推送测试图像的Docker版本：
$docker version
Client:
Version: 1.12.6
API version: 1.24
Package version: docker-common-1.12.6-5.git037a2f5.fc25.x86_64
Go version: go1.7.4
Git commit: 037a2f5/1.12.6
Built: Wed Jan 18 12:11:29 2017
OS/Arch: linux/amd64
Docker Registry API v2使用图像摘要而不是图像ID来区分图像标识.
通过进行以下API调用,可以从HTTP响应头的Docker-Content-Digest获取图像摘要：
$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/latest
HTTP/1.1 200 OK
Content-Length: 1982
Content-Type: application/vnd.docker.distribution.manifest.v2+json
Docker-Content-Digest: sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db
Docker-Distribution-Api-Version: registry/2.0
Etag: "sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db"
Date: Tue,24 Jan 2017 13:34:53 GMT
Strict-Transport-Security: max-age=31536000
...
可以使用以下API调用获取所有标记：
$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"]}
基于以上所述,为了找到与特定标签相同的摘要,它将是如下的脚本.
#!/bin/bash
REPOSITORY=$1
TARGET_TAG=$2
# get authorization token
TOKEN=$(curl -s "https://auth.docker.io/token?service=registry.docker.io&scope=repository:$REPOSITORY:pull" | jq -r .token)
# find all tags
ALL_TAGS=$(curl -s -H "Authorization: Bearer $TOKEN" https://index.docker.io/v2/$REPOSITORY/tags/list | jq -r .tags[])
# get image digest for target
TARGET_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 tags
for 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"
fi
done
结果如下：
$./find_same_digest.sh fluent/fluentd latest
latest sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db
stable sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db
v0.12.31 sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db
v0.12 sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db
如果你想检查本地图像的摘要,可以使用docker images –digest：
$docker images --digests | grep fluentd
fluent/fluentd latest sha256:eaea1edffc34cff3b5e31ee738ea56e46326f90731b4139a19948814a4f0a4db 1788ee7dcfcc 14 hours ago 35.41 MB
