从第三方存储库中检索Docker图像标签

Question

对于直接来自Docker Hub的Docker图像，我可以通过击中其存储库API来检索图像的当前标签列表。例如，https://registry.hub.docker.com/v1/repositories/python/tags将为我提供可以与docker pull python:<tag>一起使用的标签列表。

用于弹性搜索，我正在使用他们的官方存储库，并且可以使用 docker pull docker.elastic.co/elasticsearch/elasticsearch:6.4.0

绘制图像

但是，我不知道如何从该存储库中获取标签列表。我尝试了

https://docker.elastic.co/elasticsearch/elasticsearch/tags
https://docker.elastic.co/v1/repositories/elasticsearch
https://docker.elastic.co/v2/repositories/elasticsearch/elasticsearch/_manifests/tags

..和其他几个变体。什么URL/API端点是Docker命令行工具将其转换为后端请求上的存储库/图像名称？

Answer 1

事实证明，docker.elastic.co正在运行V2 Docker注册表，因此需要V2 API命令和令牌身份验证。试图最初获得标签的结果是401，其中包含有关如何获取令牌的信息：

http https://docker.elastic.co/v2/elasticsearch/elasticsearch/tags/list                                                                                                                       (566ms)  
HTTP/1.1 401 Unauthorized
Connection: keep-alive
Content-Length: 170
Content-Type: application/json; charset=utf-8
Date: Thu, 09 May 2019 15:24:42 GMT
Docker-Distribution-Api-Version: registry/2.0
Www-Authenticate: Bearer realm="https://docker-auth.elastic.co/auth",service="token-service",scope="repository:elasticsearch/elasticsearch:pull"
X-Content-Type-Options: nosniff
{
    "errors": [
        {
            "code": "UNAUTHORIZED",
            "detail": [
                {
                    "Action": "pull",
                    "Class": "",
                    "Name": "elasticsearch/elasticsearch",
                    "Type": "repository"
                }
            ],
            "message": "authentication required"
        }
    ]
}

使用WWW-Authenticate中的信息向给定的service和scope请求令牌：

http "https://docker-auth.elastic.co/auth?service=token-service&scope=repository:elasticsearch/elasticsearch:pull"                                                                            (567ms)  
HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 790
Content-Type: application/json
Date: Thu, 09 May 2019 15:25:37 GMT
{
    "token": "some-long-token"
}

最后，使用令牌：

提出请求

http -v https://docker.elastic.co/v2/elasticsearch/elasticsearch/tags/list 'Authorization: Bearer some-long-token'
HTTP/1.1 200 OK
Connection: keep-alive
Content-Length: 1765
Content-Type: application/json; charset=utf-8
Date: Thu, 09 May 2019 15:26:18 GMT
Docker-Distribution-Api-Version: registry/2.0
X-Content-Type-Options: nosniff
{
    "name": "elasticsearch/elasticsearch",
    "tags": [
        "5.0.0-731e78df",
        "5.0.0-86a0b164",
        "5.0.0-alpha5",
        "5.0.0-beta1",
        "5.0.0-ccd69424",
        "5.0.0-rc1",
        "5.0.0",
        ...
        ...
        ...

Answer 2

您可以尝试以相同的方式为Python获取标签/可用版本列表。

示例：https：//registry.hub.docker.com/v1/repositories/elasticsearch/tags

样本出口：[{"layer": "", "name": "1"}, {"layer": "", "name": "1-alpine"}]

因此，您要做的事情，您将在Shell脚本中提供标签列表，并要求他们选择。然后，基于此，您将在自定义Docker文件中进行Docker拉动并运行这些命令吗？