Linux通过curl访问docker.sock/API执行docker操作

官方API doc: https://docs.docker.com/engine/api/v1.41/

官方API doc(with example): https://docs.docker.com/engine/api/sdk/examples/

不同版本的docker的api doc: https://docs.docker.com/engine/api/#api-version-matrix

tips: Linux下对socket进行抓包

通过curl socket完成镜像拉取操作

基本报文

POST /v1.41/images/create?fromImage=10.82.123.123%2Fpublic%2Fmaven&tag=3.3.9-public HTTP/1.1
Host: docker
User-Agent: Docker-Client/20.10.17 (linux)
Content-Length: 0
Content-Type: text/plain

命令实现

curl --unix-socket /var/run/docker.sock "http://localhost/v1.41/images/create?fromImage=10.82.123.123%2Fpublic%2Fmaven&tag=3.3.9-public" -X POST

如果拉取镜像需要认证可以加上http header

X-Registry-Auth: eyJ1c2VybmFtZSI6ImFkbWluIiwicGFzc3dvcmQiOiJwYXNzd29yZCIsInNlcnZlcmFkZHJlc3MiOiIxMC44Mi4xMjMuMTIzIn0=

通过curl socket获取镜像dangling镜像信息

curl -s --unix-socket /var/run/docker.sock "http://localhost/v1.41/images/json?filters=\{\"dangling\":\[\"true\"\]\}"

通过curl socket获取指定REPOSITORY+TAG镜像信息

注意是全名字匹配

curl -s --unix-socket /var/run/docker.sock "http:/v1.24/images/json?filters=\{\"reference\":\{\"mysql\":true\}\}"

[{"Containers":-1,"Created":1602576181,"Id":"sha256:8e85dd5c32558ea5c22cc4786cff512c1940270a50e7dbc21ad2df42f0637de4","Labels":null,"ParentId":"","RepoDigests":["mysql@sha256:86b7c83e24c824163927db1016d5ab153a9a04358951be8b236171286e3289a4"],"RepoTags":["mysql:8.0.21"],"SharedSize":-1,"Size":544193587,"VirtualSize":544193587},{"Containers":-1,"Created":1532654095,"Id":"sha256:6bb891430fb6e2d3b4db41fd1f7ece08c5fc769d8f4823ec33c7c7ba99679213","Labels":null,"ParentId":"","RepoDigests":["mysql@sha256:aaba540cdd9313645d892f4f20573e8b42b30e5be71c054b7befed2f7da5f85b"],"RepoTags":["mysql:5.7.22"],"SharedSize":-1,"Size":371941626,"VirtualSize":371941626}]

如果需要半匹配，用 * 号即可(测试下来发现好像只能省略后缀，不能省略前缀，可以匹配tag，区分大小写)

curl -s --unix-socket /var/run/docker.sock "http:/v1.24/images/json?filters=\{\"reference\":\{\"*m*\":true\}\}"|jq .

[
  {
    "Containers": -1,
    "Created": 1665115518,
    "Id": "sha256:9622db9aed586c97c6a18d912b965f3d4c02fdf749650c7ee57a9a6b8cde3dd7",
    "Labels": null,
    "ParentId": "",
    "RepoDigests": null,
    "RepoTags": [
      "sonarqube:8.9.9-community"
    ],
    "SharedSize": -1,
    "Size": 499466355,
    "VirtualSize": 499466355
  },
  {
    "Containers": -1,
    "Created": 1612947183,
    "Id": "sha256:8415759abc07b3d3dcd43cecd924caa3ed68bc5d4a4166e50565a4a1b344a7e5",
    "Labels": null,
    "ParentId": "",
    "RepoDigests": null,
    "RepoTags": [
      "node:14.15.5-stretch-slim"
    ],
    "SharedSize": -1,
    "Size": 166658514,
    "VirtualSize": 166658514
  },
  {
    "Containers": -1,
    "Created": 1602576181,
    "Id": "sha256:8e85dd5c32558ea5c22cc4786cff512c1940270a50e7dbc21ad2df42f0637de4",
    "Labels": null,
    "ParentId": "",
    "RepoDigests": [
      "mysql@sha256:86b7c83e24c824163927db1016d5ab153a9a04358951be8b236171286e3289a4"
    ],
    "RepoTags": [
      "mysql:8.0.21"
    ],
    "SharedSize": -1,
    "Size": 544193587,
    "VirtualSize": 544193587
  },
  {
    "Containers": -1,
    "Created": 1532654095,
    "Id": "sha256:6bb891430fb6e2d3b4db41fd1f7ece08c5fc769d8f4823ec33c7c7ba99679213",
    "Labels": null,
    "ParentId": "",
    "RepoDigests": [
      "mysql@sha256:aaba540cdd9313645d892f4f20573e8b42b30e5be71c054b7befed2f7da5f85b"
    ],
    "RepoTags": [
      "mysql:5.7.22"
    ],
    "SharedSize": -1,
    "Size": 371941626,
    "VirtualSize": 371941626
  }
]

一个简单的通过curl + socket进行清理镜像的例子

#!/bin/env bash
docker_api_version=v1.41
curl_options=(
  "-s"
  "--unix-socket" "/var/run/docker.sock"
)
dangling_images=(`curl "${curl_options[@]}" "http://localhost/${docker_api_version}/images/json?filters=%7B%22dangling%22%3A%5B%22true%22%5D%7D&all=1" | jq -r .[].Id`)
# TODO: clean up stopped non-k8s containers
echo "cleaning dangline images:"
for image in ${dangling_images[*]}
do
  echo $image
  (set -x; curl -X DELETE "${curl_options[@]}" "http://localhost/${docker_api_version}/images/$image" )
done

echo -n "cleaning images without specific string: "
echo ${image_exclude:="(/kube-system/)|(/library/)"}
clean_images=(`curl "${curl_options[@]}" "http://localhost/${docker_api_version}/images/json"|jq -r ".[].RepoTags[]"|grep -v none|grep -Ev "${image_exclude}"`)
for image in ${clean_images[*]}
do
  echo $image
  (set -x; curl -X DELETE "${curl_options[@]}" "http://localhost/${docker_api_version}/images/$image" )
done