Docker inspect 命令

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2016-07-04 by dongnan

问题描述

使用 docker exec xxx ifconfig 获取容器IP失败，提示环境变量中，找不到 ifconfig 命令。 这是因为好多镜像为了减少体积，没有安装 ifconfig 等基础命令：

# 执行命令
docker exec 4fb49ce6141d ifconfig

exec: "ifconfig": executable file not found in $PATH

我们可以使用 docker inspect 命令来查看容器IP。

举个栗子

对于容器

针对 exec 命令错误，可以使用 docker inspect 参数，获取容器的全部变量，这其中也有IP地址，例如：

docker inspect 4fb49ce6141d | grep '"IPAddress'

       "IPAddress": "172.17.0.2",
                "IPAddress": "172.17.0.2",

成功查到容器IP地址。

对于镜像

除了获取容器相关变量，inspect 还可以获得 images 相关变量，例如：

docker inspect ubuntu-supervisor

[
{
    "Id": "0bd51a6e54a8247e2843c8fc81d925fa81ff426160b22d6384b4f00435bf3774",
    "RepoTags": [
        "ubuntu-supervisor:latest"
    ],
    "RepoDigests": [],
    "Parent": "b2755d5841ab2b41821abe8a75858b787e4ff0f51b93cd249ebd2e27c10942d0",
    "Comment": "",
    "Created": "2016-03-24T05:49:16.722637969Z",
    "Container": "a38e5a1f80fd6f6a2234f857aa2da853af8748087182a06b16b3f039995a2768",
    "ContainerConfig": {
        "Hostname": "e611e15f9c9d",
        "Domainname": "",
        "User": "",
        "AttachStdin": false,
        "AttachStdout": false,
        "AttachStderr": false,
        "ExposedPorts": {
            "22/tcp": {},
            "80/tcp": {}
        },
        "Tty": false,
        "OpenStdin": false,
        "StdinOnce": false,
        "Env": [
            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        ],
        "Cmd": [
            "/bin/sh",
            "-c",
            "#(nop) CMD [\"/usr/bin/supervisord\"]"
        ],
        "Image": "b2755d5841ab2b41821abe8a75858b787e4ff0f51b93cd249ebd2e27c10942d0",
        "Volumes": null,
        "WorkingDir": "",
        "Entrypoint": null,
        "OnBuild": [],
        "Labels": {}
    },
    "DockerVersion": "1.9.1",
    "Author": "dongnan \u003chttp://ywwd.net\u003e",
    "Config": {
        "Hostname": "e611e15f9c9d",
        "Domainname": "",
        "User": "",
        "AttachStdin": false,
        "AttachStdout": false,
        "AttachStderr": false,
        "ExposedPorts": {
            "22/tcp": {},
            "80/tcp": {}
        },
        "Tty": false,
        "OpenStdin": false,
        "StdinOnce": false,
        "Env": [
            "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
        ],
        "Cmd": [
            "/usr/bin/supervisord"
        ],
        "Image": "b2755d5841ab2b41821abe8a75858b787e4ff0f51b93cd249ebd2e27c10942d0",
        "Volumes": null,
        "WorkingDir": "",
        "Entrypoint": null,
        "OnBuild": [],
        "Labels": {}
    },
    "Architecture": "amd64",
    "Os": "linux",
    "Size": 0,
    "VirtualSize": 247670721,
    "GraphDriver": {
        "Name": "aufs",
        "Data": null
    }
}
]

帮助

# 执行命令
docker inspect --help

Usage:    docker inspect [OPTIONS] CONTAINER|IMAGE [CONTAINER|IMAGE...]
Return low-level information on a container or image

  -f, --format=       Format the output using the given go template
  --help=false        Print usage
  -s, --size=false    Display total file sizes if the type is container
  --type=             Return JSON for specified type, (e.g image or container)