如何使用docker命令的“ --format”选项？

我似乎找不到任何有关如何在现实生活中使用docker命令的“ --format”选项的好的文档。我知道如何使用Go模板。但是特定于docker，我怎么知道可以使用哪些占位符？。我确实发现占位符区分大小写，这似乎是不幸的。默认输出也无济于事，因为（我假设）它没有显示我可能使用的所有内容，其中的列全为大写，有时它们之间有空格。例如，docker inspect的列名为“ CONTAINER ID”。下划线，引号方案等的组合都不会使该名称起作用。我发现它是“ {{.ID}}”。

我应该如何使用“ --format”？如何发现任何给定docker对象的占位符？

本文可能是一个好的开始。

#1 楼

我冒着被低估的风险，但是我发现Go模板超出了最基本的用例，是噩梦。不要误会我的意思：它们非常强大，您可以通过阅读文档来猜测，但我发现语法不友好，对于大多数复杂的情况，我更喜欢使用jq解析JSON输出。无论如何：

格式化expect命令

sho$ CID=$(sudo docker run --rm -d busybox sleep 3000)                                                                                         
sh$ sudo docker inspect $CID
[
    {
        "Id": "0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967",
        "Created": "2019-02-05T16:41:40.040349047Z",
        "Path": "sleep",
        "Args": [
            "3000"
        ],
        "State": {
            "Status": "running",
            "Running": true,
            "Paused": false,
            "Restarting": false,
            "OOMKilled": false,
            "Dead": false,
            "Pid": 26467,
            "ExitCode": 0,
            "Error": "",
            "StartedAt": "2019-02-05T16:41:40.659056612Z",
            "FinishedAt": "0001-01-01T00:00:00Z"
        },
        "Image": "sha256:3a093384ac306cbac30b67f1585e12b30ab1a899374dabc3170b9bca246f1444",
        "ResolvConfPath": "/var/lib/docker/containers/0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967/resolv.conf",
        "HostnamePath": "/var/lib/docker/containers/0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967/hostname",
        "HostsPath": "/var/lib/docker/containers/0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967/hosts",
        "LogPath": "/var/lib/docker/containers/0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967/0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967-json.log",
        "Name": "/vibrant_shaw",
        "RestartCount": 0,
        "Driver": "aufs",
        "Platform": "linux",
        "MountLabel": "",
        "ProcessLabel": "",
        "AppArmorProfile": "docker-default",
        "ExecIDs": null,
        "HostConfig": {
            "Binds": null,
            "ContainerIDFile": "",
           "LogConfig": {
                "Type": "json-file",
                "Config": {}
            },
            "NetworkMode": "default",
            "PortBindings": {},
            "RestartPolicy": {
                "Name": "no",
                "MaximumRetryCount": 0
            },
            "AutoRemove": true,
            "VolumeDriver": "",
            "VolumesFrom": null,
            "CapAdd": null,
            "CapDrop": null,
            "Dns": [],
            "DnsOptions": [],
            "DnsSearch": [],
            "ExtraHosts": null,
            "GroupAdd": null,
            "IpcMode": "shareable",
            "Cgroup": "",
            "Links": null,
            "OomScoreAdj": 0,
            "PidMode": "",
            "Privileged": false,
            "PublishAllPorts": false,
            "ReadonlyRootfs": false,
            "SecurityOpt": null,
            "UTSMode": "",
            "UsernsMode": "",
            "ShmSize": 67108864,
            "Runtime": "runc",
            "ConsoleSize": [
                0,
                0
            ],
            "Isolation": "",
            "CpuShares": 0,
            "Memory": 0,
            "NanoCpus": 0,
            "CgroupParent": "",
            "BlkioWeight": 0,
            "BlkioWeightDevice": [],
            "BlkioDeviceReadBps": null,
            "BlkioDeviceWriteBps": null,
            "BlkioDeviceReadIOps": null,
            "BlkioDeviceWriteIOps": null,
            "CpuPeriod": 0,
            "CpuQuota": 0,
            "CpuRealtimePeriod": 0,
            "CpuRealtimeRuntime": 0,
            "CpusetCpus": "",
            "CpusetMems": "",
            "Devices": [],
            "DeviceCgroupRules": null,
            "DiskQuota": 0,
            "KernelMemory": 0,
            "MemoryReservation": 0,
            "MemorySwap": 0,
            "MemorySwappiness": null,
            "OomKillDisable": false,
            "PidsLimit": 0,
            "Ulimits": null,
            "CpuCount": 0,
            "CpuPercent": 0,
            "IOMaximumIOps": 0,
            "IOMaximumBandwidth": 0,
            "MaskedPaths": [
                "/proc/acpi",
                "/proc/kcore",
                "/proc/keys",
                "/proc/latency_stats",
                "/proc/timer_list",
                "/proc/timer_stats",
                "/proc/sched_debug",
                "/proc/scsi",
                "/sys/firmware"
            ],
            "ReadonlyPaths": [
                "/proc/asound",
                "/proc/bus",
                "/proc/fs",
                "/proc/irq",
                "/proc/sys",
                "/proc/sysrq-trigger"
            ]
        },
        "GraphDriver": {
            "Data": null,
            "Name": "aufs"
        },
        "Mounts": [],
        "Config": {
            "Hostname": "0470a3549d2f",
            "Domainname": "",
            "User": "",
            "AttachStdin": false,
            "AttachStdout": false,
            "AttachStderr": false,
            "Tty": false,
            "OpenStdin": false,
            "StdinOnce": false,
            "Env": [
                "PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"
            ],
            "Cmd": [
                "sleep",
                "3000"
            ],
            "Image": "busybox",
            "Volumes": null,
            "WorkingDir": "",
            "Entrypoint": null,
            "OnBuild": null,
            "Labels": {}
        },
        "NetworkSettings": {
            "Bridge": "",
            "SandboxID": "654da638965d9bb26e394ba61036ea713bdccb6304eb09bee86f3c0611a26ca5",
            "HairpinMode": false,
            "LinkLocalIPv6Address": "",
            "LinkLocalIPv6PrefixLen": 0,
            "Ports": {},
            "SandboxKey": "/var/run/docker/netns/654da638965d",
            "SecondaryIPAddresses": null,
            "SecondaryIPv6Addresses": null,
            "EndpointID": "c69ef9cb870a3c477105c7bc19e370683886e4e3c62fac8444d3e1e097551250",
            "Gateway": "172.17.0.1",
            "GlobalIPv6Address": "",
            "GlobalIPv6PrefixLen": 0,
            "IPAddress": "172.17.0.3",
            "IPPrefixLen": 16,
            "IPv6Gateway": "",
            "MacAddress": "02:42:ac:11:00:03",
            "Networks": {
                "bridge": {
                    "IPAMConfig": null,
                    "Links": null,
                    "Aliases": null,
                    "NetworkID": "5ec8728b05efd5ce6bfde5cbe6e42f247348345e0fdfb305fda76566327fc151",
                    "EndpointID": "c69ef9cb870a3c477105c7bc19e370683886e4e3c62fac8444d3e1e097551250",
                    "Gateway": "172.17.0.1",
                    "IPAddress": "172.17.0.3",
                    "IPPrefixLen": 16,
                    "IPv6Gateway": "",
                    "GlobalIPv6Address": "",
                    "GlobalIPv6PrefixLen": 0,
                    "MacAddress": "02:42:ac:11:00:03",
                    "DriverOpts": null
                }
            }
        }
    }
]

返回标量属性

您可以按名称查询任何标量属性，以点开头：

sh$ sudo docker inspect $CID --format '{{.Id}}
0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967
sh$ sudo docker inspect $CID --format '{{.Name}} {{.Driver}}'
/vibrant_shaw aufs

# jq notation
sh$ sudo docker inspect $CID | jq '.[].Id'
"0470a3549d2f41efd0477cf8fc4eb3a27aca592f089c018ad24704031bbef967"

sh$ sudo docker inspect $CID | jq '.[]|(.Name,.Driver)'
"/vibrant_shaw"
"aufs"

还可以查询嵌套字段：

sh$ sudo docker inspect $CID --format '{{.State.Running}}'
true

# jq notation
sudo docker inspect $CID | jq '.[].State.Running'
true

返回整个对象和数组

，但是它不适用于嵌套结构：

sh$ sudo docker inspect $CID --format '{{.State}}'
{running true false false false false 26467 0  2019-02-05T16:41:40.659056612Z 0001-01-01T00:00:00Z <nil>}

您最终拥有数据，但是没有字段名称，这几乎没有用-除非您假设一些预定义的字段顺序（可能不安全）。

访问整个对象时，您有可能需要显式格式化程序：

sh$ sudo docker inspect $CID --format '{{json .State}}'
{"Status":"running","Running":true,"Paused":false,"Restarting":false,"OOMKilled":false,"Dead":false,"Pid":26467,"ExitCode":0,"Error":"","StartedAt":"2019-02-05T16:41:40.659056612Z","FinishedAt":"0001-01-01T00:00:00Z"}

# jq notation
sh$ sudo docker inspect $CID | jq '.[].State'
{
  "Status": "running",
  "Running": true,
  "Paused": false,
  "Restarting": false,
  "OOMKilled": false,
  "Dead": false,
  "Pid": 26467,
  "ExitCode": 0,
  "Error": "",
  "StartedAt": "2019-02-05T16:41:40.659056612Z",
  "FinishedAt": "0001-01-01T00:00:00Z"
}

数组的相同之处：

sh$ sudo docker inspect $CID --format '{{.HostConfig.ReadonlyPaths}}'
[/proc/asound /proc/bus /proc/fs /proc/irq /proc/sys /proc/sysrq-trigger]

sh$ sudo docker inspect $CID --format '{{json .HostConfig.ReadonlyPaths}}'
["/proc/asound","/proc/bus","/proc/fs","/proc/irq","/proc/sys","/proc/sysrq-trigger"]

sh$ sudo docker inspect $CID --format '{{join .HostConfig.ReadonlyPaths ":"}}'
/proc/asound:/proc/bus:/proc/fs:/proc/irq:/proc/sys:/proc/sysrq-trigger

# jq notation
sh$ sudo docker inspect $CID | jq '.[].HostConfig.ReadonlyPaths'
[
  "/proc/asound",
  "/proc/bus",
  "/proc/fs",
  "/proc/irq",
  "/proc/sys",
  "/proc/sysrq-trigger"
]
sh$ sudo docker inspect $CID | jq '.[].HostConfig.ReadonlyPaths | join(":")'
"/proc/asound:/proc/bus:/proc/fs:/proc/irq:/proc/sys:/proc/sysrq-trigger"

对象数组

更复杂（根据我有限的Go模板技能）正在访问嵌套在对象数组中的字段：

# This works as expected
sh$ sudo docker network inspect bridge --format '{{json .IPAM.Config}}'
[{"Subnet":"172.17.0.0/16","Gateway":"172.17.0.1"}]

# But not that
sudo docker network inspect bridge --format '{{.IPAM.Config.Gateway}}'

Template parsing error: template: :1:7: executing "" at <.IPAM.Config.Gateway>: can't evaluate field Gateway in type interface {}

当我想提取此类嵌套值时，我求助于一个明确的范围循环：

sh$ sudo docker network inspect bridge --format '{{range .IPAM.Config}}{{.Gateway}}{{end}}'
172.17.0.1

# jq notation
sh$ sudo docker network inspect bridge | jq '.[].IPAM.Config[].Gateway'
"172.17.0.1"

sh$ sudo docker network inspect bridge | jq -r '.[].IPAM.Config[].Gateway'
172.17.0.1

格式化ls命令

使用json格式化程序，我们可以获得（一些？全部？）您以后可以与--format一起使用的可能的选择器：

sh$ sudo docker network ls --format '{{json .}}'
{"CreatedAt":"2019-01-07 14:28:55.63238018 +0100 CET","Driver":"bridge","ID":"5ec8728b05ef","IPv6":"false","Internal":"false","Labels":"","Name":"bridge","Scope":"local"}
{"CreatedAt":"2019-02-05 15:36:57.701603791 +0100 CET","Driver":"bridge","ID":"45d6f09ca923","IPv6":"false","Internal":"false","Labels":"com.docker.compose.network=default,com.docker.compose.project=compose-demo,com.docker.compose.version=1.23.2","Name":"compose-demo_default","Scope":"local"}
{"CreatedAt":"2019-02-05 17:30:47.98883918 +0100 CET","Driver":"bridge","ID":"aaff418d1c56","IPv6":"false","Internal":"false","Labels":"com.docker.compose.network=net,com.docker.compose.project=compose-demo,com.docker.compose.version=1.23.2","Name":"compose-demo_net","Scope":"local"}
{"CreatedAt":"2018-05-26 10:31:48.149819089 +0200 CEST","Driver":"host","ID":"988954899b53","IPv6":"false","Internal":"false","Labels":"","Name":"host","Scope":"local"}
{"CreatedAt":"2018-05-26 10:31:48.118573602 +0200 CEST","Driver":"null","ID":"ce1680ed377f","IPv6":"false","Internal":"false","Labels":"","Name":"none","Scope":"local"}
{"CreatedAt":"2019-02-05 19:44:21.286955573 +0100 CET","Driver":"bridge","ID":"41c62c023d16","IPv6":"false","Internal":"false","Labels":"com.docker.compose.version=1.23.2,com.docker.compose.network=default,com.docker.compose.project=test","Name":"test_default","Scope":"local"}

这里，您可以看到docker network ls公开了“ ID”，“ Driver”和“范围”字段。您可以按照以下格式使用它们：

sh$ $ sudo docker network ls --format '{{.ID}}: {{.Driver}} ({{.Scope}})'
5ec8728b05ef: bridge (local)
45d6f09ca923: bridge (local)
aaff418d1c56: bridge (local)
988954899b53: host (local)
ce1680ed377f: null (local)
41c62c023d16: bridge (local)

两全其美

docker ... ls命令仅导出docker对象属性。根据您的需求，您可能更喜欢docker ... inspect $(docker ... ls -q)的内容。

例如，docker image ls不导出图像体系结构。但您可以使用docker image inspect获得它。如果您需要这些信息，可以使用类似以下的内容：

sh$ sudo docker image inspect \
         --format '{{.Id}}: {{.RepoTags}} ({{.Architecture}})' \
         $(sudo docker image ls -q)
sha256:fc37804350a8adea0b41dba0c413a6c967140ca2ed6dfeefdbe88d7868902406: [compose-demo_monitor:latest] (amd64)
sha256:a6f30c0890bca94e3cf5930ad5c3358b06cb38450e92d4ddabeb208ee34383f8: [compose-demo_app:latest] (amd64)
sha256:a79892b33e0bb51598e9311cc1d23ca8d0e3013a5a15fd67d202d22ffd08a6af: [] (amd64)
sha256:394c82635f220db389b8532e316001674965b51679dbc8dff747d5f224e6d568: [] (amd64)
sha256:95f0c755feb65af441c0cb8727bb13b35517977a3bed06e4a3456c95d6a69dd4: [redis:5.0-alpine] (amd64)
sha256:1f6c34f7921c7b50ef4452737399b5cff0eb834fc183d188d82886fd23b7fc34: [node:8] (amd64)
sha256:3a093384ac306cbac30b67f1585e12b30ab1a899374dabc3170b9bca246f1444: [busybox:latest] (amd64)

看来您的示例全部取决于被“检查”的命令。这行得通：码头工人检查$ CID --format'{{.Id}}'。但这是行不通的：docker container ls --format'{{.Id}}'。

–托德·沃尔顿（Todd Walton）
19年2月5日在19:26

@ToddWalton您始终可以使用--format'{{json。}}来检查由ls命令导出的字段。我已经编辑了答案，在末尾添加了一个部分来显示如何执行此操作。

–西尔万·勒鲁（Sylvain Leroux）
19年2月5日在19:44

@ToddWalton顺便说一句，我怀疑，像它们的外壳程序一样，docker ... ls命令的输出是为了“供人食用”。根据您的用例，您可能会考虑类似docker image inspect --format ... $（docker image ls -q）

–西尔万·勒鲁（Sylvain Leroux）
19年2月5日在19:59

正是我想要的，谢谢！：D

–阿尼鲁德M
19年8月9日在6:44

编程黑洞网

如何使用docker命令的“ --format”选项？

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#1 楼

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