修改已运行docker容器端口映射
前言
在项目中我们一般通过命令启动一个容器的时候，通常会通过命令指定容器与物理机网络端口的映射。例如下面这个命令就会运行一个nginx容器，并且指定它的容器内的端口80与物理机中的端口8080进行映射。
sudo docker run --name nginx-demo \
-p 8080:80 \
-d nginx
因为端口映射一般是在容器建立的时候就设置好的了，有时我们需要对端口映射进行修改的时候就显得束手无策了，貌似目前docker还没有提供可以修改容器的端口映射命令。在网上检索的一些修改的方式，发现是通过修改docker配置文件进行修改，具体的操作步骤如下。
一、找到需要修改的配置文件
第一步要找到我们需要修改容器端口映射配置文件，具体的路径一般是/var/lib/docker/containers/{{CONTAINER ID}},容器的CONTAINER ID可以通过命令docker ps -a找到，执行命令如下
[root@localhost]# docker ps -a
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
16aeecf6ed6f nginx "nginx -g 'daemon ..." 9 minutes ago Up 9 minutes 0.0.0.0:8080->80/tcp nginx-demo
其中16aeecf6ed6f就是我们要找的CONTAINER ID的部分前缀，该容器的配置目录名称就是已该名称前缀匹配的字符，我服务器上的完整CONTAINER ID是16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470
通过以下命令进入到容器配置目录，可以看到如下文件
[root@localhost /]# cd /var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470
[root@localhost 16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470]# ls
16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470-json.log checkpoints config.v2.json hostconfig.json hostname hosts resolv.conf resolv.conf.hash shm
其中文件hostconfig.json和 config.v2.json就是我们要修改的配置文件
二、停止docker服务器，修改端口映射配置文件
在修改配置文件之前，我们要将正在运行的docker服务停止，通过systemctl stop docker或者 service docker stop
通过vi命令打开hostconfig.json文件，看到内容如下(PS:原配置文件JSON格式有点混乱我用工具格式化了一下)
{
"Binds": null,
"ContainerIDFile": "",
"LogConfig": {
"Type": "json-file",
"Config": {}
},
"NetworkMode": "default",
"PortBindings": {
"80/tcp": [{
"HostIp": "",
"HostPort": "8080"
}]
},
"RestartPolicy": {
"Name": "no",
"MaximumRetryCount": 0
},
"AutoRemove": false,
"VolumeDriver": "",
"VolumesFrom": null,
"CapAdd": null,
"CapDrop": null,
"Dns": [],
"DnsOptions": [],
"DnsSearch": [],
"ExtraHosts": null,
"GroupAdd": null,
"IpcMode": "",
"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": null,
"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": -1,
"OomKillDisable": false,
"PidsLimit": 0,
"Ulimits": null,
"CpuCount": 0,
"CpuPercent": 0,
"IOMaximumIOps": 0,
"IOMaximumBandwidth": 0
}
从配置文件中可以看到字段名为PortBindings项下面有我们刚开始的创建容器时设定的端口映射项
"PortBindings": {
"80/tcp": [{
"HostIp": "",
"HostPort": "8080"
}]
}
我们将该项修改为我们需要映射的新端口，比如8081
"PortBindings": {
"80/tcp": [{
"HostIp": "",
"HostPort": "8081"
}]
}
然后继续修改第二个配置文件，通过vi命令打开hostconfig.json文件，看到内容如下(PS:原配置文件JSON格式有点混乱我用工具格式化了一下)
{
"StreamConfig": {},
"State": {
"Running": false,
"Paused": false,
"Restarting": false,
"OOMKilled": false,
"RemovalInProgress": false,
"Dead": false,
"Pid": 0,
"ExitCode": 0,
"Error": "",
"StartedAt": "2019-02-28T02:01:20.219978817Z",
"FinishedAt": "2019-02-28T02:23:34.188640596Z",
"Health": null
},
"ID": "16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470",
"Created": "2019-02-28T02:01:19.716013746Z",
"Managed": false,
"Path": "nginx",
"Args": ["-g", "daemon off;"],
"Config": {
"Hostname": "16aeecf6ed6f",
"Domainname": "",
"User": "",
"AttachStdin": false,
"AttachStdout": false,
"AttachStderr": false,
"ExposedPorts": {
"80/tcp": {}
},
"Tty": false,
"OpenStdin": false,
"StdinOnce": false,
"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin", "NGINX_VERSION=1.13.5-1~stretch", "NJS_VERSION=1.13.5.0.1.13-1~stretch"],
"Cmd": ["nginx", "-g", "daemon off;"],
"ArgsEscaped": true,
"Image": "nginx",
"Volumes": null,
"WorkingDir": "",
"Entrypoint": null,
"OnBuild": null,
"Labels": {
"maintainer": "NGINX Docker Maintainers \[email protected]\u003e"
},
"StopSignal": "SIGTERM"
},
"Image": "sha256:1e5ab59102ce46c277eda5ed77affaa4e3b06a59fe209fe0b05200606db3aa7a",
"NetworkSettings": {
"Bridge": "",
"SandboxID": "d681fbde606c98843af298b2645627f7f52f8445327b1e40306357fb2d999fd0",
"HairpinMode": false,
"LinkLocalIPv6Address": "",
"LinkLocalIPv6PrefixLen": 0,
"Networks": {
"bridge": {
"IPAMConfig": null,
"Links": null,
"Aliases": null,
"NetworkID": "fb9c9f61e3c225a2a6ec8bb10e691b8f0fc0fb416fd3916a998cdff221534a55",
"EndpointID": "",
"Gateway": "",
"IPAddress": "",
"IPPrefixLen": 0,
"IPv6Gateway": "",
"GlobalIPv6Address": "",
"GlobalIPv6PrefixLen": 0,
"MacAddress": "",
"DriverOpts": null,
"IPAMOperational": false
}
},
"Service": null,
"Ports": null,
"SandboxKey": "/var/run/docker/netns/d681fbde606c",
"SecondaryIPAddresses": null,
"SecondaryIPv6Addresses": null,
"IsAnonymousEndpoint": false,
"HasSwarmEndpoint": false
},
"LogPath": "/var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470-json.log",
"Name": "/nginx-demo",
"Driver": "overlay2",
"MountLabel": "",
"ProcessLabel": "",
"RestartCount": 0,
"HasBeenStartedBefore": true,
"HasBeenManuallyStopped": false,
"MountPoints": {},
"SecretReferences": null,
"ConfigReferences": null,
"AppArmorProfile": "",
"HostnamePath": "/var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470/hostname",
"HostsPath": "/var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470/hosts",
"ShmPath": "/var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470/shm",
"ResolvConfPath": "/var/lib/docker/containers/16aeecf6ed6fcc17793060ffac32315bbaa76a08eaee00062e31c74a01802470/resolv.conf",
"SeccompProfile": "",
"NoNewPrivileges": false
}
其中的config.ExposedPorts就是我们要修改的端口映射配置项
"Config": {
...
"ExposedPorts": {
"80/tcp": {}
}
...
}
和上面一样，我们将该项修改如下
"Config": {
...
"ExposedPorts": {
"80/tcp": {"HostIp": "",
"HostPort": "8081"}
}
...
}
三、重启docker服务，配置生效
最后执行docker容器重启命令systemctl start docker,启动容器之后就可以看到新增的端口映射了。
[root@localhost /]# docker ps
CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES
16aeecf6ed6f nginx "nginx -g 'daemon ..." 44 minutes ago Up 2 minutes 0.0.0.0:8081->80/tcp nginx-demo
如有疑问，可以在下面留言！
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