docker容器映射ip（端口映射与容器互联）

当使用-P（大写的）标记时，Docker会随机映射一个49000～49900的端口到内部容器开放的网络端口；当使用-p（小写的）则可以指定要映射的端口，并且，在一个指定端口上只可以绑定一个容器。

Docker除了通过网络访问外，还提供了两个很方便的功能来满足服务访问的基本需求：

1. 允许映射容器内应用的服务端口到本地宿主主机；

1.从外部访问容器应用

从外部访问容器应用在启动容器的时候，如果不指定对应参数，在容器外部是无法通过网络来访问容器内的网络应用和服务的。当容器中运行一些网络应用，要让外部访问这些应用时，可以通过-P或-p参数来指定端口映射。当使用-P（大写的）标记时，Docker会随机映射一个49000～49900的端口到内部容器开放的网络端口；当使用-p（小写的）则可以指定要映射的端口，并且，在一个指定端口上只可以绑定一个容器。支持的格式有IP:HostPort:ContainerPort |IP::ContainerPort | HostPort:ContainerPort

2.映射所有接口地址:

$ docker run -d -p 5000:5000 resource/webapp python test.py同时也可以映射多个地址：$ docker run -d -p 5000:5000-p 3000:3000 resource/webapp python test.py

3.映射到指定地址的指定端口:

$ docker run -d -p 127.0.0.1:5000:5000 resource/webapp python test.py

4.映射到指定地址的任意端口:

$ docker run -d -p 127.0.0.1::5000 resource/webapp python test.py

5.查看映射端口配置:

使用docker port命令来查看当前映射的端口配置，同时也可以查看到绑定的地址信息$ docker port adoring_mendeleev 9000/tcp -> 0.0.0.0:9000如果想查看容器自己内部的网络和IP地址信息，可以使用docker inspect容器id:如下：docker inspect 4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140[{"Id": "4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140","Created": "2020-08-13T09:59:13.359463861Z","Path": "/portainer","Args": [],"State": {"Status": "running","Running": true,"Paused": false,"Restarting": false,"OOMKilled": false,"Dead": false,"Pid": 13948,"ExitCode": 0,"Error": "","StartedAt": "2020-08-30T08:40:01.205520719Z","FinishedAt": "2020-08-14T03:48:35.028588902Z"},"Image": "sha256:62771b0b9b0973a3e8e95595534a1240d8cfd968d30ec82dc0393ce0a256c5f3","ResolvConfPath": "/var/lib/docker/containers/4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140/resolv.conf","HostnamePath": "/var/lib/docker/containers/4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140/hostname","HostsPath": "/var/lib/docker/containers/4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140/hosts","LogPath": "/var/lib/docker/containers/4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140/4a775b0ef021e95c8968dc83d244b77261038e184e351b23f626323bcee37140-json.log","Name": "/adoring_mendeleev","RestartCount": 0,"Driver": "overlay2","Platform": "linux","MountLabel": "","ProcessLabel": "","AppArmorProfile": "","ExecIDs": null,"HostConfig": {"Binds": ["/var/run/docker.sock:/var/run/docker.sock","portainer_data:/data"],"ContainerIDFile": "","LogConfig": {"Type": "json-file","Config": {}},"NetworkMode": "default","PortBindings": {"9000/tcp": [{"HostIp": "","HostPort": "9000"}]},"RestartPolicy": {"Name": "no","MaximumRetryCount": 0},"AutoRemove": false,"VolumeDriver": "","VolumesFrom": null,"CapAdd": null,"CapDrop": null,"Capabilities": null,"Dns": [],"DnsOptions": [],"DnsSearch": [],"ExtraHosts": null,"GroupAdd": null,"IpcMode": "private","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,"DeviceRequests": null,"KernelMemory": 0,"KernelMemoryTCP": 0,"MemoryReservation": 0,"MemorySwap": 0,"MemorySwappiness": null,"OomKillDisable": false,"PidsLimit": null,"Ulimits": null,"CpuCount": 0,"CpuPercent": 0,"IOMaximumIOps": 0,"IOMaximumBandwidth": 0,"MaskedPaths": ["/proc/asound","/proc/acpi","/proc/kcore","/proc/keys","/proc/latency_stats","/proc/timer_list","/proc/timer_stats","/proc/sched_debug","/proc/scsi","/sys/firmware"],"ReadonlyPaths": ["/proc/bus","/proc/fs","/proc/irq","/proc/sys","/proc/sysrq-trigger"]},"GraphDriver": {"Data": {"LowerDir": "/var/lib/docker/overlay2/4895973fcda8eabffc390b0dfc5a0d22d1d23d7b71256eacfa4dc0c7d662f0cb-init/diff:/var/lib/docker/overlay2/469ee91de1602d2fbfe9e6c56f842a07e31361057c7258d578ef591ec625931a/diff:/var/lib/docker/overlay2/736ee2442a49627b384a170b28053add1894f67b6015760d9e03d66882ab5ea8/diff","MergedDir": "/var/lib/docker/overlay2/4895973fcda8eabffc390b0dfc5a0d22d1d23d7b71256eacfa4dc0c7d662f0cb/merged","UpperDir": "/var/lib/docker/overlay2/4895973fcda8eabffc390b0dfc5a0d22d1d23d7b71256eacfa4dc0c7d662f0cb/diff","WorkDir": "/var/lib/docker/overlay2/4895973fcda8eabffc390b0dfc5a0d22d1d23d7b71256eacfa4dc0c7d662f0cb/work"},"Name": "overlay2"},"Mounts": [{"Type": "volume","Name": "portainer_data","Source": "/var/lib/docker/volumes/portainer_data/_data","Destination": "/data","Driver": "local","Mode": "z","RW": true,"Propagation": ""},{"Type": "bind","Source": "/var/run/docker.sock","Destination": "/var/run/docker.sock","Mode": "","RW": true,"Propagation": "rprivate"}],"Config": {"Hostname": "4a775b0ef021","Domainname": "","User": "","AttachStdin": false,"AttachStdout": false,"AttachStderr": false,"ExposedPorts": {"9000/tcp": {}},"Tty": false,"OpenStdin": false,"StdinOnce": false,"Env": ["PATH=/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin"],"Cmd": null,"Image": "portainer/portainer","Volumes": {"/data": {}},"WorkingDir": "/","Entrypoint": ["/portainer"],"OnBuild": null,"Labels": {}},"NetworkSettings": {"Bridge": "","SandboxID": "136752f95fa8558d98d40336b7c2ad4362f4a554adbdd52045a6b628d148df1b","HairpinMode": false,"LinkLocalIPv6Address": "","LinkLocalIPv6PrefixLen": 0,"Ports": {"9000/tcp": [{"HostIp": "0.0.0.0","HostPort": "9000"}]},"SandboxKey": "/var/run/docker/netns/136752f95fa8","SecondaryIPAddresses": null,"SecondaryIPv6Addresses": null,"EndpointID": "b45fabb881cb54f5fda7fa1369571ff86e0a63c9c844381e4f2602be468c5679","Gateway": "172.17.0.1","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","MacAddress": "02:42:ac:11:00:02","Networks": {"bridge": {"IPAMConfig": null,"Links": null,"Aliases": null,"NetworkID": "d61dbdb3a5311f546b09cbc5e2f5b0448e14d197133e7992d1fa4c9433014396","EndpointID": "b45fabb881cb54f5fda7fa1369571ff86e0a63c9c844381e4f2602be468c5679","Gateway": "172.17.0.1","IPAddress": "172.17.0.2","IPPrefixLen": 16,"IPv6Gateway": "","GlobalIPv6Address": "","GlobalIPv6PrefixLen": 0,"MacAddress": "02:42:ac:11:00:02","DriverOpts": null}}}}

1. 2.实现多个容器间通过容器名来快速访问

容器的互联（linking）是一种让多个容器中的应用进行快速交互的方式。它会在源和接收容器之间创建连接关系，接收容器可以通过容器名快速访问到源容器，而不用指定具体的IP地址

1．自定义容器命名

连接系统依据容器的名称来执行。因此，首先需要自定义一个好记的容器命名。虽然当创建容器的时候，系统默认会分配一个名字，但自定义命名容器有两个好处：❑ 自定义的命名，比较好记，比如一个Web应用容器我们可以给它起名叫web，一目了然；❑ 当要连接其他容器时候（即便重启），也可以使用容器名而不用改变，比如连接web容器到db容器。使用--name标记可以为容器自定义命名：$ docker run -d -p 5000:5000 --name web resource/webapp python test.py容器的名称是唯一的。如果已经命名了一个叫web的容器，当你要再次使用web这个名称的时候，需要先用docker rm命令删除之前创建的同名容器在执行docker [container] run的时候如果添加--rm标记，则容器在终止后会立刻删除。注意，--rm和-d参数不能同时使用

2．容器互联

使用--link参数可以让容器之间安全地进行交互。

先创建一个新的数据库容器：$ docker run -d --name db test/mysql创建一个web容器并且连接到db容器：$ docker run -d -p 8888:8888 --name web --link db:db resource/webapp python test.py--link参数的格式为--link name:alias，其中name是要链接的容器的名称，alias是别名Docker相当于在两个互联的容器之间创建了一个虚机通道，而且不用映射它们的端口到宿主主机上。在启动db容器的时候并没有使用-p和-P标记，从而避免了暴露数据库服务端口到外部网络上。Docker通过两种方式为容器公开连接信息：❑ 更新环境变量；❑ 更新/etc/hosts文件。使用env命令来查看web容器的环境变量：