使用独立容器进行网络连接
本系列教程介绍了独立 Docker 容器的网络连接。有关使用 swarm 服务进行网络连接的信息，请参见 使用 swarm 服务进行网络连接。如果您需要详细了解 Docker 网络，请参见 概述。
本主题包含两个不同的教程。您可以在 Linux、Windows 或 Mac 上运行每个教程，但最后一个教程需要在其他位置运行第二个 Docker 主机。
使用默认桥接网络 演示了如何使用 Docker 自动为您设置的默认
bridge网络。此网络不是生产系统的最佳选择。使用用户定义的桥接网络 展示了如何创建和使用您自己的自定义桥接网络，以连接运行在同一 Docker 主机上的容器。建议在生产环境中运行的独立容器使用此方法。
虽然 overlay 网络 通常用于 swarm 服务，但您也可以将 overlay 网络用于独立容器。这包含在 使用 overlay 网络的教程 中。
使用默认桥接网络
在本示例中，您在同一 Docker 主机上启动了两个不同的 alpine 容器并进行了一些测试，以了解它们如何相互通信。您需要安装并运行 Docker。
打开一个终端窗口。在执行任何操作之前列出当前网络。如果您从未添加过网络或在此 Docker 守护程序上初始化过 swarm，则您应该看到以下内容。您可能会看到不同的网络，但至少应该看到这些网络（网络 ID 会不同）
$ docker network ls NETWORK ID NAME DRIVER SCOPE 17e324f45964 bridge bridge local 6ed54d316334 host host local 7092879f2cc8 none null local默认的
bridge网络与host和none一起列出。后两者不是完整的网络，而是用于启动直接连接到 Docker 守护程序主机网络堆栈的容器，或启动没有网络设备的容器。本教程将连接两个容器到bridge网络。启动两个运行
ash的alpine容器，ash是 Alpine 的默认 shell，而不是bash。-dit标志表示以分离模式（在后台）启动容器，并以交互式方式（能够在其中输入）启动，以及使用 TTY（这样您可以看到输入和输出）。由于您以分离模式启动它，因此您不会立即连接到容器。相反，将打印容器的 ID。由于您没有指定任何--network标志，因此容器会连接到默认的bridge网络。$ docker run -dit --name alpine1 alpine ash $ docker run -dit --name alpine2 alpine ash检查两个容器是否都已启动
$ docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 602dbf1edc81 alpine "ash" 4 seconds ago Up 3 seconds alpine2 da33b7aa74b0 alpine "ash" 17 seconds ago Up 16 seconds alpine1检查
bridge网络以查看哪些容器连接到它。$ docker network inspect bridge [ { "Name": "bridge", "Id": "17e324f459648a9baaea32b248d3884da102dde19396c25b30ec800068ce6b10", "Created": "2017-06-22T20:27:43.826654485Z", "Scope": "local", "Driver": "bridge", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "172.17.0.0/16", "Gateway": "172.17.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": { "602dbf1edc81813304b6cf0a647e65333dc6fe6ee6ed572dc0f686a3307c6a2c": { "Name": "alpine2", "EndpointID": "03b6aafb7ca4d7e531e292901b43719c0e34cc7eef565b38a6bf84acf50f38cd", "MacAddress": "02:42:ac:11:00:03", "IPv4Address": "172.17.0.3/16", "IPv6Address": "" }, "da33b7aa74b0bf3bda3ebd502d404320ca112a268aafe05b4851d1e3312ed168": { "Name": "alpine1", "EndpointID": "46c044a645d6afc42ddd7857d19e9dcfb89ad790afb5c239a35ac0af5e8a5bc5", "MacAddress": "02:42:ac:11:00:02", "IPv4Address": "172.17.0.2/16", "IPv6Address": "" } }, "Options": { "com.docker.network.bridge.default_bridge": "true", "com.docker.network.bridge.enable_icc": "true", "com.docker.network.bridge.enable_ip_masquerade": "true", "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0", "com.docker.network.bridge.name": "docker0", "com.docker.network.driver.mtu": "1500" }, "Labels": {} } ]在顶部附近，列出了有关
bridge网络的信息，包括 Docker 主机和bridge网络之间的网关的 IP 地址（172.17.0.1）。在Containers密钥下，列出了每个连接的容器以及有关其 IP 地址的信息（alpine1为172.17.0.2，alpine2为172.17.0.3）。容器正在后台运行。使用
docker attach命令连接到alpine1。$ docker attach alpine1 / #提示符更改为
#，表示您是容器中的root用户。使用ip addr show命令显示alpine1的网络接口，这些接口看起来与容器内部相同# ip addr show 1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN qlen 1 link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00 inet 127.0.0.1/8 scope host lo valid_lft forever preferred_lft forever inet6 ::1/128 scope host valid_lft forever preferred_lft forever 27: eth0@if28: <BROADCAST,MULTICAST,UP,LOWER_UP,M-DOWN> mtu 1500 qdisc noqueue state UP link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff inet 172.17.0.2/16 scope global eth0 valid_lft forever preferred_lft forever inet6 fe80::42:acff:fe11:2/64 scope link valid_lft forever preferred_lft forever第一个接口是回环设备。现在忽略它。注意，第二个接口的 IP 地址为
172.17.0.2，这与上一步中显示的alpine1的地址相同。在
alpine1中，确保您可以通过 pinggoogle.com连接到互联网。-c 2标志将命令限制为两次ping尝试。# ping -c 2 google.com PING google.com (172.217.3.174): 56 data bytes 64 bytes from 172.217.3.174: seq=0 ttl=41 time=9.841 ms 64 bytes from 172.217.3.174: seq=1 ttl=41 time=9.897 ms --- google.com ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 9.841/9.869/9.897 ms现在尝试 ping 第二个容器。首先，通过其 IP 地址
172.17.0.3ping 它# ping -c 2 172.17.0.3 PING 172.17.0.3 (172.17.0.3): 56 data bytes 64 bytes from 172.17.0.3: seq=0 ttl=64 time=0.086 ms 64 bytes from 172.17.0.3: seq=1 ttl=64 time=0.094 ms --- 172.17.0.3 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.086/0.090/0.094 ms这将成功。接下来，尝试通过容器名称 ping
alpine2容器。这将失败。# ping -c 2 alpine2 ping: bad address 'alpine2'使用分离序列
CTRL+pCTRL+q从alpine1分离，而不会停止它（按住CTRL并依次键入p和q）。如果您愿意，可以连接到alpine2并重复步骤 4、5 和 6，将alpine1替换为alpine2。停止并删除两个容器。
$ docker container stop alpine1 alpine2 $ docker container rm alpine1 alpine2
请记住，默认的 bridge 网络不建议用于生产环境。若要了解用户定义的桥接网络，请继续到 下一个教程。
使用用户定义的桥接网络
在本示例中，我们再次启动了两个 alpine 容器，但将它们连接到一个名为 alpine-net 的用户定义网络，我们已经创建了该网络。这些容器根本没有连接到默认的 bridge 网络。然后，我们启动了第三个 alpine 容器，该容器连接到 bridge 网络，但没有连接到 alpine-net，以及第四个 alpine 容器，该容器连接到两个网络。
创建
alpine-net网络。您不需要--driver bridge标志，因为它是默认标志，但本示例演示了如何指定它。$ docker network create --driver bridge alpine-net列出 Docker 的网络
$ docker network ls NETWORK ID NAME DRIVER SCOPE e9261a8c9a19 alpine-net bridge local 17e324f45964 bridge bridge local 6ed54d316334 host host local 7092879f2cc8 none null local检查
alpine-net网络。这将显示其 IP 地址以及没有容器连接到它的事实$ docker network inspect alpine-net [ { "Name": "alpine-net", "Id": "e9261a8c9a19eabf2bf1488bf5f208b99b1608f330cff585c273d39481c9b0ec", "Created": "2017-09-25T21:38:12.620046142Z", "Scope": "local", "Driver": "bridge", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": {}, "Config": [ { "Subnet": "172.18.0.0/16", "Gateway": "172.18.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": {}, "Options": {}, "Labels": {} } ]注意，此网络的网关为
172.18.0.1，与默认桥接网络的网关172.17.0.1不同。确切的 IP 地址在您的系统上可能不同。创建四个容器。注意
--network标志。您只能在docker run命令期间连接到一个网络，因此您需要使用docker network connect之后才能将alpine4连接到bridge网络。$ docker run -dit --name alpine1 --network alpine-net alpine ash $ docker run -dit --name alpine2 --network alpine-net alpine ash $ docker run -dit --name alpine3 alpine ash $ docker run -dit --name alpine4 --network alpine-net alpine ash $ docker network connect bridge alpine4验证所有容器是否正在运行
$ docker container ls CONTAINER ID IMAGE COMMAND CREATED STATUS PORTS NAMES 156849ccd902 alpine "ash" 41 seconds ago Up 41 seconds alpine4 fa1340b8d83e alpine "ash" 51 seconds ago Up 51 seconds alpine3 a535d969081e alpine "ash" About a minute ago Up About a minute alpine2 0a02c449a6e9 alpine "ash" About a minute ago Up About a minute alpine1再次检查
bridge网络和alpine-net网络$ docker network inspect bridge [ { "Name": "bridge", "Id": "17e324f459648a9baaea32b248d3884da102dde19396c25b30ec800068ce6b10", "Created": "2017-06-22T20:27:43.826654485Z", "Scope": "local", "Driver": "bridge", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": null, "Config": [ { "Subnet": "172.17.0.0/16", "Gateway": "172.17.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": { "156849ccd902b812b7d17f05d2d81532ccebe5bf788c9a79de63e12bb92fc621": { "Name": "alpine4", "EndpointID": "7277c5183f0da5148b33d05f329371fce7befc5282d2619cfb23690b2adf467d", "MacAddress": "02:42:ac:11:00:03", "IPv4Address": "172.17.0.3/16", "IPv6Address": "" }, "fa1340b8d83eef5497166951184ad3691eb48678a3664608ec448a687b047c53": { "Name": "alpine3", "EndpointID": "5ae767367dcbebc712c02d49556285e888819d4da6b69d88cd1b0d52a83af95f", "MacAddress": "02:42:ac:11:00:02", "IPv4Address": "172.17.0.2/16", "IPv6Address": "" } }, "Options": { "com.docker.network.bridge.default_bridge": "true", "com.docker.network.bridge.enable_icc": "true", "com.docker.network.bridge.enable_ip_masquerade": "true", "com.docker.network.bridge.host_binding_ipv4": "0.0.0.0", "com.docker.network.bridge.name": "docker0", "com.docker.network.driver.mtu": "1500" }, "Labels": {} } ]容器
alpine3和alpine4连接到bridge网络。$ docker network inspect alpine-net [ { "Name": "alpine-net", "Id": "e9261a8c9a19eabf2bf1488bf5f208b99b1608f330cff585c273d39481c9b0ec", "Created": "2017-09-25T21:38:12.620046142Z", "Scope": "local", "Driver": "bridge", "EnableIPv6": false, "IPAM": { "Driver": "default", "Options": {}, "Config": [ { "Subnet": "172.18.0.0/16", "Gateway": "172.18.0.1" } ] }, "Internal": false, "Attachable": false, "Containers": { "0a02c449a6e9a15113c51ab2681d72749548fb9f78fae4493e3b2e4e74199c4a": { "Name": "alpine1", "EndpointID": "c83621678eff9628f4e2d52baf82c49f974c36c05cba152db4c131e8e7a64673", "MacAddress": "02:42:ac:12:00:02", "IPv4Address": "172.18.0.2/16", "IPv6Address": "" }, "156849ccd902b812b7d17f05d2d81532ccebe5bf788c9a79de63e12bb92fc621": { "Name": "alpine4", "EndpointID": "058bc6a5e9272b532ef9a6ea6d7f3db4c37527ae2625d1cd1421580fd0731954", "MacAddress": "02:42:ac:12:00:04", "IPv4Address": "172.18.0.4/16", "IPv6Address": "" }, "a535d969081e003a149be8917631215616d9401edcb4d35d53f00e75ea1db653": { "Name": "alpine2", "EndpointID": "198f3141ccf2e7dba67bce358d7b71a07c5488e3867d8b7ad55a4c695ebb8740", "MacAddress": "02:42:ac:12:00:03", "IPv4Address": "172.18.0.3/16", "IPv6Address": "" } }, "Options": {}, "Labels": {} } ]容器
alpine1、alpine2和alpine4连接到alpine-net网络。在
alpine-net等用户定义网络上，容器不仅可以通过 IP 地址进行通信，还可以将容器名称解析为 IP 地址。此功能称为自动服务发现。让我们连接到alpine1并测试一下。alpine1应该能够将alpine2和alpine4（以及alpine1本身）解析为 IP 地址。注意
自动服务发现只能解析自定义容器名称，不能解析默认的自动生成的容器名称。
$ docker container attach alpine1 # ping -c 2 alpine2 PING alpine2 (172.18.0.3): 56 data bytes 64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.085 ms 64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.090 ms --- alpine2 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.085/0.087/0.090 ms # ping -c 2 alpine4 PING alpine4 (172.18.0.4): 56 data bytes 64 bytes from 172.18.0.4: seq=0 ttl=64 time=0.076 ms 64 bytes from 172.18.0.4: seq=1 ttl=64 time=0.091 ms --- alpine4 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.076/0.083/0.091 ms # ping -c 2 alpine1 PING alpine1 (172.18.0.2): 56 data bytes 64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.026 ms 64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.054 ms --- alpine1 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.026/0.040/0.054 ms从
alpine1开始，您应该根本无法连接到alpine3，因为它不在alpine-net网络上。# ping -c 2 alpine3 ping: bad address 'alpine3'不仅如此，您还无法通过其 IP 地址从
alpine1连接到alpine3。查看bridge网络的docker network inspect输出，找到alpine3的 IP 地址：172.17.0.2尝试 ping 它。# ping -c 2 172.17.0.2 PING 172.17.0.2 (172.17.0.2): 56 data bytes --- 172.17.0.2 ping statistics --- 2 packets transmitted, 0 packets received, 100% packet loss使用分离序列
CTRL+pCTRL+q从alpine1分离（按住CTRL并依次键入p和q）。请记住，
alpine4连接到默认的bridge网络和alpine-net。它应该能够访问所有其他容器。但是，您需要通过其 IP 地址访问alpine3。连接到它并运行测试。$ docker container attach alpine4 # ping -c 2 alpine1 PING alpine1 (172.18.0.2): 56 data bytes 64 bytes from 172.18.0.2: seq=0 ttl=64 time=0.074 ms 64 bytes from 172.18.0.2: seq=1 ttl=64 time=0.082 ms --- alpine1 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.074/0.078/0.082 ms # ping -c 2 alpine2 PING alpine2 (172.18.0.3): 56 data bytes 64 bytes from 172.18.0.3: seq=0 ttl=64 time=0.075 ms 64 bytes from 172.18.0.3: seq=1 ttl=64 time=0.080 ms --- alpine2 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.075/0.077/0.080 ms # ping -c 2 alpine3 ping: bad address 'alpine3' # ping -c 2 172.17.0.2 PING 172.17.0.2 (172.17.0.2): 56 data bytes 64 bytes from 172.17.0.2: seq=0 ttl=64 time=0.089 ms 64 bytes from 172.17.0.2: seq=1 ttl=64 time=0.075 ms --- 172.17.0.2 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.075/0.082/0.089 ms # ping -c 2 alpine4 PING alpine4 (172.18.0.4): 56 data bytes 64 bytes from 172.18.0.4: seq=0 ttl=64 time=0.033 ms 64 bytes from 172.18.0.4: seq=1 ttl=64 time=0.064 ms --- alpine4 ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 0.033/0.048/0.064 ms作为最终测试，确保您的容器都可以通过 ping
google.com连接到互联网。您已经连接到alpine4，因此首先尝试从那里进行。接下来，从alpine4分离并连接到alpine3（它只连接到bridge网络）并再次尝试。最后，连接到alpine1（它只连接到alpine-net网络）并再次尝试。# ping -c 2 google.com PING google.com (172.217.3.174): 56 data bytes 64 bytes from 172.217.3.174: seq=0 ttl=41 time=9.778 ms 64 bytes from 172.217.3.174: seq=1 ttl=41 time=9.634 ms --- google.com ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 9.634/9.706/9.778 ms CTRL+p CTRL+q $ docker container attach alpine3 # ping -c 2 google.com PING google.com (172.217.3.174): 56 data bytes 64 bytes from 172.217.3.174: seq=0 ttl=41 time=9.706 ms 64 bytes from 172.217.3.174: seq=1 ttl=41 time=9.851 ms --- google.com ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 9.706/9.778/9.851 ms CTRL+p CTRL+q $ docker container attach alpine1 # ping -c 2 google.com PING google.com (172.217.3.174): 56 data bytes 64 bytes from 172.217.3.174: seq=0 ttl=41 time=9.606 ms 64 bytes from 172.217.3.174: seq=1 ttl=41 time=9.603 ms --- google.com ping statistics --- 2 packets transmitted, 2 packets received, 0% packet loss round-trip min/avg/max = 9.603/9.604/9.606 ms CTRL+p CTRL+q停止并删除所有容器和
alpine-net网络。$ docker container stop alpine1 alpine2 alpine3 alpine4 $ docker container rm alpine1 alpine2 alpine3 alpine4 $ docker network rm alpine-net