Macos Docker container连接宿主机172.17.0.1的办法

在Linux docker container里面, 如果想访问宿主机上的服务, 用 172.17.0.1 这个host即可.

今天在Mac上的 dockercontainer里面启动一个服务, 这个服务需要连我主机上的MySQL, 用 172.17.0.1 是访问不了的, Connection refused.

root@d99939cc53fc:/tmp# curl 172.17.0.1:3306
curl: (7) Failed to connect to 172.17.0.1 port 3306: Connection refused

但是看网络结构, 和Linux的一样, 也是在172.17段下的.

root@d99939cc53fc:/tmp# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default 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
2: tunl0@NONE: <NOARP> mtu 1480 qdisc noop state DOWN group default qlen 1
    link/ipip 0.0.0.0 brd 0.0.0.0
3: ip6tnl0@NONE: <NOARP> mtu 1452 qdisc noop state DOWN group default qlen 1
    link/tunnel6 :: brd ::
6: eth0@if7: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default
    link/ether 02:42:ac:11:00:02 brd ff:ff:ff:ff:ff:ff link-netnsid 0
    inet 172.17.0.2/16 brd 172.17.255.255 scope global eth0
       valid_lft forever preferred_lft forever

不得其解, Google之, 发现有个隐藏奥秘, https://stackoverflow.com/questions/38504890/docker-for-mac-1-12-0-how-to-connect-to-host-from-container 问题下有人在 Docker Community Edition 17.06.0-ce-mac18, 2017-06-28 的release notes中发现有

Add an experimental DNS name for the host: docker.for.mac.localhost

这样一条更新日志.

页面搜索docker.for.mac.localhost, 发现在 Docker Community Edition 17.12.0-ce-mac46 2018-01-09 的 release notes中发现有一条相关的更新日志

• DNS name docker.for.mac.host.internal should be used instead of docker.for.mac.localhost (still valid) for host resolution from containers, since since there is an RFC banning the use of subdomains of localhost. See https://tools.ietf.org/html/draft-west-let-localhost-be-localhost-06.

所以, 结论就是在 container 中应该用 docker.for.mac.host.internal 来访问宿主机.

于是用curl看一下端口通不通, 果然通.

root@d99939cc53fc:/tmp# curl docker.for.mac.host.internal:3306
5.7.21Bf