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.internalshould be used instead ofdocker.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