Access host (not vm) from inside container

Docker Desktop
,
20

In one terminal:

$ docker version                                                                                                                                                                                                            08:19:09
Client:
 Version:      1.11.1
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   5604cbe
 Built:        Wed Apr 27 00:34:20 2016
 OS/Arch:      darwin/amd64

Server:
 Version:      1.11.1
 API version:  1.23
 Go version:   go1.5.4
 Git commit:   8b63c77
 Built:        Tue May 10 10:39:20 2016
 OS/Arch:      linux/amd64
$ uname -a
Darwin laptop.local 14.5.0 Darwin Kernel Version 14.5.0: Thu Apr 21 20:40:54 PDT 2016; root:xnu-2782.50.3~1/RELEASE_X86_64 x86_64
$ python -m SimpleHTTPServer
Serving HTTP on 0.0.0.0 port 8000 ...

In another terminal:

$ ifconfig
bridge100: flags=8863<UP,BROADCAST,SMART,RUNNING,SIMPLEX,MULTICAST> mtu 1500
    options=3<RXCSUM,TXCSUM>
    ether 02:9a:9d:f9:9b:64
    inet 192.168.64.1 netmask 0xffffff00 broadcast 192.168.64.255
    Configuration:
        id 0:0:0:0:0:0 priority 0 hellotime 0 fwddelay 0
        maxage 0 holdcnt 0 proto stp maxaddr 100 timeout 1200
        root id 0:0:0:0:0:0 priority 0 ifcost 0 port 0
        ipfilter disabled flags 0x2
    member: en5 flags=3<LEARNING,DISCOVER>
            ifmaxaddr 0 port 11 priority 0 path cost 0
    nd6 options=1<PERFORMNUD>
    media: autoselect
    status: active
$ docker run --rm --add-host=dh:192.168.64.1 -it alpine ping dh                                                                                                                                                             08:14:14
PING dh (192.168.64.1): 56 data bytes
64 bytes from 192.168.64.1: seq=0 ttl=63 time=0.406 ms
64 bytes from 192.168.64.1: seq=1 ttl=63 time=0.473 ms
64 bytes from 192.168.64.1: seq=2 ttl=63 time=0.400 ms
64 bytes from 192.168.64.1: seq=3 ttl=63 time=0.427 ms
^C
--- dh ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 0.400/0.426/0.473 ms
$  docker run --rm --add-host=dh:192.168.64.1 -it alpine wget http://dh:8000                                                                                                                                                 08:14:49
Connecting to dh:8000 (192.168.64.1:8000)
index.html           100% |*******************************|   178   0:00:00 ETA

I think the problem is that you are binding services to the bridge. My understanding is that the bridge is forwarding the packets onto localhost.

Anyway, I personally switched to the lo0 alias solution because:

  • I don’t have to modify the default docker settings
  • I am in control of the alias IP address which means not having to parse ifconfig output in scripts