Docker for mac 1.12.0: how to connect to host from container

Question

I've updated docker on my os x 10.10, so it's now using os x native virtualization. However, I've found it tricky to connect to my host machine from within my nginx container. I tried this:

/sbin/ip route|awk '/default/ { print $3 }'

And got the answer:

172.17.0.1

Then I used this ip in docker-compose.yml:

  extra_hosts:
    - "master:172.17.0.1" 

But nonetheless I keep getting errors:

172.17.0.1 - - [21/Jul/2016:09:33:46 +0000] "GET /api HTTP/1.1" 502 575 "-" "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_5) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36" "-" 2016/07/21 09:33:46 [error] 7#7: *1 connect() failed (111: Connection refused) while connecting to upstream, client: 172.17.0.1, server: soc-credit.ru, request: "GET /api HTTP/1.1", upstream: "http://172.17.0.5:8080/api", host: "localhost"

Please note this part: client: 172.17.0.1. Since I've made request from host machine, it proves that ip I got in first step was correct. But connection wasn't established anyway.

I want to stress out that I have a problem connecting FROM WITHIN container TO host and not vice versa.

What am I doing wrong? Thank you!

Answer 1

Had the same problem and being inexperienced in Docker and network configurations I struggled to get the various proposed solutions working. However since this update to Docker for Mac: Docker Community Edition 17.06.0-ce-mac18, 2017-06-28 (stable) I've found using the 'experimental' hostname docker.for.mac.localhost allows me to contact services running on the Mac host from within a container. Very useful for dev!