IP addresses in config map are not correct on Docker for Mac

[michaelpigg]

When running on Docker for Mac, the IP address reported for the machine in the config map is not correct. The plugin appears to be reporting the IP address within the machine rather than the external IP address.

[michaelpigg]

I tried a build with the changes on feature/dockerForMacSupport and it seems to work.

[kurtkopchik]

Hi @michaelpigg, I'm glad you already found the feature/dockerForMacSupport branch! We have some more testing to do on that branch but hope to integrate it into the master branch soon for an official release. Let us know if you find any problems with it.

[stela]

Please consider merging and releasing the dockerForMacSupport branch, the exported ip:port isn't very useful with docker for mac at the moment.

However, if somebody is using Alpine Linux via some boot2docker alternative or as a host OS, won't it mis-detect it as docker for mac, which would break the hostname for those users? I guess it's not that common though.

I don't know of the "proper" way to probe for docker for mac, so I'd suggest also adding a check for docker version --format '{{.Client.Os}}' == darwin, then you know that the client is running on OS X which should significantly increase the odds it's really docker for mac. Reference: https://docs.docker.com/engine/reference/commandline/version/

Also see discussions on fixing this issue in docker for mac itself, it's a known issue:
https://forums.docker.com/t/support-tap-interface-for-direct-container-access-incl-multi-host/17835/4
https://forums.docker.com/t/ip-routing-to-container/8424

[kurtkopchik]

Hi @stela - Thanks for pinging me on this issue and providing some links with your research. I had looked into this a while back myself and came up with an approach that appears to work but didn't get around to implementing the actual change until today.

The approach I took was to additionally validate that the Server.KernelVersion ends in -moby.

See the following thread for a bit of discussion on this:
http://stackoverflow.com/questions/38223965/how-can-i-detect-if-docker-for-mac-is-installed

I have merged these changes into the master branch and published a new release:
addSbtPlugin("com.tapad" % "sbt-docker-compose" % "1.0.19")

Let me know if it works for you. Thanks again for the feedback and using the plug-in!

[stela]

Works perfectly on my Mac using the System.getProperty("containername:portnr") approach, thanks!

[kurtkopchik]

Great I'm glad that it's working as expected!