SkyDNS/SkyDock vs docker-compose about skydock

[vimishor]

Can you give more details about the problems you encountered ?
You could post your docker-compose.yml file or at least a snippet containing skydns & skydock sections.

[IanMair]

I hit this issue as well. I can't seem to pass skydock/skydns the args they need via docker-compose. Everything works great with solely docker, but with my current docker-compose.yml (relevant bits pasted below), I get the following error in my skydock container logs, "Must specify your skydns domain". Note, I also tried passing in the args as environment variables, but that had the same issue.

skydns:
  image: crosbymichael/skydns
  hostname: skydns
  command: skydns -nameserver 8.8.8.8:53 -domain docker
  dns: 8.8.8.8:53
  ports:
   - 172.17.42.1:53:53/udp

skydock:
  image: crosbymichael/skydock
  hostname: skydock
  command: skydock -ttl 30 -environment dev -s /docker.sock -domain docker -name skydns
  volumes:
   - /var/run/docker.sock:/docker.sock

Any thoughts on solutions here?

[vimishor]

@IanMair When you use docker-compose, each service name will be made from 3 parts, separated by underscore:

• directory name in which docker-compose.yml file is found.
• name of the service, as you defined it.
• service instance number

So if you have a docker-composer.yml file with the content you just posted, in a directory named test, your skydns service will actually have a name of test_skydns_1, not skydns.

So in your skydock command, you need to replace -name skydns with -name test_skydns_1 and that should fix your issue.

[IanMair]

@vimishor Thanks for the prompt reply. I updated the -name option to elements_skydns_1 (elements is the directory name). I also figured out that the "command" options should just pass the args to skydock and skydns rather than also trying to also pass the "skydock" or "skydns" executable. Now my docker-compose.yml looks like the following

skydns:
  image: crosbymichael/skydns
  command: -nameserver 8.8.8.8:53 -domain docker
  dns: 8.8.8.8:53
  ports:
   - 172.17.42.1:53:53/udp

skydock:
  image: crosbymichael/skydock
  command: -ttl 30 -environment dev -s /docker.sock -domain docker -name elements_skydns_1
  volumes:
   - /var/run/docker.sock:/docker.sock

This works now! The only weirdness is that DNS doesn't like underscores in the hostname. It appears that my services get registered to hostnames like "skydns.dev.docker" rather than "elements_skydns_1.skydns.dev.docker". It's unclear to me if there is another subdomain that the services are getting registered to instead of "elements_skydns_1", but I'm investigating now.

[shtratos]

Have you managed to solve this?

[dizzy]

You actually get both skydns.dev.docker and elements_skydns_1.skydns.dev.docker resolving to the same IP. Check skydns startup logs for how services added, e.g.

skydns_1 | 2015/07/28 15:14:53 Added Service: {e5ea90bd5d skydns elements_skydns_1 dev 172.17.0.46 53 30 2015-07-28 15:15:23.431177323 +0000 UTC map[]}

[shtratos]

Thank you!

[jeffreyporter]

Testing this via Windows 7 and Kitematic (Alpha) just gives the error...

Must specify your skydns domain
Must specify your skydns domain

Trying to start via the "Docker Quickstart Terminal" with this command...

$ docker run -d -v /var/run/docker.sock:/docker.sock --name skydock crosbymichael/skydock -ttl 30 -environment dev -s /docker.sock -domain docker -name skydns

Gives...

invalid value "C:\Program Files\Git\var\run\docker.sock;C:\Program Files\Git\docker.sock" for flag -v: bad mode specified: \Program Files\Git\docker.sock
See 'C:\Program Files\Docker Toolbox\docker.exe run --help'.

Any suggestions would be great.

Thanks
Jeff Porter