Allow a container running via docker-machine to connect with Mysql or XDEBUG port on parent OSX system without using an OSX DHCP assigned ip address?

Question

I've got the following setup:

• OSX running MySQL listening on all network adaptors at port 3306
• XDEBUG enabled IDE listening on port 9000 on the base OSX system.
• docker-machine host running on the OSX system with the host ip 192.168.99.100
• A debian based docker container with a mysql client running on the docker host and HHVM running with xdebug looking to connect to some lucky remote host on port 9000.

The ip addresses change frequently on the OSX system due to being assigned via DHCP, so I want the docker container to be able to somehow be able to hit the mysql server regardless of what IP the native OSX network adaptors get assigned (without manually updating it). Also, I need a stable ip I can provide my HHVM server.ini file a remotes host for Xdebug.

With running a base system of linux this isn't an issue as the docker host and the actual native machine running docker are one-and-the-same. Also, there are several ways for a container to learn of the host's ip so the issue isn't hitting the docker host.

However, in OSX running docker-machine, the host ain't the native OSX system, but instead is a VM running in virtual box (assuming you're using the vb driver, and who the sam hill blazes isn't?).

The only thing I could think of was to port forward request on 3306 to the docker-machine host (192.168.99.100 which never changes) to the OSX's port 3306. Then have the container hit the docker-machine host for Mysql requests. IF this works, I could rinse and repeat for any port I port I need to link like xdebug on port 9000.

Does anyone know how to accomplish this or have another suggestion?

Answer 1

Figured a way out without needing to make any changes that provides a consistent ip to connect to on the base OSX system. Docker machine sets things up in such a way to make this possible.

• Docker machine creates a virtualbox VM with 2 network adaptors, one set up as host-only, the other set as NAT. Don't know why it creates 2, but
• The host-only adaptor provides the OSX an ip of 192.168.99.1 and the various VM's using it get addresses starting with 192.168.99.100. However, inside the VM network, you can't use the address 192.168.99.1 to hit ports on the parent OSX system (not sure why, but guessing host only intends to be only communication between the VMs).
• The NAT network adaptor is set so the OSX get's the ip 10.0.2.2 and the VM get's 10.0.2.15. With a NAT, you can route to the OSX system at 10.0.2.2 from both the docker host VM and containers running on the host.

Since this 10.0.2.2 address for the OSX machine doesn't change (unless you screw with the virtual box networking settings) bingo, got what I need.