Creating cross-platform portable Virtual Machines with Docker

1. create a docker virtualbox machine and connect to it

   docker-machine create dbms
   eval "$(docker-machine env dbms)"
   

2. build the docker image

   docker build --rm --tag albert/dbms:current .
   

3. modify the machine to start the docker image at startup

   docker-machine ssh dbms
   vi /mnt/sda1/var/lib/boot2docker/bootlocal.sh
   

   with content

   #!/bin/sh
      
   # wait until docker has been started
   while ! docker version; do sleep 1; done
      
   docker run --network=host albert/dbms:current
   

4. make the startup script executable with chmod a+x /mnt/sda1/var/lib/boot2docker/bootlocal.sh.

5. convert the boot2docker iso file to the vdi format.

   VBoxManage convertdd ~/.docker/machine/cache/boot2docker.iso ~/.docker/machine/cache/boot2docker.vdi --format VDI
   

   This step is required since VirtualBox does not include .iso files in .ova archives and without the file your machine does not boot.

6. Setup port forwarding, to expose services to localhost:
   • Open the VM network settings in VirtualBox
   • Choose Advanced and open the Port Forwarding dialog
   • Setup the relevant port forwarding rules with host IP 127.0.0.1
7. finalize and export
   • open the created virtual machine in VirtualBox
   • open the machine’s Settings > Storage and
     • delete the Optical Drive in the Storage tree
     • select Add Hard Disk > Choose existing disk and choose the vdi file created above (~/.docker/machine/cache/boot2docker.vdi).
   • use File > Export Appliance to export the virtual machine

Literature

• VirtualBox Docker Machine Howto
• boot2docer FAQ on local customizations