REX-Ray on Barge with Vagrant

REX-Ray allows us to create and attach a VMDK (Virtual Machine Disk) dynamically with VirtualBox as a persistent volume for a container.

This shows how to use REX-Ray on Barge with Vagrant instantly.

It's inspired by

• Discovering Docker Volume Plugins and Applications with VirtualBox | EMC {code} – Blog
• Volume Plugins with Docker Toolbox and Boot2Docker | EMC {code} – Blog

Please read them for further details.

Requirements

• VirtualBox
• Vagrant
• vagrant-triggers It's used to start/stop vboxwebsrv automatically.
  I have tested it on Mac OSX, so you may need to modify Vagrantfile for the other platforms.

Boot up

$ vagrant up

That's it.

A sample use case

Create a volume with REX-Ray

$ docker volume create --driver=rexray --name=mysql --opt=size=10
mysql
$ docker volume ls
DRIVER              VOLUME NAME
rexray              barge-packer-disk1.vmdk
rexray              mysql
$ ls -l "$HOME/VirtualBox Volumes"
total 2688
-rw-------  1 ailispaw  staff   1.3M Jun  9 09:55 mysql

$HOME/VirtualBox Volumes is defined in assets/config.yml. You can change the location anywhere you want.

Run a MariaDB container with the volume

$ docker run -d --volume-driver=rexray -e MYSQL_ROOT_PASSWORD=test -v mysql:/var/lib/mysql -p 3306:3306 --name mariadb mariadb
$ docker exec mariadb ls -l /var/lib/mysql
total 110644
-rw-rw---- 1 mysql mysql    16384 Jun  9 15:02 aria_log.00000001
-rw-rw---- 1 mysql mysql       52 Jun  9 15:02 aria_log_control
-rw-rw---- 1 mysql mysql 50331648 Jun  9 16:04 ib_logfile0
-rw-rw---- 1 mysql mysql 50331648 Jun  9 15:00 ib_logfile1
-rw-rw---- 1 mysql mysql 12582912 Jun  9 16:04 ibdata1
-rw-rw---- 1 mysql mysql        0 Jun  9 15:00 multi-master.info
drwx------ 2 mysql mysql     4096 Jun  9 15:00 mysql
drwx------ 2 mysql mysql     4096 Jun  9 15:00 performance_schema
-rw-rw---- 1 mysql mysql    24576 Jun  9 16:04 tc.log

Check the contents of the volume

$ docker run --rm --volume-driver=rexray -v mysql:/mysql busybox ls -l /mysql
total 110644
-rw-rw----    1 999      999          16384 Jun  9 15:02 aria_log.00000001
-rw-rw----    1 999      999             52 Jun  9 15:02 aria_log_control
-rw-rw----    1 999      999       50331648 Jun  9 16:04 ib_logfile0
-rw-rw----    1 999      999       50331648 Jun  9 15:00 ib_logfile1
-rw-rw----    1 999      999       12582912 Jun  9 16:04 ibdata1
-rw-rw----    1 999      999              0 Jun  9 15:00 multi-master.info
drwx------    2 999      999           4096 Jun  9 15:00 mysql
drwx------    2 999      999           4096 Jun  9 15:00 performance_schema
-rw-rw----    1 999      999          24576 Jun  9 16:04 tc.log

Notes

• To dettach the VMDK(volume) from the VM, stop all containers with the volume. It will just dettach the VMDK, not remove from your local disk. See also Ignore Used Count option.

• docker volume rm <volume> will remove the volume from the list of Docker volumes and the VMDK from your local disk as well. You can set Disable Remove option to disable it.

• The VMDK(volume) will be removed on vagrant destoroy unless you stop containers with the volume in advance of it, because vagrant destoroy will remove all attached virtual disks in the VM.

• The VMDK(volume) can be re-used only while VBoxSVC daemon is up. You can see the VMDK in the VirtualBox Media Manager and the volume in the list of Docker volumes. Otherwise VirtualBox will release the VMDK and it won't be re-attached, and you can't use the volume again. H'm.