CIVM

A simple and stupid VM runner for CI.

Ratio

Sometimes it is required to run functional tests on different Linux distros and on different kernels. There are many complex solutions to automate this task, but civm aims to be as simple as possible.

Runtime

In the project directory (. by default) civm expects following files and dirs:

• ./configs/ -- directory with VM configs in libvirt XML format
• ./urls -- file with VM disk images urls
• ./pre.sh -- a shell script to run before VM start
• ./post.sh -- a shell script to run after VM stop

File formats and sample scripts are in the examples directory.

The main process scheme:

• collect disk image names from configs and check if they exist
• if an image is missing, download it and check md5sum
• start up to maxwid workers in parallel
• wait for the next free worker and start it with the next config
• wait until all workers are stopped

The worker process scheme:

• reset VM image to init snapshot, if exists
• mount VM image to /var/run/civm/mnt/<wid>
• run pre.sh
• sync FS, umount the image
• start VM
• wait until it stops
• mount VM image to /var/run/civm/mnt/<wid>
• run post.sh
• sync FS, umount the image

Environment variables provided by worker to scripts:

• $CIVM_WORKER_MOUNT -- VM disk mountpoint to access the root FS
• $CIVM_WORKER_NAME -- the VM name
• $CIVM_WORKER_WORKDIR -- working directory for pre/post scripts

Disk image requirements

The disk image must be in the qcow2 format and must contain init snapshot. The script automatically reverts the image to the init state every time it is launched. It should contain the only primary partition with / as the mountpoint.