xenmatchbox is a tool to boot Xen PV domUs by using kernel, initrd and kernel arguments from matchbox.

Currently a work-in-progress but code is tested to work on Alpine Xen 4.8 dom0 with CoreOS 1465.7.0.

Run a matchbox server with gRPC API enabled (the -rpc-address flag), which requires CA, server and client certificates present.

Tested to build with Go 1.9, with dependencies using dep.

For example:

dep ensure
GOOS=linux go build .
scp xenmatchbox user@dom0:/path/to/xenmatchbox

Remove eventual kernel, ramdisk and extra parameters and provide the bootloader as:

bootloader = '/path/to/xenmatchbox'
bootloader_args = [
  '--server', 'matchbox.foo',
  '--httpport', '8080',
  '--grpcport', '8081',
  '--ca', '/path/to/ca.crt',
  '--cert', '/path/to/client.crt',
  '--key', '/path/to/client.key',
  '--lookup', 'mac=00:01:02:03:04:05',
]

This will perform a lookup of the matchbox profile based on the MAC address 00:01:02:03:04:05. Probably all other keys used in the profile can be used for lookup.

NOTE: xl currently requires a disk to be configured for the domU to use the bootloader parameter...

The current examples in the matchbox works by using variables in the return args that are expanded by either iPXE or Grub.

Similar functionality exists in xenmatchbox. Using the text/template package, variables listed in --lookup are expanded.

Example:

"args": [
  "coreos.config.url=http://matchbox/ignition?mac={{ .mac }}"
]

With configuration as above, it should be as easy as running xl create /path/to/domu.cfg.

Note that xenmatchbox gets an output directory from xl, where it will save the kernel and initrd. Since CoreOS initrd is quite large, make sure enough space is provided. Typically this is somewhere under /run.