VyOS is an open source fork of the last open source release of Vayatta, which turned proprietary a few years ago. We are currently using VyOS at work to set up OSPF routers in an OpenStack environment, and will soon have to spawn a very large amount of these in a proof-of-concept deployment.

This describes how we add support for OpenStack’s Configuration Drive to VyOS.

VyOS has something of an unhealthy relationship with Debian Squeeze (it is currently incompatible with newer Debian releases), and requires a Debian Squeeze installation in order to create the VyOS ISO used for deployments.

Below we will patch a post-installation script and add our own (very simple) Python-script that parses the Configuration Drive information and complies with a very small subset of what features packages like cloud-init provide. Unfortunately, cloud-init is not available for Debian Squeeze, which is the whole reason we are doing this in the first place.

Steps:

1. Install Squeeze
2. Create Python script
3. Run setup-script
4. Import ISO into Glance
5. Spawn OpenStack instance
6. Verify that it works

Prepare a little Python script for parsing the OpenStack Configuration Drive metadata:

#!/usr/bin/python
import json
import shutil

meta_data_file = open(‘/config-drive/openstack/latest/meta_data.json‘)
json_input = meta_data_file.read()

try:
  decoded = json.loads(json_input)

  for file in decoded[‘files‘]:
    print file[‘content_path‘], file[‘path‘]
    shutil.copy2(‘/config-drive/openstack‘ + file[‘content_path‘], file[‘path‘])

except (ValueError, KeyError, TypeError):
  print "JSON format or content error"

Save this as process-openstack-metadata.py. This will be baked into the ISO in the script below as/root/vyos-init.py.

Below is a script to generate a VyOS ISO with a few modifications. Most of it is straight from the VyOS wiki page How to build an ISO image. Read through it so you see what it does and save it as build-vyos-iso.sh, chmod it (chmod +x build-vyos-iso.sh) and run it.

#!/bin/bash -xe

apt-get install debian-archive-keyring

cat >> /etc/apt/sources.list <<EOF
deb http://backports.debian.org/debian-backports squeeze-backports main
EOF

apt-get update

# Get backported version of squashfs
apt-get -t squeeze-backports install squashfs-tools

apt-get install git autoconf automake dpkg-dev live-helper syslinux genisoimage

branch=hydrogen # hydrogen = stable, helium = dev

if ! test -d build-iso
then
  git clone https://github.com/vyos/build-iso.git

  cd build-iso

  git branch $branch --track origin/$branch
  git checkout $branch
else
  cd build-iso
fi

if ! test -d pkgs/vyatta-cfg-system/debian
then
  git submodule update --init pkgs/vyatta-cfg-system

  cd pkgs/vyatta-cfg-system/

  git branch $branch --track origin/$branch
  git checkout $branch
else
  cd pkgs/vyatta-cfg-system/
fi

# Reset debian/vyatta-cfg-system.postinst.in so we can patch it again
git checkout debian/vyatta-cfg-system.postinst.in

# Patch debian/vyatta-cfg-system.postinst.in
patch -p0 <<"HEREDOC"
--- debian/vyatta-cfg-system.postinst.in    2015-01-17 15:09:53.000000000 +0100
+++ debian/vyatta-cfg-system.postinst.in.patched    2015-01-17 15:11:19.000000000 +0100
@@ -143,6 +143,19 @@
 # configuration is fully applied. Any modifications done to work around
 # unfixed bugs and implement enhancements which are not complete in the Vyatta
 # system can be placed here.
+
+mkdir /config-drive
+
+mount -o ro -t iso9660 /dev/disk/by-label/config-2 /config-drive
+
+/root/vyos-init.py
+
+configure
+load /root/configuration
+commit
+save
+
+umount /config-drive
 EOF
 fi

HEREDOC

cd -

mkdir livecd/config.vyatta/chroot_local-includes/root

cp ../process-openstack-metadata.py   livecd/config.vyatta/chroot_local-includes/root/vyos-init.py

chmod +x livecd/config.vyatta/chroot_local-includes/root/vyos-init.py

aptitude install pdebuild-cross
make vyatta-cfg-system

find pkgs -name ‘vyatta-cfg-system*.deb‘ ||   (echo "pkgs/vyatta-cfg-system*.deb not found, exiting..."; exit 1)

echo python-simplejson >>   livecd/config.vyatta/chroot_local-packageslists/vyatta-extra.list

export PATH=/sbin:/usr/sbin:$PATH
autoreconf -i
./configure
make iso

ls -l livecd/binary.iso

echo Done!

If everything went well you will have an ISO at ./build-iso/livecd/binary.iso.

Upload this file into OpenStack with Glance and name it “VyOS Router”:

glance image-create --name "VyOS Router" --is-public True   --disk-format iso --container bare < ./build-iso/livecd/binary.iso

Create your own config.boot (or whatever else you want on the deployed machine):

cat > config.boot <<"EOF"
interfaces {
    ethernet eth0 {
        address dhcp
    }
    loopback lo {
    }
}
service {
    ssh {
        port 22
    }
}
system {
    login {
        user vyos {
            authentication {
                plaintext-password "demo"
            }
            level admin
        }
    }
}
EOF

Spawn an instance with a predefined flavor and our new configuration file to be included on the configuration drive:

nova boot --config-drive true --image "VyOS Router"   --flavor <flavor> --file /root/configuration=config.boot   --meta essential=false --nic net-id=<net-id> vyos

Verify that it works by logging into VyOS and check if the running configuration is the one you expect. You can start by checking if the file /root/configuration exists and if it the content is what you intended.

How to debug: