Template for bootstrapping a pristine Ubuntu 12.04 node on Rackspace Cloud far enough that I can then bootstrap with puppet 3.0.x and a sensible Ruby install.

rackspace-bootstrap.sh

#!/bin/sh -e

export DEBIAN_FRONTEND=noninteractive

HOSTNAME=${1}
DOMAINNAME=${2}
PUPPET_MANIFEST=${3}
PUPPETMASTER_IP=${4}
FQDN=${HOSTNAME}.${DOMAINNAME}

# Set the hostname
echo ${FQDN} > /etc/hostname
hostname ${FQDN}
domainname ${DOMAINNAME}

echo '127.0.0.1 localhost' > /etc/hosts
echo "127.0.1.1 ${HOSTNAME} ${FQDN}" >> /etc/hosts

# Restart syslog so it starts logging with the right hostname early on.
service rsyslog restart

if ! grep 'puppet' /etc/hosts >/dev/null 2>&1; then
  if [ ! -z "${PUPPETMASTER_IP}" ]; then
    echo "${PUPPETMASTER_IP} puppet.${DOMAINNAME} puppet" >> /etc/hosts
  fi
fi

apt-get update -qq
apt-get autoremove --purge -qq -y puppet-common puppet
apt-get dist-upgrade -qq -y

# Easiest way to add PPA repos, along with their PGP keys
if [ ! -f /usr/bin/add-apt-repository ]; then
  apt-get install -y -qq python-software-properties
fi

# Recent build of Ruby 1.8.7 (REE), 1.9 and a way for them to happily coexist.
if [ ! -f /etc/apt/sources.list.d/brightbox-ruby-ng-experimental-precise.list ]; then
  add-apt-repository -y ppa:brightbox/ruby-ng-experimental
fi

# Of course, we have to do the puppet labs one manually...
if [ ! -f /etc/apt/sources.list.d/puppetlabs.list ]; then
  curl -s http://apt.puppetlabs.com/pubkey.gpg | apt-key  add -
  cat > /etc/apt/sources.list.d/puppetlabs.list <<EOF
deb http://apt.puppetlabs.com/ precise main dependencies
deb-src http://apt.puppetlabs.com/ precise main dependencies
EOF
fi

apt-get update -qq
apt-get install -qq -y ruby1.8 puppet git

mkdir -p ~/.ssh
cat > ~/.ssh/id_rsa <<EOF
@@PUPPET_DEPLOY_KEY@@
EOF

chmod -R go-rwx ~/.ssh

eval $(ssh-agent)
trap "kill ${SSH_AGENT_PID}" EXIT

mkdir -p /tmp/puppet-bootstrap
cd /tmp/puppet-bootstrap

ssh-keyscan github.com >> ~/.ssh/known_hosts

git clone -q @@PUPPET_REPO@@ puppet

cd puppet
puppet apply --modulepath=`pwd`/modules --manifestdir=`pwd`/manifests `pwd`/manifests/bootstrap/${PUPPET_MANIFEST}.pp

shutdown -r now