diskimage-builder/elements/os-svc-install/bin/os-svc-daemon

#!/bin/bash
set -eu


function install_upstart {
  local name=$1
  local user=$2
  local cmd=$3
  shift; shift; shift
  local args=$*
  cat > /etc/init/$name.conf <<EOF
start on runlevel [2345]
stop on runlevel [016]

pre-start script
  mkdir -p /var/run/$user
  chown -R $user:$user /var/run/$user
end script

respawn

script
  exec sudo -u $user /opt/stack/venvs/$user/bin/$cmd $args
end script
EOF
}

if [ $# -lt 4 ]; then
  echo "Usage: os-svc-daemon DAEMON_NAME USER COMMAND [ARG[ARG[...]]]"
  exit 1
fi

# TODO: check what system we are on, and install
#       systemv instead, if appropriate.
install_upstart $*