Install a local MongoDB replicaset with the 10gen APT repo (upstart). http://docs.mongodb.org/manual/tutorial/install-mongodb-on-ubuntu/

etc init mongodb-localrs.conf

start on runlevel [2345]
stop on runlevel [06]

pre-start script
  start mongodb-node replset=rs_local_a port=27017
  start mongodb-node replset=rs_local_a port=27117
  start mongodb-node replset=rs_local_a port=27217

  sleep 3
  mongo localhost:27017 /etc/mongo-initiate-localrs.js
end script

post-stop script
  stop mongodb-node replset=rs_local_a port=27017
  stop mongodb-node replset=rs_local_a port=27117
  stop mongodb-node replset=rs_local_a port=27217
end script

etc init mongodb-node.conf

instance $replset-$port


respawn
respawn limit 3 15


kill timeout 300 # wait 300s between SIGTERM and SIGKILL.

# http://www.mongodb.org/display/DOCS/Too+Many+Open+Files
# MongoDB has a hard limit of 20k connections
limit nofile 8192 8192

pre-start script
  mkdir -p /var/local/mongodb/mongodb-data-$replset-$port || true
  mkdir -p /var/local/mongodb/mongodb-log-$replset-$port || true
  chown mongodb -R /var/local/mongodb/mongodb-data-$replset-$port || true
  chown mongodb -R /var/local/mongodb/mongodb-log-$replset-$port || true
end script

script
  exec start-stop-daemon --start --quiet --chuid mongodb \
    --name mongodb-$replset-$port --exec /usr/bin/mongod -- \
    --replSet $replset --smallfiles --port $port --oplogSize 64 \
    --dbpath /var/local/mongodb/mongodb-data-$replset-$port \
    --logpath /var/local/mongodb/mongodb-log-$replset-$port/mongodb.log
end script

etc mongo-initiate-localrs.js

if (rs.status()["ok"] == 0) {
    sleep(15000);

    if(rs.status()["ok"] == 0 &&
       rs.status()["startupStatus"] == 3) {

	var host = db.serverStatus()["host"].split(":")[0];

	cfg = { _id: "rs_local_a",
		members:[
		    {_id:0,host: host+":27017"},
		    {_id:1,host: host+":27117"},
		    {_id:2,host: host+":27217"},
		]
	      };
	rs.initiate(cfg);
    }
}