I have an mongo 2.6+ installation running ubuntu 14.04 on which 'sudo service mongod start/stop/restart' works just fine.
Out of curiosity I started looking out for 'upstart' script of mongod inside /etc/init.d and much to my confusion the init script for mongod has no mention of any mongo related activity in it.
The exact contents of mongod inside /etc/init.d/mongod are as following:
Someone please help me understand what is going on here.
What you are seeing is that mongo's init script is symlinked to /lib/init/upstart-job so that /etc/init.d/monogod start is relayed to Upstart properly. The file you pastebinned has nothing to do with how mongo is started. Look at the file /etc/init/mongod.conf for the upstart config for mongo.