I need a reliable SQL DB for our application and have been looking at Postgresql's streaming replication support. It seems that it's not hard to setup master/slave replication and you can use the slave as a hot standby for read-only queries. All good so far. However how do I automatically promote a slave to master when the master fails (or the slave thinks the master has failed)? I know I can write a file on the slave to make it become master but am looking for scripts et al to do that (and make sure the master stays down etc.).
Anyone know of a nice tutorial on how to do this on Ubuntu 12.04? Hosted at Hetzner (for bonus points)? Chef recipes or something?