#Puppet Module to manage Master and Slave servers using Postgresql.

Uses Puppetlabs-Postgresql module https://github.com/puppetlabs/puppetlabs-postgresql/

This module is ready to be used with The Foreman tool http://theforeman.org/

##Requirements

puppetlabs-Postgresql: https://github.com/puppetlabs/puppetlabs-postgresql puppetlabs-stdlib: https://github.com/puppetlabs/puppetlabs-stdlib

##Overview

This module works by sending every logged modification on the Master to the Slave, replicating the database immediately. The files modified by the module are:

/etc/postgresql/9.3/main/pg_hba.conf
/etc/postgresql/9.3/main/postgresql.conf
/var/lib/postgresql/9.3/main/recovery.conf

Setup

class { 'postgresreplication' :
  $user                = 'rep',
  $password,
  $master_IP_address,
  $slave_IP_address,
  $port                = 5432,
  $trigger_file        = undef,
}

$user

Replication user that will run on both servers. This user can only be used for replication.

$password

Replication user password.

$master_IP_address

IP address of Master.

$slave_IP_address

IP address of Slave.

$port

Port used for the replication.

$trigger_file

If this file is present on the Slave, it will act as a Master.

##Usage

Run puppet on both Master and Slave.

Allow both servers to communicate with each other by exchanging ssh keys.

On both, with postgres user, run

# ssh-keygen
# ssh-copy-id IP_address_of_the_opposite_server

Then, on Slave $ sudo service postgresql stop

Finally, on Master, replicate the initial database

# psql -c "select pg_start_backup('initial_backup');"
# rsync -cva --inplace --exclude=*pg_xlog* /var/lib/postgresql/9.3/main/ slave_IP_address:/var/lib/postgresql/9.3/main/
# psql -c "select pg_stop_backup();"

Start postgresql service on Slave and everything must be up and running.

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Adapted from: https://www.digitalocean.com/community/tutorials/how-to-set-up-master-slave-replication-on-postgresql-on-an-ubuntu-12-04-vps