ansible-postgresql-barman-playground

Playground environment for PostgreSQL and Barman that uses Vagrant and Ansible.

Requirements

• Vagrant
• VirtualBox
• pyenv
• Ansible

Developed and tested on Linux and Mac OS X with Ansible 2.8.5, VirtualBox 6, and Vagrant 2.2.5.

On Linux you can install them using your default package manager. On OS X, they can be installed using homebrew:

brew install pyenv pyenv-virtualenv
brew cask install virtualbox vagrant

Installing Ansible using pyenv

To install Python 3 on your system using pyenv, follow the instructions you find on the pyenv and pyenv-virtualenv projects.

A typical installation process (assuming 3.7.4 is the latest stable version) will be similar to:

pyenv install 3.7.4
pyenv virtualenv 3.7.4 pg-playground
pyenv local pg-playground
pip install -r requirements.txt

Hosts and inventory

There is a Vagrantfile present in this repository, which is used to quickly deploy 4 VMs, that are then used as target hosts for the playbook. So, as listed in the Requiriments section above, Vagrant and Virtualbox are expected to be already installed and working on your computer before running the playbook.

Running vagrant up will create the four VMs: paul, john, george, and ringo. Yes, you've probably already heard about those guys. ;) These VM's are already listed in the inventory file at inventory/inventory.ini.

You can use the file ssh_config, located in the root of this repository, to be able to acces the VMs using their specific hostnames instead of their IP addresses if you prefer.

Running the playbook

The playbook can be run as any Ansible playbook:

ansible-playbook pg_playground.yml

In case you want to run the playbook only on some of the hosts, you can use -l (--limit) to specify them:

ansible-playbook pg_playground.yml -l paul,ringo

By default, when running this complete, you will have 2 PostgreSQL masters and 2 Barman server up and running independently. Communication through SSH should already be working between the servers, so you can start your experiments, for example:

• setting one of the masters as a standby and implementing streaming replication between them
• configuring barman to be the backup manager of your new cluster
• pointing the standby to recover WAL files from barman, to be extra sure WALs will always be found
• set the other barman server as a secondary backup server, having another layer of redundancy
• etc, etc, etc...

We hope you have fun!