An Ansible role for installing PostgreSQL.

• postgresql_version - PostgreSQL version (default: 9.6)
• postgresql_package_version - PostgreSQL package version (default: "9.6.*-2.pgdg14.04+1"
• postgresql_listen_addresses - Address for PostgreSQL to bind to (default: localhost)
• postgresql_port - Port for PostgreSQL to bind to (default: 5432)
• postgresql_data_directory - Default data directory (default: /var/lib/postgresql/{{ postgresql_version }}/main)
• postgresql_max_connections - Maximum number of connections (default: 100)
• postgresql_shared_buffers - Memory for shared buffers (default: 128MB)
• postgresql_work_mem - Memory for worker processes (default: 4MB)
• postgresql_log_autovacuum_min_duration - Minimum duration for logging long automatic vacuuming (default: -1)
• postgresql_log_min_duration_statement - Minimum duration for logging long queries (default: -1)
• postgresql_hba_mapping: - A mapping of PostgreSQL host-based authentication rules

This ansible role is taken mostly out of ansible-postgresql from Azavea Inc., but I stripped it down for brevity.