Postgres 9.6 Dockerized w/ Replication

Master/Slave Postgres Replication in 30 seconds.

• Quickstart: docker-compose up
• For production, use docker-compose, Kubernetes, Rancher, Tutum, other PaaS tooling, ... or roll your own.
• To see container environment variable requirements, see docker-compose.yml.
• To demonstrate multiple slaves:
  • docker-compose up
  • docker-compose scale pg-slave=3

Notes

• No additional replication user is setup - the postgres admin user is used. This means the superuser credentials must be identical on the master and all slaves.
• setup-replication.sh is only executed when a container's data volume is first initialized.
• REPLICATE_FROM environment variable is only used during container initialization - if the master changes after the database has been initialized, you'll need to manually adjust the recovery.conf file in the slave containers' data volume.
• Configuration:
  • PG_MAX_WAL_SENDERS 8 - Maximum number of slaves
  • PG_WAL_KEEP_SEGMENTS 32 - See http://www.postgresql.org/docs/9.6/static/runtime-config-replication.html