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