This is a snippet of dockerized PostgreSQL with support for many databases in a single instance and replication to slave.
Replication can be helpfull for easy backup creation without stopping of master.
The source article about dockerized PostgreSQL with replication is here.
List of defined databases is presented in the environment section in the variable DATABASES.
environment:
- DATABASES=db1,db2
New databases can be added later to this list.
Databases will be created with an user and password same as database name.