PostgreSQL 9.6 image, for supplying PostgreSQL within a Kubernetes stack.
  Includes all of "contrib", but does not include PostGIS or any automated replication management.
  
  Volumes:
  pg-config: usually mapped to /etc/postgresql/, contains the configuration files for PostgreSQL, 
    including postgresql.conf and pg_hba.conf. Read-only within the container.  
    Should map to local storage.
  pg-data: usually mapped to /var/lib/pgsql/data, contains database data.  Should be stored in 
    a persistent volume or network storage of some kind.  Requires high-throughput, read-write storage.
  
  Ports:
  5432: the PostgreSQL data port using the pgsql protocol.
  
  Documentation:
  See https://www.postgresql.org/docs/9.6/static/index.html
  
  Requirements:
  This is a transactional database, and requires 256MB of RAM and at 
  least one dedicated core.  If heavily used, can require much greater system resources.
  
  Configuration:
  Sample postgresql.conf and pg_hba.conf files are supplied in the image.  For further documentation, 
    please see the PostgreSQL docs.  Note that these files must be readable by the "postgres" user 
    inside the container.
  The database system is initialized with the admin user/password of postgres/postgres.  If you wish
    to override this, supply the ENV vars ADMIN_USER and ADMIN_PASS inside the container at initialization time.