How to use this image

start a postgres instance

$ docker run --name some-postgres -e POSTGRES_PASSWORD=mysecretpassword -d xenit/postgres

or with docker-compose:

postgresql:
    image: xenit/postgres
    ports:
    - 5432:5432
    volumes:
    - postgres:/var/lib/postgresql/data
    environment:
    - POSTGRES_USER=my_user
    - POSTGRES_PASSWORD=my_password
    - POSTGRES_DB=my_db

This image includes EXPOSE 5432 (the postgres port), so standard container linking will make it automatically available to the linked containers. The default postgres user and database are created in the entrypoint with initdb.

The postgres database is a default database meant for use by users, utilities and third party applications.
postgresql.org/docs

connect to it from an application

$ docker run --name some-app --link some-postgres:postgres -d application-that-uses-postgres

... or via psql

$ docker run -it --link some-postgres:postgres --rm postgres sh -c 'exec psql -h "$POSTGRES_PORT_5432_TCP_ADDR" -p "$POSTGRES_PORT_5432_TCP_PORT" -U postgres'

Environment Variables

The PostgreSQL image uses several environment variables which are easy to miss. While none of the variables are required, they may significantly aid you in using the image.

POSTGRES_PASSWORD

This environment variable is recommended for you to use the PostgreSQL image. This environment variable sets the superuser password for PostgreSQL. The default superuser is defined by the POSTGRES_USER environment variable. In the above example, it is being set to "mysecretpassword".

POSTGRES_USER

This optional environment variable is used in conjunction with POSTGRES_PASSWORD to set a user and its password. This variable will create the specified user with superuser power and a database with the same name. If it is not specified, then the default user of postgres will be used.

PGDATA

This optional environment variable can be used to define another location - like a subdirectory - for the database files. The default is /var/lib/postgresql/data, but if the data volume you're using is a fs mountpoint (like with GCE persistent disks), Postgres initdb recommends a subdirectory (for example /var/lib/postgresql/data/pgdata ) be created to contain the data.

POSTGRES_DB

This optional environment variable can be used to define a different name for the default database that is created when the image is first started. If it is not specified, than the value of POSTGRES_USER will be used.

PG_BASEBACKUP_DBNAME

This optional environment variable triggers a basebackup when starting with an empty PGDATA folder. Also, it creates a recovery file and the postgres will automatically start in hot standby mode. This variable will be used as the -d (--dbname) argument for the pg_basebackup command. Example: host=masterhostname port=5432 user=replication password=hello123

PGCONF_*

You can override any property in posgresql.conf by specifying an environment variable PGCONF_{conf_key}={conf_value}. Example: PGCONF_hot_standby=on .

PGHBAREPLACE and PGHBA_*

Setting PGHBAREPLACE=true will remove the pg_hba.conf and will search for all PGHBA_* environment variables, and put the values in a clean pg_hba.conf.

Source

This image is based on github.com/docker-library/postgres and extends it with:

• pglogical
• WAL-G