Using multiple databases with the official PostgreSQL Docker image

The official recommendation for creating multiple databases is as follows:

If you would like to do additional initialization in an image derived from this one, add one or more *.sql, *.sql.gz, or *.sh scripts under /docker-entrypoint-initdb.d (creating the directory if necessary). After the entrypoint calls initdb to create the default postgres user and database, it will run any *.sql files and source any *.sh scripts found in that directory to do further initialization before starting the service.

This directory contains a script to create multiple databases using that mechanism.

Usage

By mounting a volume

Clone the repository, mount its directory as a volume into /docker-entrypoint-initdb.d and declare database names separated by commas in POSTGRES_MULTIPLE_DATABASES and POSTGRES_SCHEMAS environment variable as follows (docker-compose syntax):

myapp-postgresql:
    image: postgres:latest
    volumes:
        - ../docker-postgresql-custom-databases:/docker-entrypoint-initdb.d
    environment:
        - POSTGRES_MULTIPLE_DATABASES=<data>
        - POSTGRES_SCHEMAS=<data>
        - POSTGRES_USER=<data>
        - POSTGRES_PASSWORD=<data>

Using image

docker-compose syntax:

myapp-postgresql:
    image: nimdev/postgresql-custom-databases:latest
    environment:
        - POSTGRES_MULTIPLE_DATABASES=<data>
        - POSTGRES_SCHEMAS=<data>
        - POSTGRES_USER=<data>
        - POSTGRES_PASSWORD=<data>

Environment variables

POSTGRES_MULTIPLE_DATABASES

• Required: False

• Order: 1

• Syntax with password:

  export POSTGRES_MULTIPLE_DATABASES=DB1,User1,Pass1:DB2,User2,Pass2:DB3,User1,Pass1:DB4,User1

• Syntax without password (POSTGRES_PASSWORD will be used instead):

  export POSTGRES_MULTIPLE_DATABASES=DB1,User1:DB2,User2:DB2,User1

• Syntax without username and password (POSTGRES_PASSWORD and POSTGRES_USER will be used instead):

  export POSTGRES_MULTIPLE_DATABASES=DB1:DB1:DB2

• Password, in any part is optional and if user dosen't exist, user will be created with POSTGRES_PASSWORD as password

• User specified for databased, will be created in first occurrence with password specified in there. If password is not specified, POSTGRES_PASSWORD will be used

• For example in this example, User1 will be created with password Pass1 and other passwords (Pass2) will be skipped.

  export POSTGRES_MULTIPLE_DATABASES=DB1,User1,Pass1:DB2,User1,Pass2:DB3,User1

POSTGRES_SCHEMAS

• Required: False

• Order: 2

• Syntax with password:

  export POSTGRES_SCHEMAS=DB1,Schema1,User1,Pass1:DB1,Schema2,User2,Pass2:DB2,Schema2,User1,Pass1

• Syntax without password (POSTGRES_PASSWORD will be used instead):

  export POSTGRES_SCHEMAS=DB1,Schema1,User1:DB1,Schema2,User2:DB2,Schema2,User1

• Syntax without username and password (POSTGRES_PASSWORD and POSTGRES_USER will be used instead):

  export POSTGRES_SCHEMAS=DB1,Schema1:DB1,Schema2:DB2,Schema2

• Password, in any part is optional and if user dosen't exist, user will be created with POSTGRES_PASSWORD as password

• User specified for databased, will be created in first occurrence with password specified in there. If password is not specified, POSTGRES_PASSWORD will be used

• For example in this example, User1 will be created with password Pass1 and other passwords (Pass2) will be skipped.

  export POSTGRES_SCHEMAS=DB1,Schema1,User1,Pass1:DB1,Schema2,User1,Pass2:DB2,Schema2,User2