# Using multiple databases with the official PostgreSQL Docker image

This fork merges [heliocastro:user_pass_improvements](https://github.com/heliocastro/docker-postgresql-multiple-databases/tree/user_pass_improvement) with some slight tweaks to keep the user name the same as the database name.

The [official recommendation](https://hub.docker.com/_/postgres/) 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 and each entry with database, user and password separated by double colon in `POSTGRES_MULTIPLE_DATABASES` environment variable as follows
(`docker-compose` syntax):

    myapp-postgresql:
        image: postgres:9.6.2
        volumes:
            - ../docker-postgresql-multiple-databases:/docker-entrypoint-initdb.d
        environment:
            - POSTGRES_MULTIPLE_DATABASES=db1:pwd1,db2:pwd2
            - POSTGRES_USER=myapp
            - POSTGRES_PASSWORD=
            - POSTGRES_DB=db

### By building a custom image

Clone the repository, build and push the image to your Docker repository,
for example for Google Private Repository do the following:

    docker build --tag=eu.gcr.io/your-project/postgres-multi-db .
    gcloud docker -- push eu.gcr.io/your-project/postgres-multi-db

You still need to pass the `POSTGRES_MULTIPLE_DATABASES` environment variable
to the container:

    myapp-postgresql:
        image: eu.gcr.io/your-project/postgres-multi-db
        environment:
            - POSTGRES_MULTIPLE_DATABASES=db1:pwd1,db2:pwd2
            - POSTGRES_USER=myapp
            - POSTGRES_PASSWORD=
            - POSTGRES_DB=db

### Non-standard database names

If you need to use non-standard database names (hyphens, uppercase letters etc), quote them in `POSTGRES_MULTIPLE_DATABASES`:

        environment:
            - POSTGRES_MULTIPLE_DATABASES="test-db-1:pwd1","test-db-2:pwd2"