Creates multiple databases with postgresql docker image

README.me

# PostgreSQL with multiple databases created

* Just copy all these files to the folder
* Change the name of your databases, and add/remove as many DB that you need in docker-compos.yml
* docker-compose build; docker-compose up

And vuala :)

create_db.sh

#!/bin/bash

# Will create up to 50 databases
# DB_NAME_x and DB_USER_x varibles should be defined

set -e

POSTGRES="psql --username ${POSTGRES_USER} ${POSTGRES_DB}"

export END=50
export i=1; while [[ $i -le $END ]]; do
  var_db_name="DB_NAME_$i"
  var_db_user="DB_USER_$i"
  if [[ -z "${!var_db_name}" ]] || [[ -z "${!var_db_user}" ]] ; then
    break
  fi

  echo "----------------------------------"
  echo "Creating database: ${!var_db_name}"
  echo "----------------------------------"
  $POSTGRES <<EOSQL
CREATE DATABASE "${!var_db_name}" OWNER "${!var_db_user}";
EOSQL
  ((i = i + 1))
done

create_db_schemas.sh

#!/bin/bash
set -e

POSTGRES="psql --username ${POSTGRES_USER} ${POSTGRES_DB}"

echo "----------------------------------"
echo "Creating initial schema for all DBs"
echo "----------------------------------"
$POSTGRES -f /dbInit.sql

create_user.sh

#!/bin/sh
set -e

echo "The same user(${POSTGRES_USER}) and password is used for all DBs...."

dbInit.sql

SELECT 'DB Schemas here...'

docker-compose.yml

version: '3.1'

# Main DB services
# PostgresQL

services:
  sb-pg:
    build:
      context: ./
      dockerfile: Dockerfile
    container_name: my-pg
    networks:
      - my_db
    environment:
      POSTGRES_USER: my_user
      POSTGRES_DB: my_db
      POSTGRES_PASSWORD: my_pass

      DB_NAME_1: my_db_1
      DB_USER_1: my_user

      DB_NAME_2: my_db_2
      DB_USER_2: my_user
    ports:
      - 5432:5432
    volumes:
      - ../db-data/postgres:/var/lib/postgresql/data

Dockerfile

FROM postgres:12-alpine
LABEL owner="Kostya Kostyushko"

# Custom initialization scripts
COPY ./create_user.sh /docker-entrypoint-initdb.d/10-create_user.sh
COPY ./create_db.sh /docker-entrypoint-initdb.d/20-create_db.sh
COPY ./dbInit.sql /dbInit.sql
COPY ./create_db_schemas.sh /docker-entrypoint-initdb.d/20-create_db_schemas.sh