MySQL / Postgres Docker Container Init DBs Example

docker-compose.yml

version: "3"

services:
  a-postgres-container:
    image: postgres:12
    ports:
      - ${DB_PORT_SOME_EXTERNAL_BIND:-5432}:5432
    environment:
      - POSTGRES_HOST=postgres
      - POSTGRES_USER=my_user
      - POSTGRES_PASSWORD=my_password
    entrypoint: sh -c "
      echo \"psql -v ON_ERROR_STOP=1 --username my_user --dbname postgres <<-EOSQL\n
      CREATE DATABASE some_app_database;\n
      GRANT ALL PRIVILEGES ON DATABASE some_app_database TO my_user;\n
      CREATE DATABASE some_app_database_test;\n
      GRANT ALL PRIVILEGES ON DATABASE some_app_database_test TO my_user;\nEOSQL\" > /docker-entrypoint-initdb.d/init-databases.sh;
      docker-entrypoint.sh postgres"

  a-mysql-container:
    image: mysql:5.7
    ports:
      - ${DB_PORT_SOME_EXTERNAL_BIND:-3306}:3306"
    environment:
      - MYSQL_USER=my_user
      - MYSQL_PASSWORD=my_password
      - MYSQL_ROOT_PASSWORD=my_password
    entrypoint:
      sh -c "
      echo 'CREATE DATABASE IF NOT EXISTS `some_app_database`; CREATE DATABASE IF NOT EXISTS `some_app_database_test`; GRANT ALL PRIVILEGES ON `some_app_database`.* TO my_user; GRANT ALL PRIVILEGES ON `some_app_database_test`.* TO my_user;' > /docker-entrypoint-initdb.d/init.sql;
      /usr/local/bin/docker-entrypoint.sh --character-set-server=utf8mb4 --collation-server=utf8mb4_unicode_ci"