Example docker compose setup for postgres with db initialization scripts (https://github.com/docker-library/docs/tree/master/postgres#initialization-scripts)

docker-compose.yml

version: "3"

services:
  db:
    image: postgres:14
    container_name: my-postgres-14
    ports:
      - "5432:5432"
    environment:
      POSTGRES_USER: hunghoang
      POSTGRES_PASSWORD: manager
      POSTGRES_DB: postgres-internals-14
    volumes:
      - db_data:/var/lib/postgresql/
      - ./init.sql:/docker-entrypoint-initdb.d/init.sql

volumes:
  db_data:

init.sql

CREATE TABLE accounts(
	id integer PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
	client text,
	amount numeric
);

INSERT INTO accounts VALUES (1, 'alice', 1000.00), (2, 'bob', 100.00), (3, 'bob', 900.00);

CREATE ROLE readonly LOGIN PASSWORD 'readonly';

GRANT SELECT ON accounts TO readonly;