How To Run PostgreSQL In Docker

Overview

• Prerequisites
• Preparing The Files
• Running The Command

Prerequisites

You need to have docker engine installed. If you have the Desktop App for Windows or Linux you're good to go.

Preparing The Files

The docker compose file describes how an image is turned into a container. For this example I've chosen the postgres:alpine image as it saves space and memory.

The container will expose to us port 6500 from port 5432, the latter being the default for a running database.

A volume will allow us to have persistence between runs.

The container will take its credentials from the .env file located in the same directory. That's why it's important to place this file at the root of your application.

Note: Make sure to change the container_name property if you're managing multiple databases to avoid naming conflicts.

services:
  postgres:
    image: postgres:alpine
    container_name: postgres
    ports:
      - '6500:5432'
    volumes:
      - progresDB:/var/lib/postgresql/data
    env_file:
      - ./.env
volumes:
  progresDB:

The .env file should include the following enviroment variables: POSTGRES_HOST, POSTGRES_PORT, POSTGRES_USER, POSTGRES_PASSWORD, POSTGRES_DB. The .env file is usually located at the root of the application. Make sure to include it in the .gitignore file to avoid leaking sensitive information.

POSTGRES_HOST=127.0.0.1
POSTGRES_PORT=6500
POSTGRES_USER=[username]
POSTGRES_PASSWORD=[password]
POSTGRES_DB=[database_name]

DATABASE_URL="postgresql://[username]:[password]@localhost:6500/[database_name]?schema=public"

Running The Command

Finally we will run the following command to create the container. -d is shorthand for --detached which will allow us to run the container in the background and still use the command line.

docker compose up -d

Thank you for reading this far. I hope this guide helps you. Docker and PostgreSQL hold a special place in my heart!