Database containers for local development in Docker - Mini Project: Build & Apply

Database containers for local development

📖 Scenario: You are a developer who wants to run a database locally using Docker. This helps you test your applications without installing the database directly on your computer.

🎯 Goal: You will create a Docker command to run a PostgreSQL database container locally with a set username, password, and database name. Then, you will check if the container is running.

📋 What You'll Learn

Use the official PostgreSQL Docker image version 15

Set environment variables for POSTGRES_USER, POSTGRES_PASSWORD, and POSTGRES_DB

Map the container port 5432 to the host port 5432

Name the container 'local-postgres'

Verify the container is running using a Docker command

💡 Why This Matters

🌍 Real World

Developers often use database containers locally to avoid installing databases directly on their machines. This makes setup faster and keeps the system clean.

💼 Career

Knowing how to run and manage database containers is essential for developers and DevOps engineers to create consistent development environments and simplify testing.

1

Create the Docker run command for PostgreSQL

Write a Docker command to run a PostgreSQL container named local-postgres using the image postgres:15. Set environment variables POSTGRES_USER to devuser, POSTGRES_PASSWORD to devpass, and POSTGRES_DB to devdb. Map the container port 5432 to the host port 5432. Use the docker run command with the -d flag to run in detached mode.

Docker

# Write the docker run command to start the PostgreSQL container
# Your code here

Need a hint?

Use docker run -d --name local-postgres -e POSTGRES_USER=devuser -e POSTGRES_PASSWORD=devpass -e POSTGRES_DB=devdb -p 5432:5432 postgres:15

2

Check the running containers

Write a Docker command to list all running containers. Use the docker ps command.

Docker

docker run -d --name local-postgres -e POSTGRES_USER=devuser -e POSTGRES_PASSWORD=devpass -e POSTGRES_DB=devdb -p 5432:5432 postgres:15
# Write the command to list running containers
# Your code here

Need a hint?

Use docker ps to see running containers.

3

Filter the running containers to find your PostgreSQL container

Write a Docker command to list running containers but only show the container named local-postgres. Use docker ps with the --filter option and filter by name=local-postgres.

Docker

docker run -d --name local-postgres -e POSTGRES_USER=devuser -e POSTGRES_PASSWORD=devpass -e POSTGRES_DB=devdb -p 5432:5432 postgres:15
docker ps
# Write the command to filter running containers by name 'local-postgres'
# Your code here

Need a hint?

Use docker ps --filter "name=local-postgres" to find your container.

4

Display the container status

Write a command to show only the status of the container named local-postgres. Use docker inspect with the --format option and the Go template {{.State.Status}}.

Docker

docker run -d --name local-postgres -e POSTGRES_USER=devuser -e POSTGRES_PASSWORD=devpass -e POSTGRES_DB=devdb -p 5432:5432 postgres:15
docker ps
docker ps --filter "name=local-postgres"
# Write the command to show the status of 'local-postgres'
# Your code here

Need a hint?

Use docker inspect --format='{{.State.Status}}' local-postgres to see if the container is running.