FastAPI Docker Guide

Docker Commands

1. Build Docker Image

docker build -t fastapi .

Usage: Builds a Docker image named fastapi from the Dockerfile in the current directory. The -t flag tags the image with the specified name.

2. Clean Up System Resources

docker system prune -a

Usage: Removes all unused containers, networks, images, and optionally volumes. The -a flag removes all dangling and unused images. Use with caution as it frees up disk space.

3. List All Containers

docker ps -a

Usage: Lists all containers (running and stopped). Without -a, only running containers are shown.

4. Run Container Interactively

docker run --rm -it -p 8000:8000 fastapi bash

Usage:

• --rm: Automatically removes the container when it exits
• -it: Interactive terminal (combines -i for stdin and -t for terminal)
• -p 8000:8000: Maps port 8000 from container to host
• Starts a bash shell inside the fastapi container for debugging

5. Remove Docker Image

docker rmi fastapi

Usage: Removes the Docker image named fastapi. Make sure no containers are using this image before deletion.

6. Build Image (Alternative)

build -t fastapi .

Usage: Shorthand for building the image (note: typically requires docker prefix).

7. List All Docker Images

docker images

Usage: Displays all Docker images on your system with their repository, tag, image ID, creation time, and size.

8. Remove All Images

docker rmi $(docker images -q) -f

Usage:

• docker images -q: Lists all image IDs
• docker rmi: Removes images
• -f: Force remove even if images are in use
• Combined: Removes all Docker images forcefully. Use with caution.

9. Start Services with Docker Compose

docker compose up

Usage: Starts and runs all services defined in docker-compose.yml. Containers run in the foreground. Press Ctrl+C to stop.

10. Build and Start Services with Docker Compose

docker compose up --build

Usage: Rebuilds Docker images before starting services. Useful when you've made changes to the Dockerfile or code. Ensures services run with the latest builds.