# Docker – Commands

Practical Docker and Docker Compose command reference. Each block groups related commands with inline comments.

For the concepts behind these commands, see:

- [Docker / Basics](./Basics.md)

---

## 1. Images

```bash
# List local images
docker images

# Pull an image from a registry
docker pull nginx:stable

# Build an image from a Dockerfile in the current directory
docker build -t myapp:1.0 .

# Build with a custom Dockerfile
docker build -f Dockerfile.prod -t myapp:prod .

# Tag an existing image
docker tag myapp:1.0 myapp:latest

# Remove an image
docker rmi myapp:1.0

# Remove all unused images (dangling and unreferenced)
docker image prune -a
```

---

## 2. Container Lifecycle

```bash
# Run a container in detached mode
docker run -d --name myapp -p 8080:80 nginx:stable

# Run with a bind mount, environment variable, and restart policy
docker run -d \
  --name myapp \
  -v /host/data:/app/data \
  -e APP_ENV=production \
  --restart unless-stopped \
  myapp:1.0

# Start / stop / restart a container
docker start myapp
docker stop myapp
docker restart myapp

# List running containers
docker ps

# List all containers (including stopped)
docker ps -a

# Remove a stopped container
docker rm myapp

# Stop and remove in one go
docker stop myapp && docker rm myapp
```

---

## 3. Logs and Inspection

```bash
# View container logs
docker logs myapp

# Follow logs in real time
docker logs -f myapp

# Show last 50 lines
docker logs --tail 50 myapp

# Execute a command inside a running container
docker exec -it myapp bash       # interactive shell
docker exec myapp ls /app        # one-off command

# Inspect container configuration and networking
docker inspect myapp

# Show live resource usage for all running containers
docker stats
```

---

## 4. Volumes

```bash
# List volumes
docker volume ls

# Create a named volume
docker volume create mydata

# Inspect a volume (shows mount path on host)
docker volume inspect mydata

# Remove a volume
docker volume rm mydata

# Remove all unused volumes
docker volume prune
```

---

## 5. Networks

```bash
# List networks
docker network ls

# Create a user-defined bridge network
docker network create mynet

# Connect a running container to a network
docker network connect mynet myapp

# Inspect a network (shows connected containers)
docker network inspect mynet

# Remove a network
docker network rm mynet
```

---

## 6. Docker Compose

```bash
# Start all services in detached mode
docker compose up -d

# Stop and remove containers (volumes are kept)
docker compose down

# Stop and remove containers AND named volumes
docker compose down -v

# Rebuild images before starting
docker compose up -d --build

# Restart a single service
docker compose restart app

# View logs for all services
docker compose logs -f

# View logs for one service
docker compose logs -f app

# List containers for the current project
docker compose ps

# Execute a command inside a service container
docker compose exec app bash
```

---

## 7. System Cleanup

```bash
# Show disk usage by Docker objects (images, containers, volumes, cache)
docker system df

# Remove all stopped containers, unused networks, dangling images, and build cache
docker system prune

# Same but also remove unused non-dangling images
docker system prune -a
```