Docker Build: No Space Left on Device — How to Fix It

docker system df

docker system prune -a --volumes

# Remove all build cache
docker builder prune
 
# Remove only cache older than 48 hours
docker builder prune --filter until=48h
 
# Check how much space it used
docker builder prune --dry-run

# Dangling = untagged images (intermediate build layers)
docker image prune
 
# Check first
docker image prune --dry-run

# List all images with size
docker images --format "table {{.Repository}}\t{{.Tag}}\t{{.Size}}" | sort -k3 -h -r
 
# Remove specific image
docker rmi image-name:tag
 
# Remove all images with specific name pattern
docker images -q "myapp" | xargs docker rmi

# List stopped containers
docker ps -a --filter "status=exited"
 
# Remove them
docker container prune
 
# Or be selective
docker rm $(docker ps -aq --filter "status=exited")

# List dangling volumes
docker volume ls -f dangling=true
 
# Remove them
docker volume prune
 
# Warning: volumes may contain database data!
# Check before deleting
docker volume inspect VOLUME_NAME

# Edit daemon.json
sudo nano /etc/docker/daemon.json

{
  "data-root": "/mnt/data/docker"
}

# Stop Docker, move data, restart
sudo systemctl stop docker
sudo mv /var/lib/docker /mnt/data/docker
sudo systemctl start docker

docker info | grep "Docker Root Dir"

# Check BuildKit cache
du -sh ~/.docker/buildx
 
# Clean it
docker buildx prune
 
# Or for a specific builder
docker buildx prune --builder mybuilder

- name: Free up disk space
  run: |
    docker system prune -f
    docker volume prune -f
 
- name: Build with BuildKit cache
  uses: docker/build-push-action@v5
  with:
    context: .
    push: true
    cache-from: type=gha
    cache-to: type=gha,mode=max

before_script:
  - docker system prune -f --volumes
 
build:
  script:
    - docker build -t $CI_REGISTRY_IMAGE:$CI_COMMIT_SHA .
  after_script:
    - docker system prune -f

# Before: 1.2GB image
FROM node:20
WORKDIR /app
COPY . .
RUN npm install
RUN npm run build
 
# After: ~200MB image with multi-stage
FROM node:20-alpine AS builder
WORKDIR /app
COPY package*.json ./
RUN npm ci
COPY . .
RUN npm run build
 
FROM node:20-alpine AS runner
WORKDIR /app
COPY --from=builder /app/dist ./dist
COPY --from=builder /app/node_modules ./node_modules
CMD ["node", "dist/index.js"]

# Add to crontab (crontab -e)
# Run docker cleanup every Sunday at 2am
0 2 * * 0 docker system prune -f --filter "until=168h" >> /var/log/docker-cleanup.log 2>&1