5 Quick Docker Troubleshooting Commands You Should Know

Here are five Docker commands that have saved me hours of debugging time. Bookmark this one!

1. Follow Container Logs with Timestamps

docker logs -f --timestamps container_name

The -f flag follows the log output (like tail -f), and --timestamps adds timestamps to each line. Essential for correlating events across multiple containers.

Pro tip: Limit output with --tail:

docker logs -f --tail 100 container_name

2. Get a Shell in a Running Container

docker exec -it container_name /bin/sh

If /bin/sh doesn't work (minimal containers), try /bin/bash or ash. This lets you poke around inside the container to debug issues.

For containers that don't have a shell at all:

docker run -it --rm --pid=container:container_name --net=container:container_name alpine sh

3. Inspect Container Details

docker inspect container_name | jq '.[0].NetworkSettings.Networks'

Combined with jq, you can extract exactly what you need. Common queries:

# Get IP address
docker inspect -f '{{range.NetworkSettings.Networks}}{{.IPAddress}}{{end}}' container_name

# Get mounted volumes
docker inspect -f '{{range .Mounts}}{{.Source}} -> {{.Destination}}{{"\n"}}{{end}}' container_name

# Get environment variables
docker inspect -f '{{range .Config.Env}}{{println .}}{{end}}' container_name

4. Check Resource Usage

docker stats --no-stream

Shows CPU, memory, network, and disk I/O for all running containers. The --no-stream flag gives you a snapshot instead of real-time updates.

For a specific container with more details:

docker stats container_name

5. Clean Up Docker System

# Remove unused containers, networks, images, and optionally volumes
docker system prune -a

# See what's using disk space
docker system df

# Nuclear option - reclaim ALL space (careful!)
docker system prune -a --volumes

warning

The --volumes flag will remove named volumes not used by any container. Make sure you have backups!

Bonus: Docker Compose Specific

# Rebuild a single service without cache
docker compose build --no-cache service_name

# View logs for all services
docker compose logs -f

# Restart a single service
docker compose restart service_name

# See running containers in a compose project
docker compose ps

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