Bits of .NET

📝 See What Your Container is Doing

Containers run in background. docker logs shows stdout/stderr output. Debug, monitor, troubleshoot.

📝 Log Commands

# View all logs
docker logs container_name

# Follow live logs
docker logs -f container_name

# Last 100 lines
docker logs --tail 100 container_name

# Since last 30 minutes
docker logs --since 30m container_name

# Since specific time
docker logs --since "2024-01-15T10:00:00" container_name

# Until specific time
docker logs --until "2024-01-15T12:00:00" container_name

# Show timestamps
docker logs --timestamps container_name

# Show details (log driver)
docker logs --details container_name

🎯 Debugging with Logs

# Check if app started correctly
docker logs --tail 50 container_name

# Follow and filter
docker logs -f container_name | grep ERROR

# Combine with grep
docker logs container_name | grep "Exception"

# Export logs to file
docker logs container_name > app.log 2>&1

# Check specific container (with name)
docker logs web-app | head -20

# Check multiple containers
docker logs web-app | tail -20
docker logs db-app | tail -20

💡 Logging Best Practices

• Log to stdout/stderr (not files)
• Set log rotation (–log-opt max-size=10m)
• Use structured logging (JSON)
• Include timestamps
• Use log aggregation in production