Logging

FTL provides access to logs from your deployed services, allowing you to monitor and troubleshoot your applications.

Basic Usage

View logs from all services:

ftl logs

Command Options

View Specific Service Logs

ftl logs [service]

Command Flags

• -f, --follow: Stream logs in real-time
• -n, --tail <lines>: Number of lines to show from the end of the logs (default is 100 if -f is used)

Examples

View All Service Logs

# Show logs from all services
ftl logs

Stream Specific Service Logs

# Stream logs from a specific service
ftl logs my-app -f

Customize Log Output

# Show last 50 lines from all services
ftl logs -n 50

# Show last 150 lines from a specific service
ftl logs my-app -n 150

Log Sources

FTL collects logs from:

1. Application Services

   • Main application containers
   • Custom service containers

2. Dependencies

   • Database containers
   • Cache services
   • Other supporting services

3. System Services

   • Nginx reverse proxy
   • SSL certificate management

Best Practices

1. Log Monitoring

   • Use -f flag during deployments
   • Monitor application startup
   • Track dependency initialization

2. Log Analysis

   • Check logs after deployments
   • Monitor for error patterns
   • Review performance issues

3. Troubleshooting

   • Start with recent logs
   • Focus on specific services
   • Use appropriate line counts

Common Issues

No Logs Available

If no logs are displayed:

• Verify the service is running
• Check service name spelling
• Ensure deployment was successful

Log Access Issues

If unable to access logs:

• Verify SSH connection
• Check server permissions
• Ensure service exists

Next Steps

1. Learn about Tunneling
2. Explore Health Checks
3. Review Zero-downtime Deployments

TIP

Use ftl logs -f during deployments to monitor the process in real-time.

Reference

• CLI Commands Reference
• Troubleshooting Guide