As Cloudflare Workers become an increasingly popular choice for edge computing, the need for better observability tools grows with it. Today, I’m excited to introduce Fogwatch, a powerful terminal-based log viewer that brings real-time visibility to your Cloudflare Workers deployments.
What is Fogwatch?
Fogwatch is an open-source terminal-based tool that connects to Cloudflare’s API to stream logs from your Workers in real-time. It provides a TUI (Terminal User Interface) for viewing, filtering, and analyzing log data, making it easier to debug and monitor your Workers during development and in production.
Key Features
Watch your Worker logs as they happen, with zero delay. No more refreshing dashboards or waiting for logs to propagate – see exactly what’s happening right now.
Fogwatch features a modern, vim-inspired terminal interface that feels natural to developers. Navigate through logs with familiar keybindings (j/k for scrolling, h/l for switching views), and enjoy a distraction-free monitoring experience.
The status code frequency chart at the top of the interface gives you an immediate visual understanding of your Worker’s health. Spot patterns and anomalies at a glance.
Quickly focus on what matters with built-in filters:
- Filter by status codes (2xx, 4xx, 5xx)
- Search through logs
- Filter by HTTP methods
- Adjustable sampling rates for high-traffic Workers
Configure Fogwatch your way through:
- Command-line arguments
- Environment variables
- Configuration files (fogwatch.toml)
Getting Started
Clone and build from source:
git clone https://github.com/fiberplane/fogwatch.gitcd fogwatchcargo build --releaseSet your Cloudflare credentials:
export CLOUDFLARE_API_TOKEN="your-api-token"export CLOUDFLARE_ACCOUNT_ID="your-account-id"And you’re ready to start monitoring:
./target/release/fogwatch #(or just `cargo run` if you're on a dev build)Why Fogwatch?
While Cloudflare’s dashboard provides basic logging capabilities, Fogwatch brings several advantages:
- Speed: Real-time streaming means you see logs instantly
- Efficiency: Terminal-based interface means less resource usage and faster navigation
- Developer-First: Vim-like keybindings and a clean interface make it feel natural for developers
Under the Hood
Fogwatch is built with Rust, chosen for its performance, reliability, and excellent async runtime support. The application architecture leverages several key components:
Terminal Interface
The UI is powered by ratatui, a Rust library for building rich terminal user interfaces. This gives us:
- Efficient screen updates with double buffering
- Cross-platform terminal manipulation
- Custom widgets for visualizing log data and status code charts
Real-time Processing
- Async WebSocket connections handle real-time log streaming
- Lock-free data structures ensure smooth UI updates even under heavy log volume
- Event-driven architecture separates UI rendering from log processing
The combination of Rust’s zero-cost abstractions and ratatui’s efficient rendering ensures Fogwatch stays responsive even when processing thousands of log entries per second.
What’s Next?
The roadmap for Fogwatch includes exciting features like:
- Enhanced filtering with path pattern matching and response time filters
- Expanded analytics with request rate metrics and error tracking
- Quality of life improvements like auto-reconnect and session persistence
Try It Today
Whether you’re debugging a production issue or monitoring your Workers’ performance, Fogwatch provides the visibility you need. Give it a try today and experience a better way to monitor your Cloudflare Workers.
Check out the GitHub repository to learn more or contribute to the project.