Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

Unreleased

0.3.0 - 2025-12-21

Added

• Connection draining for graceful backend removal
  • Stop new connections while allowing existing ones to complete
  • Background watcher monitors connection counts via conntrack
  • Configurable drain timeout (default 30 seconds)
  • Callback support for drain completion notification
  • Runtime API: drain-backend!, undrain-backend!, wait-for-drain!
  • Status functions: get-drain-status, get-all-draining, draining?
  • Drain-aware weight computation integrates with health system
  • No BPF changes required (uses existing weight=0 handling)
  • Comprehensive examples in examples/connection-draining.clj

0.2.0 - 2025-12-21

Added

• TLS/SNI-based routing for layer 4 passthrough with layer 7 inspection
  • Route TLS traffic based on hostname without terminating TLS
  • XDP-level TLS ClientHello parsing with SNI extraction
  • FNV-1a 64-bit hashing for efficient BPF map lookup
  • Case-insensitive hostname matching
  • Weighted load balancing support per SNI hostname
  • Runtime SNI route management (add-sni-route!, remove-sni-route!, list-sni-routes)
  • Graceful fallback to default target when SNI not found or parsing fails
• New macros for cleaner code patterns
  • with-lb-state macro in core API for cleaner state access (replaces 25 when-let patterns)
  • when-root and root? in test utilities for root privilege checking
  • with-bpf-maps macro for automatic BPF map cleanup in tests
  • with-xdp-attached macro for automatic XDP detachment in tests
• Shared test utilities namespace (lb.test-util) for common test patterns
• Integration with bpf/with-program macro from clj-ebpf library for program lifecycle

0.1.0 - 2025-12-21

Added

• Initial release of clj-ebpf-lb
• XDP-based ingress DNAT for high-performance packet processing
• TC-based egress SNAT for return traffic handling
• Stateful connection tracking with per-CPU hash maps
• Source-based routing with LPM trie for CIDR matching
• Weighted load balancing across multiple backends (up to 8 targets per group)
• Health checking system with TCP, HTTP, and HTTPS checks
• Automatic weight redistribution when backends become unhealthy
• Gradual recovery for backends returning to healthy state
• Runtime configuration API for adding/removing proxies and routes
• Real-time statistics collection via ring buffer
• EDN-based configuration file format
• Command-line interface with multiple options
• ARM64 support with QEMU-based testing infrastructure
• GitHub Actions CI/CD pipeline
• Clojars publishing on version tags