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An open-source Global Server Load Balancing (GSLB) plugin for CoreDNS. Efficient routing for VMs, bare-metal, and hybrid clouds.
Why CoreDNS-GSLB?
No Vendor Lock-In
A lightweight, open-source alternative to expensive GSLB hardware. Route users to the closest backend using GeoIP (MaxMind or custom mapping) on standard VMs and bare metal.
Not Everything Runs in Kubernetes
CoreDNS-GSLB brings advanced global server load balancing to VMs, bare-metal servers, and hybrid cloud environments.
Modern Health Checks
Supports HTTP/S, TCP, ICMP, MySQL, gRPC, and custom Lua scripting to instantly reroute traffic when a backend fails.
Prometheus Metrics
Monitor cluster health, active backends, latency, and routing decisions in real-time with built-in Prometheus metrics and dashboards.
Supported Records
Natively resolves and dynamically routes not only standard A/AAAA but also SRV, SVCB, HTTPS, TXT, and wildcard records for modern application delivery.
Backend Discovery
Automatically discovers backend endpoints from external registries like Consul, custom HTTP JSON APIs, or upstream DNS records.
Cluster Mode
Coordinate health checks and status updates across multiple cluster instances, utilizing distributed locks to eliminate redundant probing.
Offloaded Probing
Isolate health check execution from your critical DNS resolution path to optimize resolver resources, or deploy dedicated probers to monitor restricted subnets.
Where to Start?
Getting Started
Run your first failover setup with Docker Compose.
Configuration
Configure DNS zones, load balancing algorithms, and metrics.
Health Checks
Build robust healthcheck profiles for your endpoints.
REST API
Dynamically enable/disable backends via REST endpoints.
More DNS tools?
DNS-collector
Grab your DNS logs, detect anomalies, analyze traffic patterns, and finally understand exactly what's happening on your network in real-time.
DNS-tester
A comprehensive DNS testing and verification toolkit designed to validate DNS response behavior and performance under various network conditions.