opensource-gslb
opensource-gslb is a DNS load balancer written in Go that distributes traffic across multiple backend servers based on domain name resolution. It runs as a custom DNS server configurable via a JSON file specifying domains, records, IP pools, TTL values, and an optional upstream relay server for resolving undefined domains. Key features include wildcard record support, allowing any subdomain to be matched against a defined record set. Specific records take precedence over wildcards. The default load balancing uses simple round-robin selection, but the strategy is pluggable, enabling developers to implement custom algorithms by providing a function that selects an IP from a given list. Health checking is configurable per record at both Layer 4 and Layer 7. Layer 4 checks verify TCP port availability at a configurable frequency. Layer 7 checks perform HTTP or HTTPS requests against a specified path and host, optionally skipping SSL verification, and validate the response against an expected status code. Configur