WireGuard at Modal: Static IPs for serverless containers

What this post added

Introduced _vprox_, a Go-based VPN proxy leveraging WireGuard to provide static outbound IP addresses for serverless containers. Implemented WireGuard tunnel setup with TLS for key distribution, peer management with idle timeout detection using `wgctrl`, and client-side connection probing. On the worker side, implemented policy-based routing and masquerading to direct container traffic through the WireGuard tunnel, ensuring consistent source IPs for all outbound internet access.