net/http. Go has great web support in the standard library.^1

Kidding aside, I didn't think that full-fledged web frameworks (akin to Ruby-on-Rails, Flask, Spring, etc) were really a thing with Go - or at least not a super popular thing. And you should be able to pretty easily recreate the functionality of a Tomcat-like web server using the http/net library.^2

[1]: https://pkg.go.dev/net/http [2]: https://go.dev/doc/articles/wiki/