Not sure if it meets all of your requirements, but what about using Crystal HTTP::Server[1] and building a fully statically linked[2] binary and deploying via a

Not sure if it meets all of your requirements, but what about using Crystal HTTP::Server[1] and building a fully statically linked[2] binary and deploying via a Docker scratch image[3] using a Multi-stage build[4]. Here's[5] an example I put together that I have running on fly.io[6]. I'm doing a redirect for root path, but it could easily be changed to serve up the contents of index.html. I use a similar deployment for a small site I created[7] to generate UUIDs. Kemal[8] also looks like a good alternative. ---- Update: Here's[9] an example also running on fly.io[10] using Kemal[8] [1] https://crystal-lang.org/api/1.11.2/HTTP/Server.html https://crystal-lang.org/api/1.11.2/HTTP/Server.html [2] https://crystal-lang.org/reference/1.11/guides/static_linking.html#fully-static-linking https://crystal-lang.org/reference/1.11/guides/static_linkin... [3] https://docs.docker.com/build/building/multi-stage/ https://docs.docker.com/build/building/multi-stage/ [4] https://hub.docker.com/_/scratch/ https://hub.docker.com/_/scratch/ [5] https://github.com/adrianlv512/minimal-server https://github.com/adrianlv512/minimal-server [6] https://minimal-server.fly.dev https://minimal-server.fly.dev [7] https://uuid-generator.org/ https://uuid-generator.org/ [8] https://kemalcr.com/ https://kemalcr.com/ [9] https://github.com/adrianlv512/minimal-server-kemal https://github.com/adrianlv512/minimal-server-kemal [10] https://minimal-server-kemal.fly.dev https://minimal-server-kemal.fly.dev