muslrust VS upx-action

That's isn't true, one can make fully independent static binary in rust

The winning combo that I found works great is a multistage build, using clux/muslrust to build the dependencies + the binary itself, then using a scratch image as the final stage. Depending on the complexity, the statically linked images I use range from ~9MB to ~22MB. The 9MB image was ported from an existing container that was dynamically linked, and if I remember right, the image was in the ~70-80MB range using debian:buster-slim as the final stage.

muslrust: seems to be active last commit on Oct 2, 2021. But what is the difference compared to the one above?

Oh, I remember that I use https://github.com/clux/muslrust and is there what the bug is triggered. Weirdly, running it locally not show it.

After a lot of searching I came across a Docker image which provides a clean environment for building Rust linked against musl libc. It includes curl, pq, sqlite3, and zlib, but the main one I needed was OpenSSL. This container image solved my problem and I can run using Docker locally as well as in the GitHub Action build workflow.

It is currently convenient to run this bot on Azure, but it would be trivial to move it to AWS or a generic web server. Using upx to compress the executable means the final binary with a full embedded web server is just 2.5MB. This application is so lightweight it could even run on a Raspberry Pi in the office - I'd just need to compile it for ARM.