Last time I tried building the beats from source I failed so this was the next best thing to get them working on NixOS ;)

Regarding the patchelf command:
Two of the four beats require patchelf to be run on them in order to work on NixOS. Seems like it is not done by default.

Last time I tried Filebeat, this compiled and was runnable:

{ fetchurl, buildGoPackage }:

buildGoPackage rec {
  name = "filebeat-${version}";
  goPackagePath = "github.com/elastic/beats";
  version = "5.1.2";
  src = fetchurl {
    url = "https://${goPackagePath}/archive/v${version}.tar.gz";
    sha256 = "1ki37sm6yj7m1ixfsb37128wagfymhh9hz61pc72j0kbpvw59mbw";
  };

  subPackages = [ "filebeat" ];
}

Unfortunately it propagates src into derivation, so requires polishing.

Though I can't offer much help I'm a light -1 on introducing more binary installs, even if that's a bit more effort. Source installs allow us to track the real build dependencies, and to apply patches or overrides later. It's also useful for reproducible builds.

For some packages we don't have a functioning build tool yet, e.g. bazel & tensorflow, or some maven packages. In this specific instance though I think all that's needed is a bit of fiddling.

E.g. I run a go project with a custom Makefile and my installer looks like this:

  buildPhase = ''
    shopt -s extglob
    mkdir -p ./src/github.com/coreos/dex
    mv !(src) ./src/github.com/coreos/dex
    GOPATH=$PWD
    cd ./src/github.com/coreos/dex
    make
  '';
  installPhase = ''
    mkdir -p $out/bin
    cp bin/dex $out/bin
  '';