To generate the nix file, use either of the following commands depending on whether you're in the root dir or not:

nix run github:aksiksi/compose2nix -- --inputs machines/dragonwell/teamcity.yml --output machines/dragonwell/teamcity.nix --runtime docker

nix run github:aksiksi/compose2nix -- --inputs teamcity.yml --output teamcity.nix --runtime docker