containerfile

{ pkgs ? import <nixpkgs> { system = "aarch64-linux"; } }:

let
  # Nasz skrypt Pythona (zamiast pliku app.py)
  myApp = pkgs.writeScriptBin "app" ''
    #!${pkgs.python3}/bin/python
    import socket
    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server.bind(('0.0.0.0', 8080))
    server.listen(1)
    print("Nasluchuje...")
    while True:
        conn, addr = server.accept()
        conn.sendall(b"Hello z Nix Distroless!\n")
        conn.close()
  '';

in
pkgs.dockerTools.buildLayeredImage {
  name = "nix-python-distroless";
  tag = "latest";

  # Co ma się znaleźć w kontenerze. Zależności (np. Python) Nix wyliczy sam!
  contents = [ myApp ];

  config = {
    Cmd = [ "${myApp}/bin/app" ];
    ExposedPorts = {
      "8080/tcp" = {};
    };
  };
}