Add simple Docker build for project

docker.nix

@@ -0,0 +1,23 @@
+let
+  pkgs = import <nixpkgs> { };
+  compiler-project = import ./default.nix { rustPlatform = pkgs.rustPlatform; };
+  source-code = builtins.fetchGit {
+    url = "https://gitea.vsinerva.fi/VSinerva/compiler-course.git";
+    name = "compiler-course-src";
+    ref = "main";
+  };
+in
+pkgs.dockerTools.buildImage {
+  name = "compiler-course-docker";
+  copyToRoot = pkgs.buildEnv {
+    name = "project-source";
+    paths = [ source-code ];
+    extraPrefix = "/Project_Source";
+  };
+  config = {
+    ExposedPorts = {
+      "3000/tcp" = { };
+    };
+    Cmd = [ "${compiler-project}/bin/compiler-course" ];
+  };
+}

shell.nix

@@ -15,6 +15,7 @@ pkgs.mkShell {
       rustc
       rustfmt
       clippy
+      docker
     ])
     ++ [ build-command ];
 }