Add common dev environment in Nix

flake.nix

@@ -0,0 +1,27 @@
+{
+  description = "Tinyquiz – an open source online quiz platform";
+
+  inputs.nixpkgs.url = "github:NixOS/nixpkgs/nixos-20.09";
+
+  outputs = { self, nixpkgs }:
+  let
+    pkgs = nixpkgs.legacyPackages.x86_64-linux;
+  in
+    {
+      defaultPackage.x86_64-linux = self.packages.x86_64-linux.tinyquiz;
+      packages.x86_64-linux.tinyquiz = pkgs.hello; # TODO
+      packages.x86_64-linux.dev = pkgs.writeShellScriptBin "dev" ''
+        echo "This dev script must be run from the project root, otherwise unexpected behavior might occur."
+        read -p "Are you in the right directory and shall I continue? (y/n): " ack
+
+        if [ "$ack" != y ]; then exit 1; fi
+
+        unset GOROOT # Use the one bundled into the binary. I don't currently know who sets this to the wrong one
+
+        '${pkgs.findutils}/bin/find' cmd pkg ui/html | '${pkgs.entr}/bin/entr' -dr '${pkgs.go_1_14}/bin/go' run ./cmd/web
+      '';
+      packages.x86_64-linux.devDb = pkgs.writeShellScriptBin "devDb" ''
+        '${pkgs.postgresql}/bin/postgres' -D .pg-data -k "$PWD/.pg-sockets" #-c listen_addresses="" # Goland does not support connecting over socket
+      '';
+    };
+}