Add NixOS level service module (#38)

README.md

@@ -36,6 +36,15 @@ It is available as open source code here: [`\marlowe-ts-sdk/blob/main/packages/l
 
 The vesting contract is documented in our TS-SDK [API Reference](https://input-output-hk.github.io/marlowe-ts-sdk/modules/_marlowe_io_language_examples.vesting.html).
 
+
+### Configuration
+
+In order to configure the application your HTTP server should serve a `config.json`. To do so, create the file `public/config.json` with the following structure:
+
+```json
+{ "marloweWebServerUrl": 'https://link-to-runner-instance', "develMode": false }
+```
+
 ## The Prototype 
 
 The prototype allows you to create ₳ Token Plans over Cardano. 

flake.nix

@@ -10,6 +10,9 @@
     inherit inputs;
     repoRoot = ./.;
     systems = [ "x86_64-linux" "x86_64-darwin" ];
+    flake = {
+      nixosModules.default = import ./nix/nixos.nix inputs.self;
+    };
     outputs = import ./nix/outputs.nix;
   };
 

nix/nixos.nix

@@ -0,0 +1,65 @@
+self: { lib, config, pkgs, ... }:
+let
+  inherit (lib) mkOption types mapAttrs';
+
+  inherit (pkgs) writeTextDir symlinkJoin;
+
+  tokenPlansOptions = { name, ... }: {
+    options = {
+      domain = mkOption {
+        type = types.str;
+        default = name;
+        description = "The domain to host marlowe-token-plans";
+      };
+
+      # TODO local or remote
+      runtime-instance = mkOption {
+        type = types.str;
+        description = "The name of the runtime instance to connect to";
+      };
+
+      flake = mkOption {
+        type = types.attrs;
+        default = self;
+        description = "A Nix Flake containing the token plans application";
+      };
+    };
+  };
+
+  mkRoot = name: { runtime-instance, flake, ... }:
+    let
+      configJson = writeTextDir "config.json" (builtins.toJSON {
+        marloweWebServerUrl = "//${config.marlowe.runtimes.${runtime-instance}.domain}";
+        develMode = false;
+      });
+    in
+    symlinkJoin {
+      name = "marlowe-token-plans-${name}-root";
+      paths = [
+        flake.packages.${pkgs.system}.marlowe-token-plans
+        configJson
+      ];
+    };
+in
+{
+  options = {
+    marlowe.token-plans = mkOption {
+      type = types.attrsOf (types.submodule tokenPlansOptions);
+      default = { };
+      description = "Marlowe Token Plans instances to run";
+    };
+  };
+  config = {
+    http-services.static-sites = mapAttrs'
+      (name: tokenPlan: {
+        name = "marlowe-token-plans-${name}";
+        value = {
+          inherit (tokenPlan) domain;
+          root = mkRoot name tokenPlan;
+          index-fallback = true;
+        };
+      })
+      config.marlowe.token-plans;
+  };
+}
+

nix/outputs.nix

@@ -4,7 +4,7 @@
   {
     devShells.default = repoRoot.nix.shell;
 
-    packages.marlowe-vesting = repoRoot.nix.marlowe-vesting;
+    packages.marlowe-token-plans = repoRoot.nix.marlowe-vesting;
 
     hydraJobs.devShells.default = repoRoot.nix.shell;
     hydraJobs.marlowe-vesting = repoRoot.nix.marlowe-vesting;