nixos: adding jormungandr service

nixos/modules/module-list.nix

@@ -608,6 +608,7 @@
   ./services/networking/iodine.nix
   ./services/networking/iperf3.nix
   ./services/networking/ircd-hybrid/default.nix
+  ./services/networking/jormungandr.nix
   ./services/networking/iwd.nix
   ./services/networking/keepalived/default.nix
   ./services/networking/keybase.nix

nixos/modules/services/networking/jormungandr.nix

@@ -0,0 +1,97 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.services.jormungandr;
+
+  inherit (lib) mkEnableOption mkIf mkOption;
+  inherit (lib) optionalString types;
+
+  dataDir = "/var/lib/jormungandr";
+
+  # Default settings so far, as the service matures we will
+  # move these out as separate settings
+  configSettings = {
+    storage = dataDir;
+    p2p = {
+      public_address = "/ip4/127.0.0.1/tcp/8606";
+      messages = "high";
+      blocks = "high";
+    };
+    rest = {
+      listen = "127.0.0.1:8607";
+    };
+  };
+
+  configFile = if cfg.configFile == null then
+    pkgs.writeText "jormungandr.yaml" (builtins.toJSON configSettings)
+  else cfg.configFile;
+
+in {
+
+  options = {
+
+    services.jormungandr = {
+      enable = mkEnableOption "jormungandr service";
+
+      configFile = mkOption {
+       type = types.nullOr types.path;
+       default = null;
+       example = "/var/lib/jormungandr/node.yaml";
+       description = ''
+         The path of the jormungandr blockchain configuration file in YAML format.
+         If no file is specified, a file is generated using the other options.
+       '';
+     };
+
+      secretFile = mkOption {
+       type = types.nullOr types.path;
+       default = null;
+       example = "/etc/secret/jormungandr.yaml";
+       description = ''
+         The path of the jormungandr blockchain secret node configuration file in
+         YAML format. Do not store this in nix store!
+       '';
+     };
+
+      genesisBlockHash = mkOption {
+        type = types.nullOr types.string;
+        default = null;
+        example = "d70495af81ae8600aca3e642b2427327cb6001ec4d7a0037e96a00dabed163f9";
+        description = ''
+          Set the genesis block hash (the hash of the block0) so we can retrieve
+          the genesis block (and the blockchain configuration) from the existing
+          storage or from the network.
+        '';
+      };
+
+      genesisBlockFile = mkOption {
+        type = types.nullOr types.path;
+        default = null;
+        example = "/var/lib/jormungandr/block-0.bin";
+        description = ''
+          The path of the genesis block file if we are hosting it locally.
+        '';
+      };
+
+    };
+  };
+
+  config = mkIf cfg.enable {
+
+    systemd.services.jormungandr = {
+      description = "jormungandr server";
+      wantedBy = [ "multi-user.target" ];
+      after = [ "network-online.target" ];
+      serviceConfig = {
+        DynamicUser = true;
+        StateDirectory = baseNameOf dataDir;
+        ExecStart = ''
+          ${pkgs.jormungandr}/bin/jormungandr --config ${configFile} \
+            ${optionalString (cfg.secretFile != null) " --secret ${cfg.secretFile}"} \
+            ${optionalString (cfg.genesisBlockHash != null) " --genesis-block-hash ${cfg.genesisBlockHash}"} \
+            ${optionalString (cfg.genesisBlockFile != null) " --genesis-block ${cfg.genesisBlockFile}"}
+        '';
+      };
+    };
+  };
+}