modules/consul-service-registry: init

modules/consul-service-registry/default.nix

@@ -0,0 +1,47 @@
+{ config, lib, ... }:
+
+with lib;
+
+let
+  cfg = config.consul;
+
+  consul = "${config.services.consul.package}/bin/consul";
+
+  consulServiceDefinition = submodule ({ name, ... }: {
+    unit = mkOption {
+      description = "Which systemd service to attach to.";
+      default = name;
+      type = types.str;
+    };
+    definition = mkOption {
+      description = "Consul service definition.";
+      type = types.attrs;
+    };
+  });
+
+  attachToService = name: conf: let
+    serviceJson = pkgs.writeText "consul-service-${name}.json" (builtins.toJSON conf.definition);
+  in {
+    name = conf.unit;
+    value = {
+      serviceConfig = {
+        ExecStartPost = "${consul} services register ${serviceJson}";
+        ExecStopPre = "${consul} services deregister ${serviceJson}";
+      };
+    };
+  };
+in
+
+{
+  options.consul = {
+    services = mkOption {
+      type = with types; attrsOf consulServiceDefinition;
+      default = {};
+    };
+  };
+
+  config = lib.mkIf (cfg.services != {}) {
+    systemd.services = mapAttrs' attachToService cfg.services;
+    warnings = optional (!config.services.consul.enable) "Consul service registrations found, but Consul agent is not enabled on this machine.";
+  };
+}

modules/default.nix

@@ -3,6 +3,7 @@ with builtins;
 let
   aspects = {
     autopatch = import ./autopatch;
+    consul-service-registry = import ./consul-service-registry;
     deploy-rs-receiver = import ./deploy-rs-receiver;
     enterprise = import ./enterprise;
     fail2ban = import ./fail2ban;
@@ -41,6 +42,7 @@ in rec {
     ];
 
     server = [
+      consul-service-registry
       deploy-rs-receiver
       fail2ban
       motd