feat(netdata): add netdata module and nginx wrapper

global/netdata/default.nix

@@ -0,0 +1,52 @@
+{ pkgs
+, lib
+, config
+, ... }: with lib; let
+  cfg = config.global.netdata;
+in {
+  options.global.netdata = {
+    enable = mkEnableOption "netdata";
+    host = mkOption {
+      type = with types; str;
+      default = "localhost";
+      description = "hostname of netdata web interface";
+    };
+    addSSL = mkEnableOption "add SSL to netdata proxy";
+    useACMEHost = mkOption {
+      type = with types; nullOr str;
+      default = null;
+      description = "existing acme host";
+    };
+    basicAuthFile = mkOption {
+      type = with types; nullOr path;
+      default = "/nix/persist/secret/netdata";
+      description = "path to passwd file";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.netdata = {
+      enable = true;
+      config = {
+        global = {
+          "error log" = "syslog";
+          "access log" = "none";
+          "debug log" = "syslog";
+        };
+        web."bind to" = "unix:/var/run/netdata/netdata.sock";
+      };
+    };
+
+    users.users.netdata.uid = 287;
+    users.groups.netdata.gid = 287;
+
+    services.nginx.enable = mkDefault true;
+    services.nginx.virtualHosts.${cfg.host} = {
+      inherit (cfg) addSSL useACMEHost basicAuthFile;
+      locations."/".proxyPass = "http://unix:/var/run/netdata/netdata.sock";
+    };
+    users.users.nginx.extraGroups = [ "netdata" ];
+
+    environment.persistence."/nix/persist/fhs".directories = [ "/var/lib/netdata" ];
+  };
+}