nixos-module/defaults: add journalbeat for central logging

nix/nixos-module/defaults.nix

@@ -1,4 +1,4 @@
-{ hostName, inputs, pkgs, options, lib, ... }:
+{ hostName, inputs, pkgs, config, options, lib, ... }:
 
 {
   boot.kernelParams = [
@@ -19,6 +19,32 @@
     Storage=volatile
   '';
 
+  # central logging
+  services.journalbeat = {
+    enable = true;
+    tags = [ "zentralwerk" ];
+    extraConfig = ''
+      journalbeat.inputs:
+        # Paths that should be crawled and fetched. Possible values files and directories.
+        # When setting a directory, all journals under it are merged.
+        # When empty starts to read from local journal.
+        - paths: []
+      journalbeat:
+        seek_position: cursor
+        cursor_seek_fallback: tail
+        write_cursor_state: true
+        cursor_flush_period: 5s
+        clean_field_names: true
+        convert_to_numbers: false
+        move_metadata_to_field: journal
+        default_type: journal
+        kernel: true
+      output.logstash:
+        # Boolean flag to enable or disable the output module.
+        enabled: true
+        hosts: ["${config.site.net.serv.logging.ip4}:5044"]
+    '';
+
   nix = {
     package = pkgs.nixFlakes;
     extraOptions = "experimental-features = nix-command flakes";