hosts/rx4/services/default.nix

@@ -10,6 +10,7 @@
     inputs.clients.nixosModules.syncthing
 
     outputs.nixosModules.tailscale
+    outputs.nixosModules.journald-upload
 
     ./forgejo.nix
     ./jirafeau.nix

hosts/sid/services/default.nix

@@ -9,6 +9,7 @@
     inputs.synix.nixosModules.openssh
 
     outputs.nixosModules.tailscale
+    outputs.nixosModules.journald-remote
 
     ./headscale.nix
     ./mailserver.nix

modules/nixos/common/default.nix

@@ -2,7 +2,6 @@
 
 {
   imports = [
-    # ./journald.nix # FIXME: start systemd-journal-upload.service after tailscaled
     ./nix.nix
     ./overlays.nix
 

modules/nixos/default.nix

@@ -5,6 +5,8 @@
   forgejo = import ./forgejo;
   forgejo-runner = import ./forgejo-runner;
   gnome = import ./gnome;
+  journald-remote = import ./journald-remote;
+  journald-upload = import ./journald-upload;
   monero = import ./monero;
   rsshub-oci = import ./rsshub-oci;
   tailscale = import ./tailscale;

modules/nixos/journald-remote/default.nix

@@ -0,0 +1,57 @@
+{
+  pkgs,
+  lib,
+  ...
+}:
+
+let
+  python = pkgs.python3Packages;
+
+  mcp-log-server = python.buildPythonApplication {
+    pname = "mcp-log-server";
+    version = "1.0.0";
+
+    src = ./.;
+
+    pyproject = true;
+    build-system = [ python.setuptools ];
+
+    propagatedBuildInputs = with python; [
+      fastmcp
+    ];
+
+    meta.mainProgram = "mcp-log-server";
+  };
+in
+{
+  services.journald.remote = {
+    enable = true;
+    listen = "http";
+    port = 19532;
+    settings.Remote.SplitMode = "host";
+  };
+
+  users.users.sid.extraGroups = [
+    "systemd-journal"
+    "systemd-journal-remote"
+  ];
+
+  systemd.services.mcp-log-server = {
+    description = "AI Log Access MCP Server";
+    after = [
+      "network.target"
+      "multi-user.target"
+      "systemd-journald.service"
+    ];
+    wantedBy = [ "multi-user.target" ];
+
+    script = lib.getExe mcp-log-server;
+
+    serviceConfig = {
+      User = "root";
+      Group = "root";
+      Environment = "PYTHONUNBUFFERED=1";
+      Restart = "on-failure";
+    };
+  };
+}

modules/nixos/journald-remote/pyproject.toml

@@ -0,0 +1,9 @@
+[build-system]
+requires = ["setuptools"]
+
+[project]
+name = "mcp-log-server"
+version = "1.0.0"
+
+[project.scripts]
+mcp-log-server = "server:main"

modules/nixos/journald-remote/server.py

@@ -0,0 +1,60 @@
+#!/usr/bin/env python3
+import json
+import subprocess
+from fastmcp import FastMCP
+
+mcp = FastMCP('ClusterLogQuery')
+
+@mcp.tool()
+async def search_cluster_logs(keyword: str, unit: str = '*', limit: int = 500):
+    """
+    Search centralized systemd logs collected on this server.
+
+    Args:
+        keyword: The string to search for (e.g. 'oom-kill', 'failed').
+        unit: The systemd unit to filter (e.g. 'sshd'). If '*', matches all.
+        limit: The number of log lines to return (Max 1000).
+    """
+    
+    limit = min(max(limit, 10), 1000)
+
+    cmd = [
+        'journalctl',
+        '-n', str(limit),
+        '-o', 'json',
+        '--no-pager',
+        '--directory', '/var/log/journal/remote'
+    ]
+
+    if unit != '*':
+        cmd.append(f'UNIT={unit}')
+    if keyword:
+        cmd.append(keyword)
+
+    try:
+        proc = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+        stdout, _ = proc.communicate()
+
+        logs = []
+        for line in stdout.decode('utf-8').strip().split('\n'):
+            if not line: continue
+            try:
+                log = json.loads(line)
+                logs.append({
+                    'timestamp': log.get('TIME_ISO8601'),
+                    'hostname': log.get('_HOSTNAME'),
+                    'unit': log.get('_COMM'),
+                    'message': log.get('MESSAGE')
+                })
+            except: pass
+
+        return json.dumps(logs)
+
+    except Exception as e:
+        return f'Error querying logs: {str(e)}'
+
+def main():
+    mcp.run(transport='sse', host='0.0.0.0', port=9500)
+
+if __name__ == '__main__':
+    main()

modules/nixos/journald-upload/default.nix

@@ -1,6 +1,6 @@
 {
   services.journald.upload = {
     enable = true;
-    settings.Upload.URL = "http://100.64.0.5:19532";
+    settings.Upload.URL = "http://100.64.0.6:19532";
   };
 }