From 6fcc19f0a2d02f6d5f6525ab303bab916f319977 Mon Sep 17 00:00:00 2001
From: h7x4 <h7x4@nani.wtf>
Date: Fri, 22 May 2026 09:22:23 +0900
Subject: [PATCH] base/fluentbit: init

---
 base/default.nix            |   1 +
 base/services/fluentbit.nix | 135 ++++++++++++++++++++++++++++++++++++
 2 files changed, 136 insertions(+)
 create mode 100644 base/services/fluentbit.nix

diff --git a/base/default.nix b/base/default.nix
index 82bad7d..56cbf75 100644
--- a/base/default.nix
+++ b/base/default.nix
@@ -23,6 +23,7 @@
     ./services/acme.nix
     ./services/auto-upgrade.nix
     ./services/dbus.nix
+    ./services/fluentbit.nix
     ./services/fwupd.nix
     ./services/irqbalance.nix
     ./services/journald-upload.nix
diff --git a/base/services/fluentbit.nix b/base/services/fluentbit.nix
new file mode 100644
index 0000000..caf865c
--- /dev/null
+++ b/base/services/fluentbit.nix
@@ -0,0 +1,135 @@
+{ config, lib, ... }:
+let
+  cfg = config.services.fluent-bit;
+in
+{
+  services.fluent-bit = {
+    enable = lib.mkDefault true;
+    settings = {
+      service = {
+        flush = 1;
+        log_level = "warn";
+
+        http_server = "on";
+        http_listen = "127.0.0.1";
+        http_port = 28183;
+
+        # filesystem-backed buffering so logs survives potential outages.
+        "storage.path" = "/var/lib/fluent-bit/storage";
+        "storage.sync" = "normal";
+        "storage.max_chunks_up" = 64;
+        "storage.backlog.mem_limit" = "16M";
+      };
+
+      pipeline = {
+        inputs = [{
+          name = "systemd";
+          tag = "journal.*";
+
+          db = "/var/lib/fluent-bit/journal.db";
+          read_from_tail = true;
+          strip_underscores = true;
+          lowercase = true;
+          max_entries = 1000;
+          "storage.type" = "filesystem";
+        }];
+
+        filters = [{
+          name = "modify";
+          match = "journal.*";
+          rename = [
+            "hostname host"
+            "priority level"
+            "systemd_unit unit"
+          ];
+        }] ++ (lib.mapAttrsToList (k: v: {
+          name = "modify";
+          match = "journal.*";
+          condition = "Key_value_equals level ${k}";
+          set = "level ${v}";
+        }) {
+          "7" = "debug";
+          "6" = "info";
+          "5" = "notice";
+          "4" = "warning";
+          "3" = "error";
+          "2" = "crit";
+          "1" = "alert";
+          "0" = "emergency";
+        });
+
+        outputs = [{
+          name = "loki";
+          match = "*";
+
+          host = "ildkule.pvv.ntnu.no";
+          port = 3100;
+          uri = "/loki/api/v1/push";
+          compress = "gzip";
+
+          labels = lib.concatStringsSep ", " [
+            "job=systemd-journal"
+          ];
+          label_keys = lib.concatMapStringsSep "," (k: "$" + k) [
+            "host"
+            "unit"
+            "level"
+          ];
+
+          # JSON is probably fine for now, then we just extract the keys we want with the grafana web ui
+          # line_format = "key_value";
+          # drop_single_key = true;
+
+          "storage.total_limit_size" = "256M";
+        }];
+      };
+    };
+  };
+
+  systemd.services.fluent-bit = lib.mkIf cfg.enable {
+    serviceConfig = {
+      StateDirectory = "fluent-bit";
+
+      # NOTE: This hardening might be way too strong for general purpose use, don't upstream this.
+      AmbientCapabilities = [ "" ];
+      CapabilityBoundingSet = [ "" ];
+      DeviceAllow = [ "" ];
+      LockPersonality = true;
+      # Lua JIT, maybe other things
+      MemoryDenyWriteExecute = false;
+      NoNewPrivileges = true;
+      PrivateDevices = true;
+      PrivateMounts = true;
+      PrivateTmp = true;
+      PrivateUsers = true;
+      ProtectClock = true;
+      ProtectControlGroups = true;
+      ProtectHome = true;
+      ProtectHostname = true;
+      ProtectKernelLogs = true;
+      ProtectKernelModules = true;
+      ProtectKernelTunables = true;
+      ProtectProc = "invisible";
+      ProtectSystem = "strict";
+      RestrictAddressFamilies = [
+        "AF_INET"
+        "AF_INET6"
+        "AF_UNIX"
+      ];
+      RestrictNamespaces = true;
+      RestrictRealtime = true;
+      RestrictSUIDSGID = true;
+      SystemCallArchitectures = "native";
+      SystemCallFilter = [
+        "@system-service"
+        "~@privileged"
+        "~@resources"
+      ];
+      UMask = "0077";
+
+      BindReadOnlyPaths = [
+        "/run/systemd/journal"
+      ];
+    };
+  };
+}