From 22bf25715e2298fcaf707d47ffdfdc3075790b74 Mon Sep 17 00:00:00 2001
From: clerie <git@clerie.de>
Date: Tue, 23 May 2023 20:18:40 +0200
Subject: [PATCH] modules/backup: expose last backup time to monitoring

---
 modules/backup/default.nix     | 2 ++
 modules/monitoring/default.nix | 7 +++++++
 2 files changed, 9 insertions(+)

diff --git a/modules/backup/default.nix b/modules/backup/default.nix
index 0b45cac..8da51aa 100644
--- a/modules/backup/default.nix
+++ b/modules/backup/default.nix
@@ -46,6 +46,8 @@ let
         restic backup ${escapeShellArgs jobOptions.paths}
 
         restic check
+
+        echo "clerie_backup_last_successful_run_time{backup_job=\"${jobName}\", backup_target=\"${targetName}\"} $(date +%s)" > /var/lib/prometheus-node-exporter/textfiles/clerie-backup-${jobName}-${targetName}.prom
       '';
     }
   ) jobTargetPairs);
diff --git a/modules/monitoring/default.nix b/modules/monitoring/default.nix
index dcb541d..1e99857 100644
--- a/modules/monitoring/default.nix
+++ b/modules/monitoring/default.nix
@@ -66,8 +66,15 @@ in
       enabledCollectors = [
        "systemd"
       ];
+      extraFlags = [
+        "--collector.textfile.directory=/var/lib/prometheus-node-exporter/textfiles"
+      ];
     };
 
+    systemd.tmpfiles.rules = [
+      "d /var/lib/prometheus-node-exporter/textfiles - - - - -"
+    ];
+
     systemd.services."prometheus-node-exporter".serviceConfig.RestrictAddressFamilies = [ "AF_NETLINK" ];
 
     services.prometheus.exporters.bird = mkIf cfg.bird {