From 787e85373dadce37f265178dec445fb43fe35647 Mon Sep 17 00:00:00 2001
From: Florian Sesser <florian@private.storage>
Date: Wed, 10 Nov 2021 13:36:15 +0000
Subject: [PATCH] Monitoring: Add regular scraping for Tahoe OpenMetrics
statistics
---
morph/lib/storage.nix | 4 ++
nixos/modules/monitoring/exporters/tahoe.nix | 59 ++++++++++++++++++++
2 files changed, 63 insertions(+)
create mode 100644 nixos/modules/monitoring/exporters/tahoe.nix
diff --git a/morph/lib/storage.nix b/morph/lib/storage.nix
index 86e14228..15e23737 100644
--- a/morph/lib/storage.nix
+++ b/morph/lib/storage.nix
@@ -43,8 +43,12 @@ in {
../../nixos/modules/monitoring/vpn/client.nix
# Expose base system metrics over the monitoringvpn.
../../nixos/modules/monitoring/exporters/node.nix
+ # Collect Tahoe OpenMetrics statistics.
+ ../../nixos/modules/monitoring/exporters/tahoe.nix
];
+ services.private-storage.monitoring.tahoe.enable = true;
+
# Turn on the Private Storage (Tahoe-LAFS) service.
services.private-storage = {
# Yep. Turn it on.
diff --git a/nixos/modules/monitoring/exporters/tahoe.nix b/nixos/modules/monitoring/exporters/tahoe.nix
new file mode 100644
index 00000000..f63c21e3
--- /dev/null
+++ b/nixos/modules/monitoring/exporters/tahoe.nix
@@ -0,0 +1,59 @@
+# Tahoe Prometheus metrics collector
+#
+# Scope: Retrieves OpenMetrics from Tahoe and puts them
+# where textfile collector can find them.
+#
+# Usage: Import this to every server running Tahoe.
+#
+# See https://nixos.org/manual/nixos/stable/#module-services-prometheus-exporters
+
+{ config, options, lib, ourpkgs, pkgs, ... }:
+
+let
+ cfg = config.services.private-storage.monitoring.tahoe;
+
+in {
+ options.services.private-storage.monitoring.tahoe = {
+ enable = lib.mkEnableOption "Tahoe OpenMetrics collecting service";
+ scrapeEndpoint = lib.mkOption {
+ type = lib.types.str;
+ description = "Where to get our metrics from?";
+ default = "http://localhost:3456/statistics?t=openmetrics";
+ };
+ outFile = lib.mkOption {
+ type = lib.types.str;
+ description = "Where to store the temporary file for node exporter to scrape?";
+ default = "/run/prometheus-node-exporter/tahoe.prom";
+ };
+ interval = lib.mkOption {
+ type = lib.types.str;
+ description = ''
+ How often to do it?
+ See https://www.freedesktop.org/software/systemd/man/systemd.time.html#Calendar%20Events
+ '';
+ # Every five minutes.
+ default = "*:0/5";
+ };
+ };
+
+ config =
+ lib.mkIf cfg.enable {
+ environment.systemPackages = [ pkgs.curl ];
+ systemd.services.tahoe-metrics-collector = {
+ enable = true;
+ description = "Tahoe metrics gathering service";
+ wantedBy = [ "multi-user.target" ];
+ startAt = cfg.interval;
+ path = [ pkgs.curl ];
+
+ # Curl to a temp file and then move atomically so textfile collector
+ # won't read a partial file.
+ # See https://github.com/prometheus/node_exporter#textfile-collector
+ script = ''
+ curl --silent --show-error --fail-with-body --output "${cfg.outFile}.tmp" "${cfg.scrapeEndpoint}"
+ mv "${cfg.outFile}.tmp" "${cfg.outFile}"
+ '';
+ };
+ };
+}
+
--
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