From 36ac1fa6025c75b9eac404fee4cb33fccda9179a Mon Sep 17 00:00:00 2001
From: Emery Hemingway <ehmry@posteo.net>
Date: Sun, 23 Jan 2022 17:18:58 +0100
Subject: [PATCH] nncp: collect statistics

Publish the spool size and packet count for each neighbour.
---
 hosts/containers/nncp/collectd_nncp.nim | 41 +++++++++++++++++++++++++
 hosts/containers/nncp/default.nix       | 12 ++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 hosts/containers/nncp/collectd_nncp.nim

diff --git a/hosts/containers/nncp/collectd_nncp.nim b/hosts/containers/nncp/collectd_nncp.nim
new file mode 100644
index 00000000..76dfdc72
--- /dev/null
+++ b/hosts/containers/nncp/collectd_nncp.nim
@@ -0,0 +1,41 @@
+import std/[os, strutils]
+
+import posix
+
+proc getFileSize(path: string): BiggestInt =
+  var rawInfo: Stat
+  if stat(path, rawInfo) < 0'i32:
+    raiseOSError(osLastError(), path)
+  rawInfo.st_size
+
+let
+  hostname = getEnv("COLLECTD_HOSTNAME", "localhost")
+  interval = max(60, getEnv("COLLECTD_INTERVAL", "0").parseFloat.int)
+  args = commandLineParams()
+
+doAssert(args.len == 1, "pass only the NNCP spool directry as an argument")
+
+proc sumDir(path: string): tuple[size: BiggestInt, packets: int] =
+  for kind, path in walkDir path:
+    if kind == pcFile:
+      result.size = result.size + getFileSize(path)
+      inc result.packets
+
+while true:
+  for kind, path in walkDir args[0]:
+    if kind == pcLinkToDir:
+      var nodeName = extractFilename path
+      block:
+        var rx = sumDir(path / "rx")
+        stdout.writeLine("""PUTVAL "$#/nncp-$#/bytes-rx" interval=$# N:$#""" %
+          [hostname, nodeName, $interval, $rx.size])
+        stdout.writeLine("""PUTVAL "$#/nncp-$#/pending_operations-rx" interval=$# N:$#""" %
+          [hostname, nodeName, $interval, $rx.packets])
+      block:
+        var tx = sumDir(path / "tx")
+        stdout.writeLine("""PUTVAL "$#/nncp-$#/bytes-tx" interval=$# N:$#""" %
+          [hostname, nodeName, $interval, $tx.size])
+        stdout.writeLine("""PUTVAL "$#/nncp-$#/pending_operations-tx" interval=$# N:$#""" %
+          [hostname, nodeName, $interval, $tx.packets])
+  flushFile stdout
+  sleep interval*1000
diff --git a/hosts/containers/nncp/default.nix b/hosts/containers/nncp/default.nix
index 8b2be4cf..ae647874 100644
--- a/hosts/containers/nncp/default.nix
+++ b/hosts/containers/nncp/default.nix
@@ -4,6 +4,7 @@
   boot.loader.initScript.enable = lib.mkForce false;
 
   c3d2.mergeNncpSettings = false;
+  c3d2.hq.statistics.enable = true;
 
   networking = {
     hostName = "nncp";
@@ -23,6 +24,17 @@
     };
   };
 
+  services.collectd.plugins.exec = let
+    util =
+      pkgs.runCommand "collectd_nncp" { nativeBuildInputs = [ pkgs.nim ]; } ''
+        cp ${./collectd_nncp.nim} ./collectd_nncp.nim
+        nim c --nimcache:. -o:$out ./collectd_nncp.nim
+      '';
+  in ''
+    Exec "${config.services.collectd.user}" "${util}" "${config.programs.nncp.settings.spool}"
+  '';
+  users.groups.uucp.members = [ config.services.collectd.user ];
+
   services.nncp = {
     caller.enable = false;
     daemon = {