From 21fcd4949e7ce10906e5c8a9b91bbd9151013afe Mon Sep 17 00:00:00 2001
From: Daniel Berteaud <daniel@firewall-services.com>
Date: Fri, 11 Oct 2019 11:41:05 +0200
Subject: [PATCH] Enhance ZFS monitoring scripts to retrieve ARC stats

---
 zabbix_conf/zfs.conf     |  4 ++++
 zabbix_scripts/check_zfs | 14 +++++++++++++-
 zabbix_scripts/disco_zfs |  8 ++++++--
 3 files changed, 23 insertions(+), 3 deletions(-)

diff --git a/zabbix_conf/zfs.conf b/zabbix_conf/zfs.conf
index 6e7074a..6f69d6e 100644
--- a/zabbix_conf/zfs.conf
+++ b/zabbix_conf/zfs.conf
@@ -13,3 +13,7 @@ UserParameter=vfs.zfs.dataset.info[*],/var/lib/zabbix/bin/check_zfs --dataset=$1
 # Type: Agent or Agent (active)
 # Sanoïd snapshot monitoring
 UserParameter=vfs.zfs.sanoid.check[*],/var/lib/zabbix/bin/check_zfs --sanoid=$1
+
+# Type: Agent or Agent (active)
+# ARC stats
+UserParameter=vfs.zfs.stats.all[*],/var/lib/zabbix/bin/check_zfs --stats=$1
diff --git a/zabbix_scripts/check_zfs b/zabbix_scripts/check_zfs
index d333ff8..9c47901 100644
--- a/zabbix_scripts/check_zfs
+++ b/zabbix_scripts/check_zfs
@@ -10,12 +10,14 @@ my $json       = {};
 my $pool       = undef;
 my $dataset    = undef;
 my $sanoidmon  = undef;
+my $stats      = undef;
 my $pretty     = 0;
 
 GetOptions(
   "zpool|pool=s" => \$pool,
   "dataset=s"    => \$dataset,
   "sanoid=s"     => \$sanoidmon,
+  "stats=s"      => \$stats,
   "pretty"       => \$pretty
 );
 
@@ -34,7 +36,7 @@ if (defined $sanoidmon and not grep { $_ eq $sanoidmon } qw(snapshot capacity he
   die 'ZBX_NOTSUPPOTED';
 }
 
-if (not $pool and not $dataset and not $sanoidmon){
+if (not $pool and not $dataset and not $sanoidmon and not $stats){
   print <<_EOF;
 Usage:
 $0 [--zpool=<name>|--dataset=<fs zvol or snap>|--sanoid=<snapshot|capacity|health>]
@@ -74,6 +76,16 @@ if ($pool){
 } elsif ($sanoidmon){
   print qx($sanoid --monitor-$sanoidmon);
   exit $?;
+} elsif ($stats){
+  if (not -e '/proc/spl/kstat/zfs/' . $stats){
+    print 'ZBX_NOTSUPPORTED';
+    exit 0;
+  }
+  open STATS, '</proc/spl/kstat/zfs/' . $stats;
+  while (<STATS>){
+    next unless (m/^(\w+)\s+4\s+(\d+)$/);
+    $json->{$1} = $2;
+  }
 }
 
 print to_json($json, { pretty => $pretty }) . "\n";
diff --git a/zabbix_scripts/disco_zfs b/zabbix_scripts/disco_zfs
index 231a711..f5bb56d 100644
--- a/zabbix_scripts/disco_zfs
+++ b/zabbix_scripts/disco_zfs
@@ -22,6 +22,7 @@ my $fs         = 0;
 my $zvol       = 0;
 my $snap       = 0;
 my $sanoidmon  = 0;
+my $arcstats   = 0;
 my $pretty     = 0;
 
 GetOptions(
@@ -30,13 +31,14 @@ GetOptions(
   "zvols|volumes"   => \$zvol,
   "snapshots"       => \$snap,
   "sanoid"          => \$sanoidmon,
+  "arcstats"        => \$arcstats,
   "pretty"          => \$pretty
 );
 
-if ($fs or $zvol or $snap or $sanoidmon){
+if ($fs or $zvol or $snap or $sanoidmon or $arcstats){
   $pools = 0;
 }
-if ($pools + $fs + $zvol + $snap + $sanoidmon != 1){
+if ($pools + $fs + $zvol + $snap + $sanoidmon + $arcstats != 1){
   die "One and only one type of discovery should be provided\n";
 }
 if ($sanoidmon and not $sanoid){
@@ -69,5 +71,7 @@ if ($pools){
   }
 } elsif ($sanoidmon){
   push @{$json->{data}}, { '{#ZFS_SANOID}' => $_ } foreach (qw(snapshot capacity health));
+} elsif ($arcstats){
+  push @{$json->{data}}, { '{#ZFS_STATS}' => 'arcstats' };
 }
 print to_json($json, { pretty => $pretty });