Differences

This shows you the differences between two versions of the page.

--- email_alerts_on_low_free_space [2009/08/18 10:24] – tkbletsc
+++ email_alerts_on_low_free_space [2017/05/28 15:34] (current) – tkbletsc
@@ Line 1: / Line 1: @@
 ====== Email alerts on low free space ======
-Create ''/root/free-space-alerts.pl'':
+Create ''/root/free-space-alerts.py'':
-<code=perl>
+<code=python>
-#!/usr/bin/perl
+#!/usr/bin/python
+import sys,os,socket,subprocess
-# Based on:
+def get_free_GB(path):
-#   http://www.cyberciti.biz/tips/howto-write-perl-script-to-monitor-disk-space.html
+	st = os.statvfs(dir)
+	avail = st.f_bavail * st.f_bsize / (1024.0**3) # free space in GB
+	total = st.f_blocks * st.f_bsize / (1024.0**3) # free space in GB
+	used = total - avail
+	return (avail,used,total)
-use strict;
+def send_email(to,subject,message):
-use warnings;
+ 	fp_mail = subprocess.Popen(['/usr/bin/mail',to,'-s',subject], stdin=subprocess.PIPE).stdin
-use Filesys::DiskSpace;
+	fp_mail.write(message)
+	fp_mail.close()
-if (@ARGV != 3) {
-        die "Syntax: $0 <email_address> <path> <min_space_GB>\n";
-}
-my ($to,$dir,$warning_level) = @ARGV;
+if len(sys.argv) != 4:
+	print "Syntax: %s <email_address> <path> <min_space_GB>" % sys.argv[0]
+	sys.exit(1)
+(_,to,dir,min_space_GB) = sys.argv
+min_space_GB = float(min_space_GB)
-my $hostname = `hostname` || 'localhost';
+hostname = socket.gethostname()
-chomp $hostname;
-# email setup
+(avail,used,total) = get_free_GB(dir)
-my $subject = "$hostname: Low disk space on $dir";
-# get df
+pct = avail/total*100
-my ($fs_type, $fs_desc, $used, $avail, $fused, $favail) = df $dir;
-$used /= 1024*1024; # to GB
+if avail < min_space_GB:
-$avail /= 1024*1024; # to GB
+	subject = "%s: Low disk space on %s" % (hostname, dir)
-my $total = $used + $avail;
+	message = """WARNING from '%s'.
-my $pct = $avail/$total*100;
-# compare
+Low disk space on $dir: %.1fGB / %.1fGB free (%.1f%%).  Threshold is %.1fGB.
-if ($avail < $warning_level) {
+""" % (hostname, avail, total, pct, min_space_GB)
-        open MAIL, "| /usr/bin/mail $to -s '$subject'" or die "mail: $!\n";
+	send_email(to,subject,message)
-        printf MAIL "WARNING from '$hostname'.\n\nLow disk space on $dir: %.1fGB / %.1fGB free (%.1f%%)\n",$avail,$total,$pct;
-        close MAIL;
-}
 </code>
 Then create ''/etc/cron.hourly/free-space-alerts'' with one line per mountpoint to monitor:
 <file>
-/root/free-space-alerts.pl <YOUR_EMAIL_ADDRESS> <DIRECTORY> <MINIMUM_SPACE_IN_GIGABYTES>
+/root/free-space-alerts.py <YOUR_EMAIL_ADDRESS> <DIRECTORY> <MINIMUM_SPACE_IN_GIGABYTES>
 ...
 </file>
-===== Alternate version that doesn't use Filesys::DiskSpace =====
-If you don't have that module, use this:
-<code=perl>
-#!/usr/bin/perl
-# Based on:
-#   http://www.cyberciti.biz/tips/howto-write-perl-script-to-monitor-disk-space.html
-use strict;
-use warnings;
-#use Filesys::DiskSpace;
-if (@ARGV != 3) {
-    die "Syntax: $0 <email_address> <path> <min_space_GB>\n";
-}
-my ($to,$dir,$warning_level) = @ARGV;
-my $hostname = `hostname` || 'localhost';
-chomp $hostname;
-# email setup
-my $subject = "$hostname: Low disk space on $dir";
-# get df
-my ($fs_type, $fs_desc, $used, $avail, $fused, $favail) = my_df($dir);
-$used /= 1024*1024; # to GB
-$avail /= 1024*1024; # to GB
-my $total = $used + $avail;
-my $pct = $avail/$total*100;
-# compare
-if ($avail < $warning_level) {
-    open MAIL, "| mail $to -s '$subject'" or die "mail: $!\n";
-    printf MAIL "WARNING from '$hostname'.\n\nLow disk space on $dir: %.1fGB / %.1fGB free (%.1f%%)\n",$avail,$total,$pct;
-    close MAIL;
-}
-sub my_df {
-        my ($p) = @_;
-        #Filesystem         1024-blocks      Used Available Capacity Mounted on
-        open DF, "df -P $p |" or die "df: $!\n";
-        scalar <DF>; # eat header
-        my $line = <DF>;
-        close DF;
-        my ($dev,$total,$used,$avail,$pct,$mountpoint) = split(/\s+/,$line);
-        return (0, '', $used, $avail, 0, 0); # (mostly) compatible with Filesys::DiskSpace
-}
-</code>