count-match-oid.pl · Mar 12, 23:26 by Shannon Wynter

You’re running Cacti and love it. But sadly you need to count the number of X connected to Y (In my case this happened to be users connected to an access concentrator)

SNMP and indeed Cacti doesn’t actualy have any built in method to do this already for you.

So I went and made one.

Step 1 -=- We need to make sure we have the perl librarys we need (You probably already do)
[root@localhost root]# perl -MCPAN -e 'install Net::SNMP'

*Step 2 -=-* Download or copy this script into a file under {cacti-dir}/scripts/

1. #!/usr/bin/perl  
2.  
3. use Net::SNMP;
4. use Getopt::Long;
5. use Data::Dumper;
6.  
7. use strict;
8.  
9. my ($help, $hostname, $snmp_community, $snmp_port, $snmp_timeout,
10. $snmp_version, $snmp_oid, $preg_match) =
11. (0,'127.0.0.1','public',161,10,1,'','');
12.  
13. Getopt::Long::Configure ('bundling');
14. GetOptions(
15. 'hostname|h=s' => \$hostname,
16. 'port|p=i' => \$snmp_port,
17. 'version|v=i' => \$snmp_version,
18. 'timeout|t=i' => \$snmp_timeout,
19. 'community|c=s' => \$snmp_community,
20. 'oid|o=s' => \$snmp_oid,
21. 'pregmatch|m=s' => \$preg_match,
22. 'help' => \$help
23. );
24.  
25. &Help if ($help || !($snmp_version eq '1') || ($snmp_oid eq '') || ($preg_match eq ''));
26.  
27. my ($session, $error) = Net::SNMP->session(
28. -hostname => $hostname,
29. -port => $snmp_port,
30. -timeout =>  $snmp_timeout,
31. -version => $snmp_version,
32. -community => $snmp_community
33. );
34.  
35. if (!defined($session)) {
36. printf("ERROR: %s.\n", $error);
37. exit 1;
38. }
39.  
40. my $result = $session->get_table(
41. -baseoid => $snmp_oid
42. );
43.  
44. if (!defined($result)) {
45. printf("ERROR: %s.\n", $session->error);
46. $session->close;
47. exit 1;
48. }
49.  
50. $session->close;
51.  
52. my $count = 0;
53. foreach my $key (keys(%$result)) {
54. if ($result->{$key} =~ /$preg_match/) {
55.   $count ++;
56. }
57. }
58.  
59. print $count;
60.  
61.  
62. sub Help {
63. print <<EOF;
64. count-match-oid.pl - Version 0.05
65. - Written by Shannon Wynter (http://fremnet.net/contact)
66. ----------------------------------------------------------------------------
67. Ever needed to count the number of snmp strings that match an expression?
68.  
69. Now you can
70. ----------------------------------------------------------------------------
71. Options (Those with * are required)
72.     -h--hostname  : The host to query  (default: 127.0.0.1)
73.     -p--port   : The port to query on  (default: 161)
74.     -v--version  : The SNMP version to use - Only supports 1 atm
75.     -t--timeout  : SNMP query timeout seconds(default: 10)
76.     -c--community  : SNMP query  (default: public)
77.     -o--oid  *: Base OID for searching in  (Numeric only)
78.     -m--pregmatch*: Perl regular expression to search for
79. --help   : This message
80. ---------------------------------------------------------------------------
81. Example
82.     count-match-oid.pl -h 172.16.0.2 -o ".1.3.6.1.2.1.2.2.1.2" -m "^<pppoe-"
83.  
84.     This will query the interace descriptions on host 172.16.0.2 and return
85.     the number that start with <pppoe-
86.  
87. EOF
88. exit 0;
89. }
90. Download this code: count-match-oid.pl (Downloaded 81 time(s))

Step 3 -=- Install the script into cacti

1. <cacti>  
2. <hash_030010de382638dacacdf9e7c60a3893dff150>
3.   <name>SNMP - Count Match OID</name>
4.   <type_id>1</type_id>
5.   <input_string>perl &amp;lt;path_cacti&amp;gt;/scripts/count-match-oid.pl -h &amp;lt;ip&amp;gt; -o "&amp;lt;oid&amp;gt;" -m "&amp;lt;match&amp;gt;"</input_string>
6.   <fields>
7.   <hash_070010ca07f2b6d7e6c094cc3e5f427d6d1dc5>
8.     <name>IP Address / Hostname</name>
9.     <update_rra></update_rra>
10.     <regexp_match></regexp_match>
11.     <allow_nulls></allow_nulls>
12.     <type_code>hostname</type_code>
13.     <input_output>in</input_output>
14.     <data_name>ip</data_name>
15.   </hash_070010ca07f2b6d7e6c094cc3e5f427d6d1dc5>
16.   <hash_070010584f637a9cf87562570eda9759b573a6>
17.     <name>Base OID (Numeric)</name>
18.     <update_rra></update_rra>
19.     <regexp_match></regexp_match>
20.     <allow_nulls></allow_nulls>
21.     <type_code></type_code>
22.     <input_output>in</input_output>
23.     <data_name>oid</data_name>
24.   </hash_070010584f637a9cf87562570eda9759b573a6>
25.   <hash_070010480838b7f2b1efda97713f94fb085822>
26.     <name>Perl Regecp For Matching</name>
27.     <update_rra></update_rra>
28.     <regexp_match></regexp_match>
29.     <allow_nulls></allow_nulls>
30.     <type_code></type_code>
31.     <input_output>in</input_output>
32.     <data_name>match</data_name>
33.   </hash_070010480838b7f2b1efda97713f94fb085822>
34.   <hash_0700105707de2afccf71666e1582bf1c216d83>
35.     <name>Number of matches</name>
36.     <update_rra>on</update_rra>
37.     <regexp_match></regexp_match>
38.     <allow_nulls></allow_nulls>
39.     <type_code></type_code>
40.     <input_output>out</input_output>
41.     <data_name>out_count</data_name>
42.   </hash_0700105707de2afccf71666e1582bf1c216d83>
43.   </fields>
44. </hash_030010de382638dacacdf9e7c60a3893dff150>
45. </cacti>
46. Download this code: cacti_count_oid.xml (Downloaded 82 time(s))

Log into Cacti, go to “Import Templates”
Browse to where you stored your download and select it
Click “Save”

This will create the Data Input Method – SNMP – Count Match OID

Step 4 -=- Create a Data Template
Go to “Data Templates” and click “Add”
Fill in the Data Template Name field…
example: Online - PPPoE Users
Fill in the Data Source Name field…
example: |host_description| - Online - PPPoE Users
Select SNMP – Count Match OID from the Data Source Input Method field.
Fill in the Internal Data Source Name field…
example: pppoe_count

Click Create

Cacti will save your input so far and reload the page with more fields for you…

Fill in the Base OID (Numeric) field…
example: .1.3.6.1.2.1.2.2.1.2
Fill in the Perl Regexp For Matching field…
example: ^<pppoe-

Click Save

Step 4 -=- Create a Graph Template
Well, I’ve taken you this far… The remainder is not so hard to work out…

I might come back later and complete these instructions if people complain (c:

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