Internode quota from the Ubuntu command line

I have an Internode ADSL connection and I'm running Ubuntu Server (12.04). I wanted to be able to check my internet quota from the command line and i found a perl script to help do that, but there weren't quite enough instructions there for me to make it work. It wasn't too hard to fix though:

$ wget http://zwitterion.org/software/internode-quota-check/internode-quota-check
$ chmod +x internode-quota-check
$ mv internode-quota-check internode-quota-check.sh
$ sudo apt-get install libwww-mechanize-perl libreadonly-perl
$
$ ./internode-quota-check.sh man
you don't seem to have a ~/.fetchmailrc, so I'll prompt you.
To avoid extra dependencies, your password will be echoed.
Username: juliusroberts
Password: passwordhere
Run this command to create a ~/.fetchmailrc file:
echo '# poll mail.internode.on.net user "juliusroberts" password "passwordhere"' >> ~/.fetchmailrc
$ echo '# poll mail.internode.on.net user "juliusroberts" password "passwordhere"'>> ~/.fetchmailrc
$
$ ./internode-quota-check.sh
juliusroberts: 132.032 GB (88.0%) and 13.6 days (48.5%) left on 150 GB, 24 Mb/s plan.
$

So I then went and added  ./internode-quota-check.sh to the bottom of my ~/.bashrc file.  So now when i login to my server i see straight away how much internets i have left, yay :)

Use perl to check spamhaus status in Nagios

We had an issue where something on our internal network was tripping a SMTP spam filter at spamhaus.org.  We thought we fixed it once only to be bitten again a few months later and payslips from our payrol system were bouncing (bad).  As well as actually investigating the root cause, we created a nagios check to check spamhaus programatically.  Creating a custom nagios check is well documented on the nagios website.

#!/usr/bin/perl
#
# Quick perl script to check spamhaus to see if we're blocked again, see https://rt.wilderness.org.au:444/rt/Ticket/Display.html?id=73259
#
# This script returns values consistent with the nagios return code specification at http://nagiosplug.sourceforge.net/developer-guidelines.html#AEN76
# 0     OK          The plugin was able to check the service and it appeared to be functioning properly
# 1     Warning     The plugin was able to check the service, but it appeared to be above some "warning" threshold or did not appear to be working properly
# 2     Critical    The plugin detected that either the service was not running or it was above some "critical" threshold
# 3     Unknown     Invalid command line arguments were supplied to the plugin or low-level failures internal to the plugin 
#                       (such as unable to fork, or open a tcp socket) that prevent it from performing the specified operation. Higher-level errors 
#                       (such as name resolution errors, socket timeouts, etc) are outside of the control of plugins and should generally NOT be reported as UNKNOWN states.

use strict;
my $our_external_ip = "xxx.xxx.xxx.xxx"; 
my $exit_value=3;

# run the wget command and save it's output to the $results variable.
my $results=`/usr/bin/wget --random-wait -U mozilla -O /tmp/spamcheck.dat -o /tmp/spamcheck.log http://www.spamhaus.org/query/ip/$our_external_ip && grep $our_external_ip /tmp/spamcheck.dat`; 
chomp($results); 
#print $results."\n";

# check to see if we score RED ie; we're on a blocklist
if ($results =~ m/red/) {
    print "ALERT: Block found.  Check http://www.spamhaus.org/query/ip/$our_external_ip\n";
    $exit_value=2;
} 

# if we got this far, we saw no RED.  Check to see we at least get one GREEN.
elsif ($results =~ m/green/) {
    print "OK; We got a green and no red.\n";
    $exit_value=0; 
} 

# ALERT: We got no red AND no green; therefore there bust be some issue somewhere!
else {
    print "ALERT: No valid return codes detected; page-load/dns/internet/scripting issue?\n";
    $exit_value=3; 
}

#print "\nPerl hopes it's returning a \$exit_value of $exit_value\n\n";
exit $exit_value;

note that /tmp/spamcheck.* will need to be globally writable.

That then results in a nice web gui telling us all isn't well (again).  Happy with my work i told my boss who said "i don't like it, i want it to say OK", to which i replied, "i can do that ;)", and now you can too.  Happy automation :)

All your servers are belong to Ansible.

So say you've got a few *NIX servers of various flavors, a dozen or two; it takes a day or so to add a new one to production, installing ntp, configuring your custom software repositories, configuring the various accounts it might need, installing ssh, adding it to the backup system, to the monitoring system etc etc.  Say you're getting over it.  Say you need to change your software repositories or your admin ssh keys.  Familiar?  enter server automation:

(image borrowed from http://devopsanywhere.blogspot.com.au/)

We'd heard about chef, and tried puppet; the uuber configuration management system which is great, so they say; on the 3rd or 4th incarnation :)  We wanted something a bit simpler something that avoided the monolithic client/server model, could be run anywhere (with git) and which used the SSH key auth we were already using.  It had to be able to manage groups of machines in a logical "idempotent" way.  Idempotent means you can apply a play which says "make it like thus" and if nothing needs to change, nothing is changed.  You can apply it again (and again) and not break anything.

So anyhow we found all of that in a free open source software project called Ansible;

"Orchestrate From Above.
Most software does not run on a single machine.
Ansible parallelizes complex multi-tier rollouts across app servers, databases, monitoring servers, and load balancers.."

after following the doco I had it up and running managing NTP on 25 servers within a day.  A good percentage of that was spent sorting out root ssh access (although sudo is ok too) and finding out what NTP is actually packaged as on centos vs ubuntu vs debian etc.

We've now moved on to managing users and ssh keys with Ansible and i can see this making a very significant difference for us.