[ale] Bash Scripts for System Automation and Monitoring

[jimbutler1234567890 at gmail.com (Jim Butler)]

Hi..
I have many years of experience with Linux, but I'm finding out lately 
that apparently there is a good deal of mainstream knowledge that I've 
missed somewhere. Most Linux System Admin positions require that you 
know how to script so you can automate processes, and set up monitoring, 
etc..
Usually when I wanted to monitor a system, I set up Nagios for host 
monitoring, and then if I found a problem, I logged in manually to the 
host in questionn and used tools like top, vmstat, iftop, iostat, etc. 
for finding the cause of bottlenecks. But apparently when working on 
large deployments like where you have large clusters or other types of 
large setups, there need to be tools and/or scripts in place for 
monitoring. I need to learn this stuff! I'm teaching myself BASH 
scripting now, and so I have that under way. Also I know about using 
MRTG and CACTI and the like, for monitoring network traffic on switches. 
So let me ask everything this:
What "monitoring tools" or "automation tools" should a guy like me be 
learning to use, in order to be a good and marketable System 
Administrator? Where would you send a guy like me to learn the pieces he 
is missing? If you were in my shoes, what would you do to get up to 
speed most quickly? I'm looking for wisdom and guidance from Linux 
System Admins who are, well, better than me and more experienced than me.

Thank you in advance,
Jim Butler