Shell Programming and Scripting

I'd like to automate some common DNS checks that I do regularly. I do tech support, part of my job being to walk customers through setting up various DNS records, including SPF and DKIM. Most of these customers are small to medium sized businesses. The first part of the call is always me doing some dig commands to see what the name servers are, what their current TXT records are. Then when we're done I check again this time checking their DKIM, two TXT records with two hosts.

So working manually, first I do a couple basic checks:

Code:

dig example.com NS
dig example.com TXT

Then again to check our work, I run through everything we've done.

Code:

dig example.com TXT

dig examplehost1.example.com TXT 
dig examplehost2.example.com TXT

dig examplehost3.example.com A
dig examplehost3.example.com MX
dig examplehost3.example.com TXT

I don't have any experience with Bash scripting but I think that a Bash script would be the right tool for this job. If it were just a list of commands run on the root domain, it'd be easier but there are host names and so on to insert in front of the domain.

Any ideas and code examples on how to automate this process would be greatly appreciated. By the way, my research into dig has already yielded and improvement. I added +noall +answer to a .digrc file meaning dig now only returns the answer not all the extraneous (to me) information.

Thank you.

Imagine that your script would:
prompt for the domain
execute a couple of dig commands
perhaps (in addition to display) have the computer check the results

So... what would you write to begin this task?

Thanks for the response!!
Here's what I have so far. I don't yet know the syntax so I'm just trying to write something that seems reasonable.

Code:

#!/bin/bash

echo Please, enter a domain name.
read DOMAIN

dig $DOMAIN NS
dig $DOMAIN TXT

dig k1._domainkey.$DOMAIN TXT
dig _domainkey.$DOMAIN TXT

---------- Post updated at 07:46 AM ---------- Previous update was at 07:38 AM ----------

Any suggestions on what I should do next? I realize I have to learn Bash script syntax but does the basic logic seem reasonable? I know it's a bit simplistic but I figure I should get something to work for my first script and then add features later...

---------- Post updated at 07:53 AM ---------- Previous update was at 07:46 AM ----------

Wow, actually, my script worked. I'm shocked. It's not fancy but it basically did what i wanted. I have to improve it for sure.

Probably next steps would be to experiment with what is returned from the dig commands.

For instance, save the return message to a variable.
Then, see if it contains or does not contain an important message.
Finally, based on the "if" statement you just did, you could display either
OK -- full return message here
*ERROR* - unknown ___ -- full return message here

Experiment a little with this.
I know when I was a Sys Admin (long ago), I had many scripts that would run and alert me when an error. In my case, the script would email me when something was wrong.

I get what you're saying now. Sorry for being dense. You're saying that I'd do an "if" statement to process the output, presumably after validating it in some way. It would either succeed or fail. Then I need to have the script tell me what is broken if there's a problem.

I like the idea of it doing some sort of validation and then emailing or otherwise notifying me if there's a problem. I'm not sure what a problem would be I guess an invalid spf record but I'm not yet sure how to check for that.

Your current example is rather simple where you are looking for the result.
I remember looking at sites and also doing repeated PING tests to the site to measure responsiveness. And rather than seeing results from ten PING's, I had a summary message to tell me - for instance "8/10 PING command response <__seconds"
Or, maybe you would do a WHOIS command to the domain, and grep for "STATUS" to make sure the domain is active.

Great ideas. I'll make this script less simplistic and post it again. Thank you!