[hobbit] NKedit and Instructions

Fri Jul 21 11:24:27 CEST 2006

On Thu, Jul 20, 2006 at 07:09:26PM -0400, Epp, Matthew Contractor PEO EIS AKO wrote:
> The one feature I'm focusing on right now is similar to the "Instructions"
> section handled by NKedit. In my custom BB, I edited a section of
> dohostsvc.c to read in files containing plain text or html. This content
> gets placed at the bottom of any page generated from bb-dohostsvc.sh.
[snip]
> What I need to do now is decide how best to proceed with setting this up in
> Hobbit. I'd like to be able to edit the content from the web interface
> somehow. The "Instruction" field in the existing nkedit is good for short
> comments, but we've been using long descriptive html output with web links
> and such. With some experimentation, I found that you can do the same thing
> in nkedit, but you have to remove any special tags like nbsp; and all
> newline characters or it makes the hobbit-nkview.cfg file unreadable.
> 
> I'm going to start looking at the source for bb-hostsvc.sh tomorrow to see
> where I'd need to make changes, but I wanted to throw this out there to see
> if anyone had any thoughts. If anyone else would also like my existing code
> for BB, I can post that. :)

You're welcome to look at the source code, but this particular bit of
Hobbit is not one of the prettier in terms of how it's implemented :-)
Eventually you will end up in lib/htmllog.c and try to tweak that.

However, I think you could do this without changing a single line of
code in Hobbit. The ~hobbit/server/web/hostsvc_footer is already
inserted at the bottom of all the status pages (in the default setup,
it's just a link to bb_footer, but copy that and make your own file). 

You can implement your custom instructions by adding an HTML "object" to 
that file; you can get the hostname and columnname of the host being
viewed by using &BBHOST and &BBSVC placeholders. So you can use this 
as parameters to a CGI script that delivers your instructions for this
specific host+test combination, and by embedding it in an <object>
section, it will automatically be shown as part of the status page.

E.g. in the hostsvc_footer you add

    <center>
      <object 
           data="&CGIBINURL/instructions.sh?HOST=&BBHOST&SVC=&BBSVC"
           type="text/html" width="60%">
              No instructions
      </object>
    </center>

near the top of the hostsvc_footer filer.

Your "instructions.sh" script would need to grab the QUERY_STRING
environment variable which holds the HOST and SVC parameters, match
those against your configuration file, and output an HTML document 
with the instructions. A simple shell script would be something like
(note that writing GCI shell scripts are a bad idea, security-wise):

#!/bin/sh

set `echo "$QUERY_STRING" | sed -e 's!&! !g'`

while test "$1" != ""; do
    case "$1" in
      HOST=*)
         HOSTNAME=`echo $1 | cut -d= -f2`
	 ;;
      SVC=*)
         SERVICE=`echo $1 | cut -d= -f2`
	 ;;
    esac

    shift
done

echo "Content-type: text/html"
echo ""
echo "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 Transitional//EN\" \"http://www.w3.org/TR/html4/loose.dtd\">"
echo "<html><head><title>Instructions</title></head>"
echo "<body bgcolor=\"#ffffff\">"
echo "These are the instructions for host $HOSTNAME / service $SERVICE"
echo "</body></html>"
echo ""

exit 0

Similar things can be written in Perl, Python, C or whatever your
preferred language may be. Note that setting a <font> or BGCOLOR is
necessary; my first tests of this ended up with black-on-black which
is not easy to read :-)

One nice aspect of this is that you have completely de-coupled the
maintenance of the instructions from Hobbit. If you have a content
management system for uploading the instructions, you can use that to
maintain the data. Or any other tool which is appropriate.

Regards,
Henrik