[op5-users] User experience with Merlin first time install

[Andreas Ericsson]

Frater, Greg J wrote:
> Andreas et. al.,
> 
> Based on information from the Nordic Meet, it looks like Merlin and
> Ninja are going to be default Nagios components in the future, thus I
> thought I would offer 2 cents worth of documentation and testing of
> Merlin from a users perspective.
> 

Ooh, neat :-)

> Environment: Nagios 3.0.6 MySQL 5.0.45 OS: RHEL 5.3 64-bit Merlin:
> 0.5 Setup: Single Nagios installation with all components (Nagios
> core, CGI's, NagVis, PNP, Merlin, etc.) running on the same box,
> monitoring 577 hosts and 5290 services.
> 
> Download source:
> 

[ so far so good ]

> 
> Create mysql user for the merlin module to use when connecting to the
> database
> 
> mysql -u root -e \ CREATE USER merlin IDENTIFIED BY
> 'YourPasswordHere';
> 
> Compile Merlin:
> 
> make
> 
> I got some warnings when I ran make, I don't know what they mean.  I
> thought they might be related to my OS being 64 bit, but I don't
> know, I proceeded with my install  Here they are though Note: my
> install crashed 10 minutes after starting it up, this may be related,
> I posted the crash info seperately:
> 

They are related to 64-bitness of your system. It's safe to ignore them
until you're using more than 4 billion poller nodes to a single Merlin
system, so I haven't bothered to correct them.

> 
> Run Merlin Installation script:
> 
> sh install-merlin.sh --dest-dir=/usr/local/nagios/merlin
> --nagios-cfg=/usr/local/nagios/etc/nagios.cfg  --db-type=mysql
> --db-user=merlin --db-pass=YourPasswordHere --db-name=merlin
> 
> I got some errors on install: ERROR 1045 (28000): Access denied for
> user 'root'@'localhost' (using password: NO) ERROR 1045 (28000):
> Access denied for user 'root'@'localhost' (using password: NO) 
> Creating database merlin mysqladmin: connect to server at 'localhost'
> failed error: 'Access denied for user 'root'@'localhost' (using
> password: NO)'
> 
> ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using
> password: NO) Failed to setup database. Aborting.
> 
> The script expects your mysql database to allow the user
> root at localhost to login without a password.  We have a password for
> that user in our setup.  I messed with the install script a bit to
> get around it but don't know enough to know how to do this right.  So
> instead, I temporarily removed the password for this user on my
> system and reran the install script.  It worked after that.
> 

Right. I'll make it prompt the user for the password to use.

> The Merlin install script modifies your Nagios configuration files
> (specifically the main one nagios.cfg).  You need to check the Nagios
> config before restarting Nagios:
> 
> /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg
> 
> If the config verifies okay then restart Nagios: service nagios
> restart
> 
> Running configuration check...done. Stopping nagios: .done. Starting
> nagios:Logging to '/usr/local/nagios/merlin/logs/neb.log' 
> [1245098202] 6: Merlin Module Loaded [1245098202] 6: Coredumps in
> /tmp done.
> 
> It appeared to restart okay, though the last line 'Coredumps in /tmp'
> made me a bit nervous.
> 

Heh. It's only there to say "current working directory is ... ", but
when I added that line I was specifically looking for where Nagios put
its coredumps, so it turned out that way ;-)

> Start Merlin Daemon: service merlind start
> 
> I think that's it, it should be up and running.  The Merlin module
> logs events to /usr/local/nagios/merlin/logs/neb.log, and the daemon
> logs events to /usr/local/nagios/merlin/logs/daemon.log.
> 
> Andreas, please review these steps for accuracy, I'm working only
> from the README and guessing the rest.  Hopefully this is usefull to
> others.
> 

That's indeed the correct steps. I'll amend the install script so that
root users with a password for mysql can use it with less hassle than
temporarily removing the password though.

Thanks for the writeup! :-)

-- 
Andreas Ericsson                   andreas.ericsson at op5.se
OP5 AB                             www.op5.se
Tel: +46 8-230225                  Fax: +46 8-230231

Considering the successes of the wars on alcohol, poverty, drugs and
terror, I think we should give some serious thought to declaring war
on peace.