Posts Tagged ‘lib’

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Fix to Nagios is currently not checking for external commands

Wednesday, August 24th, 2011

While I was deploying a new Nagios install to Monitor some Windows hosts I’ve came across the following error in Nagios’s web interface:

Sorry, but Nagios is currently not checking for external commands, so your command will not be committed!
Read the documentation for information on how to enable external commands...

This error is caused by an option configuration for /etc/nagios/nrpe.cfg (part of the nrpe-nagios-server Debian package.

The config variable in nrpe.cfg causing the error is check_external_command=0 , the fix comes to changing the variable to:

check_external_command=1

As well as restart the /etc/init.d/nagios-nrpe-server and /etc/init.d/nagios3 services:

debian:~# /etc/init.d/nagios3 restart
...
debian:~# /etc/init.d/nagios-nrpe-server
...

This changes has work out the error Sorry, but Nagios is currently not checking for external commands, so your command will not be committed! , however immediately after another kind of error appared in Nagios web interface when I tried to use the send Nagios commands button. The error was:

Error: Could not stat() command file '/var/lib/nagios3/rw/nagios.cmd'!

This error is due to a deb package, which seems to be affecting the current deb versions of Nagios shipped with Debian 6 Squeeze stable, as well as the Latest Ubuntu release 11.04.

Thanksfully there is a work around to the problem I found online, to fix it up I had to execute the commands:

debian:~# /etc/init.d/nagios3 stop debian:~# dpkg-statoverride --update --add nagios www-data 2710 /var/lib/nagios3/rw
debian:~# dpkg-statoverride --update --add nagios nagios 751 /var/lib/nagios3
debian:~# /etc/init.d/nagios3 start

And hooray Thanks God the error is gone 😉

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Posted in Linux, System Administration | 8 Comments »

How to generate user password for digest_pw_auth SQUID digest authentication

Wednesday, July 6th, 2011

Squid Proxy pass prompt / real squid fun picture

I needed to generate new password for proxy user configured on SQUID proxy server configured with digest user authentication.
My dear colleague was kind to provide me with the below script, which generates the one line string which needs to go to the squid user password file:

#!/bin/sh
user="$1";
realm="$2";
pass="$3";
if [ -z "$1" -o -z "$2" -o -z "$3" ] ; then
echo "Usage: $0 user password 'realm'";
exit 1
fi
ha1=$(echo -n "$user:$realm:$pass"|md5sum |cut -f1 -d' ')
echo "$user:$realm:$ha1"

You can alternatively download the squid_generate_pass.sh script here

The script accepts three arguments;
proxy-server:~# ./squid_generate_pass.sh
Usage: ./squid_generate_pass.sh user password 'realm'

Thus to generate a new user and password and insert it immediately into let’s say a squid configured user/pass file in /etc/squid3/users execute command:

proxy-server:~# ./squid_generate_pass.sh admin_user MySecretPassword 'Squid_Configured_Realm'
>> /etc/squid3/users

Where Squid_Configured_Realm depends on the realm name configured in squid.conf, for example if squid.conf includes some auth configuration similar to:

auth_param digest program /usr/lib/squid3/digest_pw_auth -c /etc/squid3/users
auth_param digest children 2
auth_param digest realm My_Proxy_Realm
acl localusers proxy_auth REQUIRED

The realm script argument should be My_Proxy_realm . If squid_generate_pass does completes without errors, it should add a line to /etc/squid3/users file similar to:

proxy-server:~# cat /etc/squid3/users
admin_user:My_Proxy_realm:3bbcb35e505c52a0024ef2e3ab1910b0

Cheers 😉

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Posted in Linux, System Administration | 1 Comment »

How to fix wicd 1.7.0+ds1-5 Connection Failed: Bad Password on Ubuntu 10.10 (Maverick Merkaaat)

Tuesday, May 3rd, 2011

I’ve been struggling with fixing a nasty error with wicd network manager for about 2 hours.
The exact error message I faced was:

Connection Failed: Bad Password

The issue occured after some suggested updates from the Ubuntu graphical update tool.
The wireless network to which it was connected was a WPA-PSK (WPA2) Passphrase authentication.
The network key was properly typed in and was working well on another system so the error Connection Failed: Bad Password made no sense.

There was nothing unusual in /var/log/wicd/wicd.log , that made me even more curious about what might be causing the error.After a lot of try outs and a lot of readings and tests I finally got the cause of the weird Bad Password errors produced by wicd

Weirdly enought, somehow the Ubuntu package update tool has installed the default gnome network-manager package.
The installed network-manager package has mismatched somehow the way wicd connects to wireless networks and as a cause the wpa_supplicant binary was not properly invoked.

As a consequence of the network-manager being present on the system the wpa_supplicant process which made the exact connection to the wireless network was not launching in, the exact wpa_supplicant invocation missing was:

wpa_supplicant -B -i wlan0 -c /var/lib/wicd/configurations/0022b0aa424a -D wext

Luckily the solution to the notebook wireless device unable to connect to the Wireless network was simple.

All I had to do is completely remove all occurance of network-manager packages installed on the Ubuntu system, by issuing the commands:

ubuntu:~# apt-get remove --yes network-manager
ubuntu:~# dpkg --purge network-manager-pptp-gnome network-manager-pptp network-manager

The reason for issuing the a dpkg –purge command was my desire to completely get rid of all kind of network-manager related configurations.

Now after re-connecting with wicd wireless manager, it worked fine 😉

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Posted in Linux, Linux and FreeBSD Desktop | 17 Comments »

How to solve “eAccelerator requires Zend Engine API version 220060519 , the Zend Engine API version 220090626 which is installed, is newer. Contact eAccelerator at http://eaccelerator.net for a later version of eAccelerator.” on FreeBSD

Monday, April 4th, 2011

I’ve recently upgraded my FreeBSD Apache server from port www/apache20 I had some issues before I tune up and recompile also the php5 port but eventually it worked out, however the Eaccelerator content caching module failed to load as it was outdated.

That’s a common inconvenient with eaccelerator that every system administrator out there has faced once or twice, especially on systems that has custom compiled Apache servers and does not use a specific precompiled version of the eaccelerator.

To solve the situation as you can expect I jumped on in the /usr/ports/www/eaccelerator and removed the current installed version of eaccelerator in order to compile and install the latest port version.:
To do that I first attempted to upgrade the eaccelerator port with portmaster but as there were some problems caused by autoconf initialization etc., I finally decided to abandon the idea of using portmaster and did it manually with the good old well known trivial commands:

freebsd# cd /usr/ports/www/eaccelerator
freebsd# make deinstall
freebsd# make install && make clean

I’ve continued further and restarted my Apache server to load the new eaccelerator version and made a small phpinfo php script to test if the eaccelerator is properly loaded, yet with zero success.

After checking out in my /var/log/httpd-error.log , I’ve determined the following error:

Failed loading /usr/local/lib/php/20060613/eaccelerator.so: Cannot open "/usr/local/lib/php/20060613/eaccelerator.so"

The error is quite obvious, to solve it I’ve opened my php configuration file /usr/local/etc/php.ini and placed in it:

and substituted the line:

zend_extension="/usr/local/lib/php/20060613/eaccelerator.so:"

with:

zend_extension="/usr/local/lib/php/20090626/eaccelerator.so"

Further on I gave Apache another restart with:

freebsd# /usr/local/etc/rc.d/apache2 restart
Performing sanity check on apache2 configuration:
Syntax OK
Stopping apache2.
Waiting for PIDS: 71140.
Performing sanity check on apache2 configuration:
Syntax OK
Starting apache2.

followed by another test if the eaccelerator is loaded with the phpinfo(); script.

Now even though the Failed loading /usr/local/lib/php/20060613/eaccelerator.so: Cannot open “/usr/local/lib/php/20060613/eaccelerator.so” was no more, the Eaccelerator was yet not loaded.

Another consult with /var/log/httpd-error.log now revealed me another eaccelerator error you read below:

eAccelerator requires Zend Engine API version 220060519.
The Zend Engine API version 220090626 which is installed, is newer.
Contact eAccelerator at http://eaccelerator.net for a later version of eAccelerator.

I did about 20 minutes of investigation on the internet looking for a possible fix which gave me some idea what might be the cause for error message, though it was finally my try/fail methodology that helped me solve the issue.

The solution to the issue appeared to be easy thanks God, to solve the error all you need to do is one more make clean right before installing the eaccelerator port.:
Here are the commands necessary to issue to solve the error and make the eaccelerator load properly:

freebsd# cd /usr/ports/www/eaccelerator
freebsd# make clean &&
freebsd# make install clean

Now after restarting the Apache server once again eaccelerator has properly been loaded once again.

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Posted in FreeBSD, System Administration | 2 Comments »

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