Setting up DomainKeys on Centos

This is a quick walk through on how to set up domain keys on Centos 5 using sendmail. It should also be very similar for Redhat or Fedora.

Domainkeys is a method mostly used by yahoo to verify that the sender of an email is valid. I did notice that gmail changes the domainkeys header line [...]

Setup a transparent proxy with 3 easy steps

First, Squid server installed (use up2date squid) and configured by adding following directives to file:
# vi /etc/squid/squid.conf

Optimizing Sendmail

Most of them involve changing the daemon’s configuration in /etc/sendmail.mc and rebuilding sendmail.cf
Specific things that can affect performance:
dnl # Sendmail, Chap 24.9.13, Page 955
dnl # Disable re-write of queue control file (will result in duplicates
dnl #   if the daemon is interrupted during a delivery)
define(`confCHECKPOINTINTERVAL’,`0′)dnl

HTPasswd Tutorial

If you would like to have a set of web pages that are protected, requiring a username/password to gain access, this tutorial will show you how to set it up. This is geared towards the Unix Apache httpd servers used on holly, lamar, and www.colostate.edu. If you are using another web server, you’ll need to [...]

Simple Web/Linux IP Address Lookup

If you’re going to be doing a lot of Geotargeting or IP Address Lookups, please take a feed instead which will preserve both our bandwidth and your bandwidth.
Simple GET
That said, there is an easy HTTP oriented API to locate IP addresses and Geocode them. If you don’t supply the “?ip=aa.bb.cc.dd” bit, [...]

How to manually install DKIM-Filter with Sendmail

Source: [click here]

Max 30 mins work.

However, life is rarely so simple.
yum search dkim didn’t find anything.

So, based on what I could find, I ended up here. Downloaded dkim-filter
2.4.1 and went on an epic voyage of discovery into the RFCs and other stuff.
I just want to install, configure and run the thing!

How to tune Apache and Mysql

By default, Apache comes preconfigured to serve a maximum of 256 clients simultaneously. This particular configuration setting can be found in the file /etc/httpd/conf/httpd.conf
If your server has 2 GB of RAM, and you’re sharing your server with MySQL(true in my case), you’ll want to reserve about half of it for Apache (1 GB)

Necessary commands (tips) to tune apache

To search in the current directory and all sub directories for a file named httpd.conf
find . -name “httpd.conf” -print
To find some string or text, type
find . -exec grep “MaxClients” ‘{}’ \; -print

How To Create SVN Repository

How to get help with svn?
If you are looking for svn reference in man pages, you have gone to the wrong place. To check the references of svn commands, simple do this:
svn help

How to configure YUM/WGET to get through using PROXY ?

Better answer – use /etc/profile.d/proxy.[csh,sh]

You just need to create the following files in /etc/profile.d, and then this will work in *any* shell for *any* user of the system:
#proxy.sh
export http_proxy=http://host.com:port/
export ftp_proxy=http://host.com:port/
export no_proxy=.domain.com
export HTTP_PROXY=http://host.com:port/
export FTP_PROXY=http://host.com:port/
#proxy.csh
setenv http_proxy http://host.com:port/
setenv ftp_proxy http://host.com:port/
setenv no_proxy .domain.com
setenv HTTP_PROXY http://host.com:port/
setenv FTP_PROXY http://host.com:port/

After that, you can run YUM/WGET