Basics

Here’s how to install Ruby on Rails on a cPanel system:

Update: These instructions were modified for Ruby 1.8.6, since 1.8.5 is no longer available!

First install Ruby:

wget ftp://ftp.ruby-lang.org/pub/ruby/1.8/ruby-1.8.6.tar.gz
tar -xvzf ruby-1.8.6.tar.gz
cd ruby-1.8.6
./configure
make
make install

Now, install the Gems and Rails:

wget http://rubyforge.org/frs/download.php/11289/rubygems-0.9.0.tgz
tar -xvzf rubygems-0.9.0.tgz
cd rubygems-0.9.0
ruby setup.rb
gem install rails

Install Fast CGI

wget fastcgi.com/dist/fcgi-2.4.0.tar.gz
tar -xvzf fcgi-2.4.0.tar.gz
cd fcgi-2.4.0
./configure
make
make install

wget fastcgi.com/dist/mod_fastcgi-2.4.2.tar.gz
tar -xvzf mod_fastcgi-2.4.2.tar.gz
cd mod_fastcgi-2.4.2
/usr/local/apache/bin/apxs -o mod_fastcgi.so -c *.c
/usr/local/apache/bin/apxs -i -a -n fastcgi mod_fastcgi.so
gem install fcgi

Edit the Apache config file and add the fcgi module:

pico /usr/local/apache/conf/httpd.conf

LoadModule fastcgi_module libexec/mod_fastcgi.so
FastCgiIpcDir /tmp/fcgi_ipc/
AddHandler fastcgi-script .fcgi
< /IfModule>

Then restart Apache

Install RMagick and GetText:

wget http://umn.dl.sourceforge.net/sourceforge/graphicsmagick/GraphicsMagick-1.1.7.tar.gz
tar -xvzf GraphicsMagick-1.1.7.tar.gz
cd GraphicsMagick-1.1.7
./configure
make
make install

Install MySQL for Ruby:

gem install mysql

Now make the test Installation. To do this, log in as your user (not root)

su user
cd ~
rails test
cd public_html
ln -s ../test/public/ rails
cd ../test/
chmod -Rf 777 tmp/
cd public
chmod 755 dispatch.fcgi
pico .htaccess

Now, find the line in the .htaccess that looks something like this:

RewriteRule ^(.*)$ dispatch.cgi [QSA,L]

And change “dispatch.cgi” to “dispatch.fcgi”

To see if you’ve installed everything properly, just browse to the Rails folder:

http://yourdomain.com/rails/

I know you’ve provably seen a lot of guides on how to install ffMPEG, but I’ve noticed that most of them are incomplete and don’t cover the possible issues that can arise during installation. I’ve installed ffMPEG on dozens of servers and have devised a standardized procedure on what I feel is the best way to perform this installation.

This walkthrough has been tested on systems running Redhat 9, RHEL 4, and CentOS 4.5 and it may also work on other distributions and versions. Our servers also run cPanel 11, but this is in no way required in order to install ffMPEG. I assume at this point that you have root access and that yum (or another similar package manager) is installed.

ffMPEG commonly consists of and includes the following software:

– Essential / MPlayer
– FLVtool2 (Requires a Ruby Core)
– LAME MP3 Encoder
– php-ffMPEG
– ffMPEG
– libOgg
– libvorbis

To start out, enter into a temporary source directory and download all the binaries:

cd /usr/src
wget http://www3.mplayerhq.hu/MPlayer/releases/codecs/essential-20061022.tar.bz2
wget http://www4.mplayerhq.hu/MPlayer/releases/MPlayer-1.0rc2.tar.bz2
wget http://rubyforge.org/frs/download.php/17497/flvtool2-1.0.6.tgz
wget http://easynews.dl.sourceforge.net/sourceforge/lame/lame-3.97.tar.gz
wget http://superb-west.dl.sourceforge.net/sourceforge/ffmpeg-php/ffmpeg-php-0.5.0.tbz2

*These are the latest stable versions at the time this article was written. If you are unable to download any of the above, you’ll need to visit the distributor’s site and download the latest stable version available.

Now extract everything:

bunzip2 essential-20061022.tar.bz2; tar xvf essential-20061022.tar
tar zxvf flvtool2-1.0.6.tgz
tar zxvf lame-3.97.tar.gz
bunzip2 ffmpeg-php-0.5.0.tbz2; tar xvf ffmpeg-php-0.5.0.tar
bunzip2 MPlayer-1.0rc2.tar.bz2 ; tar -xvf MPlayer-1.0rc2.tar

Create and import the Codecs directory:

mkdir /usr/local/lib/codecs/
mv essential-20061022/* /usr/local/lib/codecs/
chmod -Rf 755 /usr/local/lib/codecs/

Install Subversion and Ruby

yum install subversion
yum install ruby  (If you’re on cPanel you can alternatively use /scripts/installruby)
yum install ncurses-devel

Get ffMPEG and MPlayer from SVN:

svn checkout svn://svn.mplayerhq.hu/ffmpeg/trunk ffmpeg
svn checkout svn://svn.mplayerhq.hu/mplayer/trunk mplayer

Install LAME:

cd /usr/src/lame-3.97
./configure && make && make install

Install libOgg and libVorbis:

yum install libogg.i386
yum install libvorbis.i386
yum install libvorbis-devel.i386

Install flvtool2

cd /usr/src/flvtool2-1.0.6/
ruby setup.rb config
ruby setup.rb setup
ruby setup.rb install

Install MPlayer:

cd /usr/src/MPlayer-1.0rc2

Install ffMPEG:

cd /usr/src/ffmpeg/ ./configure –enable-libmp3lame –enable-libvorbis –disable-mmx –enable-shared make && make install

This is the typical configure line that I use, but you can customize this to what you need. For available configure options, type ./configure –help. Your custom configuration may require the installation of additional software on the server.

ln -s /usr/local/lib/libavformat.so.50 /usr/lib/libavformat.so.50 ln -s /usr/local/lib/libavcodec.so.51 /usr/lib/libavcodec.so.51 ln -s /usr/local/lib/libavutil.so.49 /usr/lib/libavutil.so.49 ln -s /usr/local/lib/libmp3lame.so.0 /usr/lib/libmp3lame.so.0 ln -s /usr/local/lib/libavformat.so.51 /usr/lib/libavformat.so.51

You may get an error about a library path not being found, if so, run

export LD_LIBRARY_PATH=/usr/local/lib

If this is being installed on a dedicated server, you might also get an error about the /tmp directory not be executable, which is common when installing on a dedicated server with a separate /tmp partition mounted noexec. In this case, you will need to create a tmp dir in the ffmpeg folder and use that as the tmp disk for now:

mkdir tmp chmod 777 tmp export TMPDIR=./tmp

Then run the configure command and set the TMPDIR variable back.

export TMPDIR=/tmp

Install ffMPEG-php

cd /usr/src/ffmpeg-php-0.5.0/ phpize ./configure && make && make install ln -s /usr/local/bin/ffmpeg /usr/bin/ffmpeg ln -s /usr/local/bin/mplayer /usr/bin/mplayer

When the installation is complete, it will give you a long path to the shared libraries. This needs to be copied to the php.ini as so:

[ffmpeg] extension=/usr/local/lib/php/extensions/no-debug-non-zts-20020429/ffmpeg.so

or in most cases where the extension_dir variable is set, just do:

extension=”/ffmpeg.so”

The ‘no-debug-non-zts-xxxxxxxx’ directory will be the one provided during installation. When this is done, restart Apache and check that the module is loaded in PHP:

/etc/init.d/httpd restart php -r ‘phpinfo();’ | grep ffmpeg

Look for this:

ffmpeg
fmpeg support (ffmpeg-php) => enabled
ffmpeg-php version => 0.5.0
ffmpeg.allow_persistent => 0 => 0

If you only get output for the ‘PWD’ variables, make sure that the extension_dir path is correct in the phpinfo file. Sometimes there are two specified, and if that is the case then the incorrect one should be commented out.

Test out ffmpeg for errors just by typing ffmpeg at the command line. The most common error is:

ffmpeg: error while loading shared libraries: libavformat.so.51: cannot open…

To correct this, edit /etc/ld.so.conf and add the line

/usr/local/lib

then save and exit.

Now run this command to reload the library cache:

ldconfig -v

You’re all done…enjoy!

./configure && make && make install

Have you ever received a bounce for spam that was sent by you…only it wasn’t sent by you? Email spoofing is one of the easiest concepts to understand for us, but the hardest to explain to end users who confuse spoofing with email hacking and hijacking. The way I explain it to our customers is that spoofing is simply when someone (usually spammers) sends an email that looks as if it came from one person, when it really came from someone else.

Regardless of what some email providers say, there is no honest and straight forward way to keep people from spoofing your email, unless you have access to the real sender’s mail system. However, there is a way to keep legitimate mail servers from accepting spoofed email by creating an SPF record for your domain.

An SPF record (sender policy framework) in short is a DNS record that you add to your domain’s zone file to specify which hosts are allowed to send mail on behalf of your domain. For the most part you would only want the server hosting your domain to be able to send mail, but hat most of our customers don’t realize is that they unknowingly spoof email all the time! Since ISP’s nowadays block SMTP port 25 for third-party mail servers, a lot of our customers use their ISP to send mail for their domain. This is basically how email is spoofed…you put an email address as the ‘from’ address in an email, and send it from a different mail server. Even though this is legitimate email, they are basically allowing their ISP’s mail servers to send their domain’s email, even though their ISP has no authority or management rights over that email, since the domain is hosted on another server.

We usually require our customers to generate their own SPF records so that they can specify what servers they want to be able to send mail from, that way our hands stay clean if the SPF record causes them to not be able to send email. If you go to www.openspf.org you can easily generate a custom SPF record to add to your DNS zone with little to no hassle. The questions can be a little confusing for newbies, so here’s a quick walkthrough on how to answer them.

Question 1: A-Record

linuxbabu.net's IP address is 75.126.142.72 (srv2.webhostingsuite.com).
Does that server send mail for linuxbabu.net?

The wizard will attempt to resolve the domain to an IP, then do a rDNS on the IP for a hostname. You usually want to say YES unless your mail is hosted on a different server.

Question 2: MX-Record

This wizard found 2 names for the MX servers for linuxbabu.net:

srv2.webhostingsuite.com and linuxbabu.net.
MX servers receive mail for linuxbabu.net.
Do they also send mail from linuxbabu.net?

In most cases, this will be true. Exceptions for this is if you have an irregular MX record modification, or are using another outgoing mail server or domain to send mail.

Question 3: PTR

Do you want to just approve any host whose name ends in linuxbabu.net?

Typically, you do not want to enable this setting unless you have mail accounts set up for subdomains or domains that are similar in ending that need to relay through this domain. Or, if you use a subdomain as your sending host (like mail.domain.com, etc)

Question 4: A subs

Do any other servers send mail from linuxbabu.net?

The answer is usually no. The only other server that would send on behalf of that domain would be the server name (you may need to ask your host for this), but this was already allowed in question 1. The next two fields can be left blank, unless you specifically have information to add to them.

Question 5: Include

Could mail from linuxbabu.net originate through servers belonging to some other domain?

Fill in this field mainly if you are planning on using another mail server or domain (such as your ISP, gmail, etc.) to send mail. Otherwise say no.

Question 6: ~all

Do the above lines describe all the hosts that send mail from linuxbabu.net?

Check your answers and hit yes.
At the bottom of the page you’ll see the nicely-generated SPF record that will look something like this:

"v=spf1 a mx ~all"

Adding the Zone Entry

You can add the SPF record either WHM (if you are on a cPanel server) or manually in the zone file of that domain.

The line will look something like this:

linuxbabu.net. 14400 IN TXT "v=spf1 a mx ~all"

You can then verify the addition by doing a dig on the domain:

dig linuxbabu.netTXT