For this guide, we will assume the following:

• you have a website at www.example.com
• you want to serve the images on www.example.com from a CDN, and the name of this CDN domain will be i.example.com
• the CDN you want to use is Cloudfront, yet serve the images from the i.example.com domain name.
• dyyyzzz123.cloudfront.net is the Cloudfront distribution domain name you have

Step 1 - Set up a new Cloudfront distribution:

To do this, login to your AWS Console homepage, typically at https://console.aws.amazon.com/console/home.

Click Create Distribution, and select the Download option.

Step 2 - Origin and Default Options:

For Origin Domain Name enter www.example.com. Leave the options at HTTP Only, and Port 80 (unless you have a good reason not to).

The Create Default Behavior screen should be left as is (unless you have a good reason not to).

Step 3 - Distribution Details:

For Alternate Domain Names (CNAMES) enter i.example.com.

For Default Root Object you can specify a file to be displayed if a non-existent resource is requested, i.e. to handle 404s. So for example enter handler.html here, where handler.html can contain whatever message or content you want.

Click to the Review step, and complete.

Note the domain name of the distribution you just created – in our example, its dyyyzzz123.cloudfront.net.

Step 4 – CNAME setup:

Logon to your webserver, or wherever you have your DNS records handled. Here we will setup the CNAME records we specified in Step 3 above.

We are going to edit the zone file for example.com, to add i.example.com as a CNAME (alias) record.

I use Bind9 as my DNS server, and on my Debian server my DNS zone files are located in /var/lib/named/etc/bind. It may be different on your setup.

In /var/lib/named/etc/bind, edit the zone file example.com.db file.

Add the following to the bottom of the file:

i.example.com IN CNAME dyyyzzz123.cloudfront.net

What this does is create i.example.com as an alias of our Cloudfront distribution – in other words, content from dyyyzzz123.cloudfront.net will be transparently served to the user as content from i.example.com.

Step 5 – Apache setup:

The next step is to set the CNAME i.example.com as a ServerAlias of the domain example.com.

So in /etc/apache2/sites-enabled/example.com, add the ServerAlias line directly below the ServerName line, as per this:

ServerName example.com

ServerAlias i.example.com

Step 6 – restart services:

Reload Bind and Apache:

/etc/init.d/apache2 reload

/etc/init.d/bind9 reload

Going back to your AWS console, check that the distribution setup is complete. It usually takes about 15 mins, and once State is green and “Enabled”, as well as Status being “Deployed”, you are good!

Step 7 – deploy and test:

That’s it, you should now be serving assets on i.example.com, via the dyyyzzz123.cloudfront.net distribution, and which were sourced from www.example.com.

E.g. in the doc_root of www.example.com, e.g. /var/www/example, place a new image named image_name.jpg.

If you now go to i.example.com/image_name.jpg, you will see the image in your browser. But how do we know it is coming from Cloudfront?

One of the easiest ways to do so is to use CURL. Open a command line and enter this:

curl -I -0 i.example.com/image_name.jpg

You should see quite clearly the header information for Cloudfront, e.g. X-Cache: Hit from cloudfront or Via …. Cloudfront etc.

Useful Resources/Further Reading

Some useful resources are listed below if you wish to read further or dig deeper into this.

• Amazon starting guide
• Good starting guide
• http://aws.amazon.com/sdkforphp/
• AWS SDK for PHP Tips and Tricks
• Migrating to the AWS SDK for PHP
• All Articles & Tutorials
• Video of Cloudfront Console
• http://www.zytrax.com/books/dns/ch8/cname.html
• Way to implement private video

This code snippet below is code I used to make use of Zend’s SOAP web service library, and shows a typical usage of __autoload(). Basically, if a class being instantiated doesn’t exist in PHP’s include path, __autoload() is called before throwing a fatal error. So this gives you a chance to pull the necessary classes in, so to speak.


function __autoload($class) {
if ($class!='this') {
preg_match_all('/(\w+_)+(\w+)/',$class,$matches);

require_once($base_string);
}
}


Firstly, check what modules are enabled:

apache2ctl -t -D DUMP_MODULES

Secondly, with Apache2 its very easy to actually add a module:

a2enmod headers

DUMP_MODULES will show you mod_headers now, or you can should see it in etc/apache2/mods-enabled.

The suggestion is to use SplFileObject::DROP_NEW_LINE or SplFileObject::SKIP_EMPTY to handle this.

However, I find I often need to use both to achieve the desired result of ignoring blank or empty lines. To achieve this, you need to use a bitmask in your setflags argument.

A value of ’7′ corresponds to both SplFileObject::DROP_NEW_LINE AND SplFileObject::SKIP_EMPTY, e.g.

$file = new SplFileObject($path);
$file->setFlags(7);

setFlags(15) would correspond to a bitmask for DROP_NEWLINE, SKIP_EMPTY, READ_CSV.


#SR does global replacement in html files, replacing its first parameter by
#its second parameter--use with extreme caution!

find ./ -name '*.html' -print | while read i
do
sed "s/$1/$2/g" $i >$i.bak && mv $i.bak $i
done


To use this, simply execute the command via:

./SR term_to_find term_to_replace_with

As a slight tweak, and what I find more useful, is to add a third input param, for example to switch on the file names you want to replace:

#SR does global replacement in files specified in STDIN as third parameter, replacing its first parameter by
#its second parameter--use with extreme caution!

find ./ -name "*.$3" -print | while read i
do
sed "s/$1/$2/g" $i >$i.bak && mv $i.bak $i
done

For example, to replace image1.jpg with image2.jpg, in all css files, run this:

./SR image1.jpg image2.jpg css

To do so, first upload the image you want to use, and a thumbnail of it to the wp-content/themes/NEW_THEME_NAME/images/headers directory.

Then, in wp-content/themes/NEW_THEME_NAME/functions.php edit the register_default_headers function, to replace ‘sunset’ below with your new image details:

'sunset' => array(
'url' => '%s/images/headers/sunset.jpg',
'thumbnail_url' => '%s/images/headers/sunset-thumbnail.jpg',
/* translators: header image description */
'description' => __( 'Sunset', 'copied_twenty_theme' )
),


Then go to Appearance -> Theme -> Headers in your Admin panel, and you should be able to select the new image as header.

I trawled various forums, and got the usual “do a full re-install” etc, or disable and re-enable all plugins blah blah blah.

The solution is here – its elegant, simple and a one-liner: add the below line to your wp-config.php file.

define(‘CONCATENATE_SCRIPTS’, false );

For me, it happened on a Dell machine, and it is incredibly annoying.

So, if you have enabled dual-booting, with say a Windows and Linux partition, all seems fine booting into your Ubuntu install, until that is, you boot up Windows, and then try to subsequently boot up your machine to either Windows or Linux.

What happens is a message:

module name not found, press any key

Of course pressing the “any key” does nothing, and you are unable to boot up any OS from the HDD.

There are a series of excellent links on this, all worth a look, as your situation may have slight differences to some mentioned scenarios within the links below:

• http://ubuntuforums.org/showthread.php?t=1501591
• http://ubuntuforums.org/showthread.php?t=1560177
• http://sourceforge.net/apps/mediawiki/bootinfoscript/index.php?title=Boot_Problems:Windows_Writes_To_MBR
• http://ubuntuforums.org/showthread.php?t=1343851&page=2

What is happening is that certain Dell software, e.g. Datasafe, modify the MBR, and your GRUB gets corrupted/needs to be re-installed.

Quick Solution:

As described in links above, for a quick fix to allow you boot in again, load up your Live CD, e.g. ubuntu install CD you can download easily (using a Knoppix boot for example from the CD drive), and run from the CD drive. Then, open a terminal shell, and do the following:

sudo mount /dev/sda3 /mnt
sudo grub-install –recheck –root-directory=/mnt /dev/sda

In the above, sda3 represents whatever partition your Linux install is on, so will likely be different for you – that should be the only thing you need to change above.

Once done, you can boot up again as per usual, until of course you log into Windows again!

So long-term solution is to identify all Dell proprietary software (most listed in links above and http://download.cnet.com/ccleaner/ and http://forum.notebookreview.com/dell-xps-studio-xps/406492-how-do-i-remove-dells-datasafe.html), fully delete them using CC Cleaner for example, re-boot using the Live CD GRUB trick one final time, and then you should be good!

To get it back, just do as described here, but watching out for the typos in the commands as printed there, namely:

gconftool –recursive-unset /apps/panel

rm -rf ~/.gconf/apps/panel

pkill gnome-panel

Viola!!