Documentation

Implementation Overview

ImageEngine is a pull based Image CDN. A pull based CDN will pull an image from the origin on demand. There is no need to upload images anywhere.

CNAME your own domain

The domain name of your choice will, through DNS configuration, direct requests to ImageEngine’s powerful edge servers.

If the requested image, in a version matching the capabilities of the requesting device, is not already in edge cache, ImageEngine will generate a new derivative in realtime. This derivative is cached at the edges with a unique cache key based on the capabilities of the requesting device or browser.

In the event that this image is not in ImageEngine cache at all, typically the very first time an image is requested, the image will be fetched from the origin. In these cases you may experience that the image request is redirected to a xxxx.miss.imgeng.in host. This is completely normal for full cache misses. This behaviour can be turned on/of in the control panel.

Once fully operational, the ImageEngine CDN cache typically handles 98% of the traffic, while the origin servers see only 2% of the actual traffic.

# Integration Methods

There are three different ways to access images optimized by ImageEngine:

# 1. ImageEngine Hostname

CNAME your own domain

All domain names you register will get their own *.imgeng.in hostname.

If you register the domain name images.foo.com, for example, the ImageEngine hostname will be images.foo.com.imgeng.in.

The ImageEngine Hostname is mapped to the same origin as the domain name. Images can be served directly from this hostname.

This is an easy way to get started if you don’t have immediate access to edit DNS records.

Example:

<img src="//images.foo.com.imgeng.in/image.jpg">

For accounts in the Basic plan, the ImageEngine hostname will look something like this: zzzxxxyyy.cdn.imgeng.in, where the first part is a randomly generated value. HTTPS is supported out of the box. These types of ImageEngine hostnames can not be referred to in a CNAME DNS record.

# 2. DNS CNAME Record

CNAME your own domain

You may want to serve images from a domain name you own. In this case you can create a CNAME record in your DNS for your domain name and point it to the ImageEngine Hostname (see above).

You manage the domain name and DNS settings in the control panel.

This is the recommended and preferred way to use ImageEngine in a production environment.

Example:

<img src="//images.foo.com/image.jpg">

# 3. Prefix Origin URL

CNAME your own domain

You can prefix any image URL with an ImageEngine domain name (both a “CNAMEd”- and a *.imgeng.in hostname).

The origin is then defined by the URL appended to the ImageEngine hostname.

This is a great option if you have multiple origins you want to serve through the same domain name. It is also a great method for testing ImageEngine with different environments. In the control panel it is possible to restrict which origins can be prefixed.

Example:

<img src="http://images.foo.com/http://origin.com/image.jpeg">

Or

<img src="http://images.foo.com.imgeng.in/http://origin.com/image.jpeg">