The addition of routes

[josephdenne]

The addition of a conditional routing concept to DADI CDN, whereby you can configure rules to select different recipes based on information derived about a user.

You can think of a route as a colleciton of recepes that are dynamically chosen on the basis of known data.

Recepe selection can be made on the basis of:

• The device being used
• Network speed
• Current location (continent, region, country, city)
• Language

For example: if I requested image X on an iPhone, I would receive recipe Y, but if I requested image X on a laptop I would receive recipe Z.

For device and language lookup, DADI CDN will use device sniffing of request headers. For example: https://www.npmjs.com/package/mobile-detect

For location and network lookup DADI CDN will make use of the DADI location and netspeed APIs.

Note: the DADI location API requires a clientId and secret and as such the use of location and network speed will be optional, configured within the main config file

Routes will be held in /workspace/routes as JSON files on disk, as per recipes.

Example route:

{
    "route": "thumbnail",
    "conditions": [
        {
            "condition": {
                "device": "desktop",
                "network": "broadband",
                "location": "london",
                "language": "en"
            },
            "recipe": "desktop-london-en-thumbnail-xlarge"
        },
        {
            "condition": {
                "device": "desktop",
                "network": "mobile"
            },
            "recipe": "mobile-thumbnail-xlarge"
        },
        {
            "condition": {
                "device": "mobile",
                "network": "mobile"
            },
            "recipe": "mobile-thumbnail"
        }
    ],
    "else": "thumbnail"
}

Routes will specify one or more conditions against which to match a user request, along with a recipe to load in the event of a positive match, and a fallback recipe in the event that no matches are found.

Route files will be named in the format {ROUTE-NAME}.json, where {ROUTE-NAME} is the URL string for the route and where {ROUTE-NAME} also matches the route within the JSON.

A route is called in the same way as a recipe. For example:

http://youdomain.com/example-route-name/image-filename.png

Note: routes take precedences over recepes, so in the event that there is a route called "thumbnail" and a recepe called "thumbnail", it is the route that is parsed.