Need help creating a irule to reverse proxy .

Hi Mel,

an iRule to content-switch just a certain sub directory would look like this...

when HTTP_REQUEST { 
    if { [string tolower [HTTP::uri]] starts_with "/blog/" } then { 
        pool test-reverse-proxy 
    }
}

Does the Blog site has any special requirements, that you need to cover with iRules? (e.g. HOSTNAME rewrite, etc.)

BTW: Keep in mind that this rule would forward the URI "/blog/" but not "/blog".

Cheers, Kai

If I read this correctly, when the customer sends http://www.lightsource.com/blog, you want the backend server to see what is essentially http://lightsource.wpengine.com. The be pedantic, you want the Host: header to change from www.lightsource.com to lightsource.wpengine.com and the request-uri to change from /blog to /. You do not want to perform an HTTP redirect because you want this change to be transparent to the user-agent.

You can solve this on 11.4 or higher using a Local Traffic Policy:

• SOL15085: Overview of the Local Traffic Policies feature

Here is an example:

ltm policy lightsource-rewrite {
    controls { forwarding }
    requires { http }
    rules {
        rule01 {
            actions {
                0 {
                    http-host
                    replace
                    value lightsource.wpengine.com
                }
                1 {
                    http-uri
                    replace
                    path /
                }
            }
            conditions {
                0 {
                    http-host
                    host
                    values { www.lightsource.com }
                }
                1 {
                    http-uri
                    path
                    values { /blog }
                }
            }
            ordinal 1
        }
    }
    strategy first-match
}

Alternatively, you can do the same in an iRule:

when HTTP_REQUEST {
    if { [string tolower [HTTP::host]] eq "www.lightsource.com" and [HTTP::path] eq "/blog" } {
        HTTP::replace Host lightsource.wpengine.com
        HTTP::path "/"
    }
}

If I read this correctly, when the customer sends http://www.lightsource.com/blog, you want the backend server to see what is essentially http://lightsource.wpengine.com. The be pedantic, you want the Host: header to change from www.lightsource.com to lightsource.wpengine.com and the request-uri to change from /blog to /. You do not want to perform an HTTP redirect because you want this change to be transparent to the user-agent.

You can solve this on 11.4 or higher using a Local Traffic Policy:

• SOL15085: Overview of the Local Traffic Policies feature

Here is an example:

ltm policy lightsource-rewrite {
    controls { forwarding }
    requires { http }
    rules {
        rule01 {
            actions {
                0 {
                    http-host
                    replace
                    value lightsource.wpengine.com
                }
                1 {
                    http-uri
                    replace
                    path /
                }
            }
            conditions {
                0 {
                    http-host
                    host
                    values { www.lightsource.com }
                }
                1 {
                    http-uri
                    path
                    values { /blog }
                }
            }
            ordinal 1
        }
    }
    strategy first-match
}

Alternatively, you can do the same in an iRule:

when HTTP_REQUEST {
    if { [string tolower [HTTP::host]] eq "www.lightsource.com" and [HTTP::path] eq "/blog" } {
        HTTP::replace Host lightsource.wpengine.com
        HTTP::path "/"
    }
}

Indeed. The server will see lightsource.wpengine.com fornthe Host header and / as the request-uri path but the user-agent (browser) will not know this, so the URL bar will remain http://www.lightsource.com/blog.

Hi Vernon,

I would add a few things to remind, when it comes to content switching scenarios, where the hostname and/or path needs to be changed.

1.) /blog/ would most likely contain nested ressources and may also reference to other sub directories. So it will be most likely the case that a

starts_with

2.) If the blog website is build on absolute pathes (e.g.

Click me

[STREAM]

3.) If the blog website is build on root pathes that are different (e.g.

),

[STREAM]

4.) If the site is build on relative pathes (e.g.

@Mel: The best thing you could do, is to ask your provider to accept your desired HOSTNAME and provide every ressources below the path of /blog. In this case you won't need to dig into the website content and correct certain things...

Cheers, Kai

Hi Mel,

in my opinion the iRule below would be the last "easy" implementation method.

If this iRules is not working out, then you SHOULD ask your provider to accept the hostname "www.lightsource.com" for the blog website and ask them to store every related content underneath of the path "/blog" without any exeptions.

If the provider can't do / is willing to do this, then you have to dig into the web site content and start to translate included URLs, HTTP-Redirects, etc. But this would then require some deeper HTTP/HTML knowledge and some time to figure out what needs to be changed...

when HTTP_REQUEST {
    if { [string tolower [HTTP::host]] eq "www.lightsource.com" and [HTTP::path] starts_with "/blog" } {
        HTTP::replace Host lightsource.wpengine.com
        pool test-reverse-proxy 
    }
}

Cheers, Kai