F5 migration from HA proxy

OK let's GO We will begin with maintenance page:

First you have to import all your files (page, png, css, gif):

• Create your FILE: System ›› File Management ›› Import...
• then create your ifile: Local Traffic ›› iRules : iFile List ›› New iFile...

And use this simple Irule for maintenance page that trigged when you have an error 5** for example:

when HTTP_REQUEST { 

 --- set variable --- 
set host [HTTP::host]
set uri [HTTP::uri]
set alert 0
 --- set variable --- 

 --- Trigged maintenance for Node down --- 
if {[active_members [LB::server pool]] < 1 } {
    if {$uri == "/maintenance_page.html"} {
         do nothing
    } elseif {$uri == "/css/yourcss.css" ||  $uri == "/img/yourgif.gif" || $uri == "/img/yourpng.png" } {
         do nothing
    } else {
        HTTP::redirect "https://$host/maintenance_page.html"
    }
}

 --- load maintenance page object --- 
switch -glob [HTTP::uri] {
    "/maintenance_page.html" { HTTP::respond 200 content [ifile get "/Common/maintenance_page.html"] noserver "Content-Type" "text/html" "Cache-Control" "no-cache, must-revalidate"
        set alert 1}
    "/css/yourcss.css" { HTTP::respond 200 content [ifile get "/Common/yourcss.css"] noserver "Content-Type" "text/css" "Cache-Control" "no-cache, must-revalidate"
        set alert 1}
    "/img/yourgif.gif" { HTTP::respond 200 content [ifile get "/Common/yourgif.gif"] noserver "Content-Type" "image/gif" "Cache-Control" "no-cache, must-revalidate"
        set alert 1}
    "/img/yourpng.png" { HTTP::respond 200 content [ifile get "/Common/yourpng.png"] noserver "Content-Type" "image/png" "Cache-Control" "no-cache, must-revalidate"
        set alert 1}
    default {
         do nothing 
    }
}
}


when HTTP_RESPONSE {
 --- Trigged maintenance for 500 
if {[HTTP::status] starts_with "5"} {
    HTTP::respond 200 content [ifile get "/Common/maintenance_page.html"] noserver "Content-Type" "text/html" "Cache-Control" "no-cache, must-revalidate"
} 
}