Use Case

This is example of simple reverse proxy task done using ISA server which is switching the requests from PROD to TEST setup. The same job can be done on load balancer using simple stream rewrite.

F5 iRules

when HTTP_REQUEST {
			STREAM::disable
			# LTM does not uncompress response content, so if the server has compression enabl ed

			# and it cannot be disabled on the server, we can prevent the server from

			# sending a compressed response by removing the compression offerings from the cli ent
			HTTP::header remove "Accept-Encoding"
			log local0. "Host: [HTTP::host]"
			if { [string tolower [HTTP::host]] equals "www.abc.com.int.xyz.com"} { HTTP::header replace "Host" "www.abc.com"}
			pool POOL1
			log local0. "Setting Pool: POOL1"
			}
			when HTTP_RESPONSE {
			# Check if response type is text
			if {[HTTP::header value Content-Type] contains "text"}{
			# Replace http:// with https://
			STREAM::expression   {@www.abc.com@www.abc.com.int.xyz.com@@www.def.com@www.def
			.com.int.xyz.com@}
			# Enable the stream filter for this response only STREAM::enable
			}

Source: https://devcentral.f5.com/questions/irule-to-redirect-traffic-as-well-as-changing-the-url

NetScaler Solution

add rewrite action replace_host_header replace HTTP.REQ.HEADER("Host")  '"www.abc.com"'

add rewrite policy policy_replace_host_header HTTP.REQ.HEADER("Host").EQ("www.abc.com.int.xyz.com") replace_host_header

Bind Rewrite policy to VSERVER or to Global rewrite bind point on Request Flow.

add rewrite action replace_http_response insert_after_all HTTP.RES.BODY(HTTP.RES.CONTENT_LENGTH) '"www.abc.com.int.xyz.com"' - pattern "www.abc.com"

add rewritepolicy policy_replace_http_response HTTP.RES.HEADER("Content-Type").CONTAINS("text")

replace_http_response

Bind Rewrite policy to specific VSERVER or to Global rewrite bind point on Response flow. Here we are replacing the Host header in the request before it goes to backend. On response path we are replacing the host header specific string in the HTTP body.