HTTP request cloning
Problem this snippet solves:
These iRules send a copy of HTTP request headers and payloads to one or more pool members
These are the current iRule versions of the example from Colin's article.
Code :
########### # First Rule # ########### rule http_request_clone_one_pool { # Clone HTTP requests to one clone pool when RULE_INIT { # Log debug locally to /var/log/ltm? 1=yes, 0=no set static::hsl_debug 1 # Pool name to clone requests to set static::hsl_pool "my_syslog_pool" } when CLIENT_ACCEPTED { if {[active_members $static::hsl_pool]==0}{ log "[IP::client_addr]:[TCP::client_port]: [virtual name] $static::hsl_pool down, not logging" set bypass 1 return } else { set bypass 0 } # Open a new HSL connection if one is not available set hsl [HSL::open -proto TCP -pool $static::hsl_pool] if {$static::hsl_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: New hsl handle: $hsl"} } when HTTP_REQUEST { # If the HSL pool is down, do not run more code here if {$bypass}{ return } # Insert an XFF header if one is not inserted already # So the client IP can be tracked for the duplicated traffic HTTP::header insert X-Forwarded-For [IP::client_addr] # Check for POST requests if {[HTTP::method] eq "POST"}{ # Check for Content-Length between 1b and 1Mb if { [HTTP::header Content-Length] >= 1 and [HTTP::header Content-Length] < 1048576 }{ HTTP::collect [HTTP::header Content-Length] } elseif {[HTTP::header Content-Length] == 0}{ # POST with 0 content-length, so just send the headers HSL::send $hsl "[HTTP::request]\n" if {$static::hsl_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Sending [HTTP::request]"} } } else { # Request with no payload, so send just the HTTP headers to the clone pool HSL::send $hsl "[HTTP::request]\n" if {$static::hsl_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Sending [HTTP::request]"} } } when HTTP_REQUEST_DATA { # The parser does not allow HTTP::request in this event, but it works set request_cmd "HTTP::request" if {$static::hsl_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Collected [HTTP::payload length] bytes,\ sending [expr {[string length [eval $request_cmd]] + [HTTP::payload length]}] bytes total"} HSL::send $hsl "[eval $request_cmd][HTTP::payload]\nf" } } ############# # Second Rule # ############# rule http_request_close_xnum_pools { # Clone HTTP requests to X clone pools when RULE_INIT { # Set up an array of pool names to clone the traffic to # Each pool should be one server that will get a copy of each HTTP request set static::clone_pools(0) http_clone_pool1 set static::clone_pools(1) http_clone_pool2 set static::clone_pools(2) http_clone_pool3 set static::clone_pools(3) http_clone_pool4 # Log debug messages to /var/log/ltm? 0=no, 1=yes set static::clone_debug 1 set static::pool_count [array size static::clone_pools] for {set i 0}{$i < $static::pool_count}{incr i}{ log local0. "Configured for cloning to pool $clone_pools($i)" } } when CLIENT_ACCEPTED { # Open a new HSL connection to each clone pool if one is not available for {set i 0}{$i < $static::pool_count}{incr i}{ set hsl($i) [HSL::open -proto TCP -pool $static::clone_pools($i)] if {$static::clone_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: hsl handle ($i) for $static::clone_pools($i): $hsl($i)"} } } when HTTP_REQUEST { # Insert an XFF header if one is not inserted already # So the client IP can be tracked for the duplicated traffic HTTP::header insert X-Forwarded-For [IP::client_addr] # Check for POST requests if {[HTTP::method] eq "POST"}{ # Check for Content-Length between 1b and 1Mb if { [HTTP::header Content-Length] >= 1 and [HTTP::header Content-Length] < 1048576 }{ HTTP::collect [HTTP::header Content-Length] } elseif {[HTTP::header Content-Length] == 0}{ # POST with 0 content-length, so just send the headers for {set i 0}{$i < $static::pool_count}{incr i}{ HSL::send $hsl($i) "[HTTP::request]\n" if {$static::clone_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Sending to $static::clone_pools($i), request: [HTTP::request]"} } } } else { # Request with no payload, so send just the HTTP headers to the clone pool for {set i 0}{$i < $static::pool_count}{incr i}{ HSL::send $hsl($i) [HTTP::request] if {$static::clone_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Sending to $static::clone_pools($i), request: [HTTP::request]"} } } } when HTTP_REQUEST_DATA { # The parser does not allow HTTP::request in this event, but it works set request_cmd "HTTP::request" for {set i 0}{$i < $static::pool_count}{incr i}{ if {$static::clone_debug}{log local0. "[IP::client_addr]:[TCP::client_port]: Collected [HTTP::payload length] bytes,\ sending [expr {[string length [eval $request_cmd]] + [HTTP::payload length]}] bytes total\ to $static::clone_pools($i), request: [eval $request_cmd][HTTP::payload]"} HSL::send $hsl($i) "[eval $request_cmd][HTTP::payload]\n" } } }
Published Mar 18, 2015
Version 1.0