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"
}
}
}