ProxyPass v10/v11

Problem this snippet solves:

iRule to replace the functionality of Apache Webserver ProxyPass and ProxyPassReverse functions. Allows you to do hostname and path name modifications as HTTP traffic passes through the LTM. This optimized version requires TMOS v10 or higher. If you are using APM for authentication on the virtual server, please use the ProxyPass_for_use_with_APM iRule instead.

(Full documentation follows the iRule.)

For use with TMOS v9, see ProxyPass v8.2

Note: In 10.1+ you can use an internal data group to store the ProxyPass configuration. Ignore the comments to the contrary in the instructions as these were for pre-10.1 releases.

Please post questions or fixes for this iRule in the iRules forum to get the fastest response. Thanks Aaron.

Introduction Sometimes it is desirable to have a different look and feel to your website on the outside than you have in the inside. You may want www.company.com/usa/ to internally go to the server usa.company.com. You may want support.company.com to go internally to abc123.company.com/web/support. This can create a few issues - sometimes the web server expects to see a certain hostname (i.e. for name-based virtual hosting) or will use the internal hostname and/or path when sending a redirect to the clients.

These problems can be overcome with the Apache webserver using the ProxyPass module which can translate the URL on the way into the server, and the ProxyPassReverse module which can un-translate header fields such as Location in the case of a redirect.

Now you can accomplish this with an iRule. The ProxyPass iRule translates incoming requests in a flexible manner and untranslates the Location, Content-Location, and/or URI headers in the response back to the client. ProxyPass also rewrites the domain and path in cookies set by the server.

Page Content Modification In addition, this rule will perform basic page modification as needed (this feature is disabled by default but can be enabled in the RULE_INIT event). Using the example from the introduction, if the page content contains a link to http://abc123.company.com/web/support/viewticket.html, the iRule will modify that to be http://support.company.com/viewticket.html. Here are some examples:

< a href=http://www.domain.com/path/file.html> will be modified assuming the incoming request was matched by the ProxyPass iRule and the inside hostname was www.domain.com and the inside path was /path.

< a href="page2.html"> will not need to be modified as this is a URL already relative to the path. Even relative URLs such as < a href="../page2.html"> will work as long as it does not try to go above the top-level directory defined by the ProxyPass rules.

You must have a stream profile defined on any virtual servers the rule is applied to in order to enable the page modification feature.

Virtual Server The first step to using the ProxyPass iRule is to define the rule on your BIG-IP and associate it with one or more Virtual Servers. Note that each virtual server MUST have an HTTP profile defined (doesn't matter which one). I also highly recommend applying a OneConnect profile, especially if you will be choosing pools with ProxyPass. It also must have a stream profile associated with it if you want to uncomment the page modification code. The rule will work on HTTP sites as well as HTTPS sites where the SSL is terminated on the BIG-IP (i.e. a client-side SSL profile is defined).

Data Groups You can apply the ProxyPass rule to any virtual server that you want to do translations on. But just applying the rule will have no effect unless you define the translations you want done. This is done by defining specific Data Groups.

The ProxyPass iRule uses Data Groups which are created and managed by going to Local Traffic / Virtual Servers / iRules on the left menu bar in the BIG-IP GUI. Then choose the "Data Group List" tab at the top of the screen. Here you can create the data groups used by this rule. For 10.0.x, the data groups must be External, type "String", and Read-only. For 10.1 and higher, the data group can be internal or external with name=value pairings.

In order to use this rule on a virtual server you must apply the rule to the virtual server and create a data group named ProxyPassXYZ where "XYZ" needs to be the name of the virtual server. If both of these conditions are not met then the rule will not work for that virtual server.

ProxyPassXYZ Data Groups If your virtual server is named XYZ and has the ProxyPass iRule associated with it, it will look for a data group named ProxyPassXYZ. Assuming that class is found, for each new HTTP request, the rule will find the one row that matches the hostname/path used in the request. For example, the data group may contain 4 entries (each line below is one string in the data group):

"www.usa.company.com/support" := "support.company-internal.com:8080/usa",
"www.usa.company.com/" := "www.company-internal.com:8080/usa",
"www.japan.company.com/" := "www.company-internal.com:8080/japan",
"/" := "www.company-internal.com:8080/others",

A request need not match any entries - if no entries match then the iRule will have no effect. But each request will only match at most one entry and that will be the entry with the most specific left-hand-side. Entries with hostnames specified on the left-hand-side will be matched before entries without hostnames. If multiple entries match then the entry with the longest path name on the left-hand-side will be used. The example above lists entries from most-specific to least-specific, just as the rule will process them, but in your actual data group the order of the entries does not matter.

In the example above, requests to http://www.usa.company.com/support will match the first entry and have the host header changed to "support.company-internal.com:8080" and the URI will be rewritten so that the string /support at the beginning of the URI will be changed to /usa.

Furthermore, requests to http://www.usa.company.com/ will match the second entry as long as the URI does not begin with "/support" in which case it would match the first entry. In that case the Host header will be changed to "www.company-internal.com:8080" and whatever URI the client sends in will be prepended with "/usa". Likewise all requests to http://www.japan.company.com/ will match the third entry and have the Host header changed to "www.company-internal.com:8080" and the URIs would be prepended with "/japan".

Finally, all other requests that hit this example virtual server would match the least-specific rule which is simply "/" -- all URIs begin with "/" and thus all requests will match the fourth entry if they did not match any others. Remember that a catch-all entry is not required, but in this example we want to prepend the URI of all other requests with "/others".

Note that the ProxyPass iRule does not actually alter the destination of the requests by default. In the examples above all of the requests would go to the default pool regardless of the entries they match. The hostnames and ports specified in the right-hand entry is only used to modify the Host header. To alter the destination pool see the next section.

Dynamic Pool Selection You may also specify an alternate pool as a second item in the right-hand value of the entry. This is optional any items in the list without a pool name will just use the default pool associated with the virtual server. For example:

"/support" := "support.company.com/ SupportPool",
"/downloads" := "downloads.company.com/ DownloadPool",
If the pool name is not valid the user will get an error and you should see an error message in /var/log/ltm.

Dynamic SNAT You can optionally define a ProxyPassSNATs data group. This will allow you to use different SNAT IP based on which pool you send traffic to. The ProxyPassSNATs data group is shared by all virtual servers but will only have an effect if the selected pool is listed in the data group. The format of this data group (internal string type) is:

Pool1 W.X.Y.Z
Pool2 automap

Dynamic ServerSSL Profiles You can optionally define a ProxyPassSSLProfiles data group and apply a generic serverssl profile to the virtual server. This will allow you to use different serverssl profiles based on which pool you send traffic to. The ProxyPassSSLProfiles data group is shared by all virtual servers but will only have an effect if the selected pool is listed in the data group and a generic serverssl is applied to the virtual server. The format of this data group (internal string type) is:

Pool1 ServerSSLProfile1
Pool2 ServerSSLProfile2

Regular Expressions New in v10: you may also use regular expressions and backreferences when building your rule set.

"/" := "=www.company.com/(.*?)/=$1.company.com/=",

As you see, instead of a regular server-side entry, we have "=regex=replace=". Basically, in order for the regex to be run, the left-hand side must match the client host/path (just "/" in this case, which will always match unless something more specific matches). Once this happens, the client host and URI are combined into a form similar to www.domain.com/path and the regular expression is run a against it. If the regular expression does not match, ProxyPass does not alter the request. If it does match, the clientside path becomes the match string and the serverside path becomes the replace string. Within this replace string you can use $1 through $9 as back-references to grouped items in the original regular expression. So, the example above, entry is equivalent to all of these entries:

"www.company.com/sales" := "sales.company.com/",
"www.company.com/support" := "support.company.com/",
"www.company.com/employment" := "employment.company.com/",

Debugging You can debug your ProxyPass rules by setting the static::ProxyPassDebug variable at the top of the rule to 1 (or 2 for more verbose debugging). Once you do this you can SSH to the BIG-IP and run the command "tail -f /var/log/ltm" to see what ProxyPass is doing to your requests.

Code :

# ProxyPass iRule, Version 10.9
# Nov 26 2012. Date
# THIS VERSION REQUIRES TMOS v10 or higher. Use ProxyPass v8.2 for TMOS 9.x.

# This version does not work with APM-enabled virtual servers, please
# download ProxyPass 10.2APM for this use case.

# Created by Kirk Bauer
# https://devcentral.f5.com/s/wiki/default.aspx/iRules/ProxyPassV10.html
# (please see end of iRule for additional credits)

# Purpose:
# iRule to replace the functionality of Apache Webserver ProxyPass and
# ProxyPassReverse functions.  It allows you to perform host name and path name
# modifications as HTTP traffic passes through the LTM.  In other words, you
# can have different hostnames and directory names on the client side as you
# do on the server side and ProxyPass handles the necessary translations.

# NOTE: You should not need to modify this iRule in any way except the settings
# in the RULE_INIT event.  Just apply the iRule to the virtual server and
# define the appropriate Data Group and you are done.  If you do make any
# changes to this iRule, please send your changes and reasons to me so that
# I may understand how ProxyPass is being used and possibly incorporate your
# changes into the core release. 

# Configuration Requirements
# 1) The ProxyPass iRule needs to be applied to an HTTP virtual server or
# an HTTPS virtual server with a clientssl profile applied to it.
# 2) A data group (LTM -> iRules -> Data Groups tab) must be defined with
# the name "ProxyPassVIRTUAL" where VIRTUAL is the name of the virtual server
# (case-sensitive!).  See below for the format of this data group (class).
# For 10.0.x, you must use an EXTERNAL data group.
# 3) You must define a default pool on the virtual server unless you specify
# a pool in every entry in the data group.  
# 4) If you are using ProxyPass to select alternate pools, you must define
# a OneConnect profile in most cases!
# 5) ProxyPass does not rewrite links embedded within pages by default, just 
# headers.  If you want to change this, edit the $static::RewriteResponsePayload variable in RULE_INIT
# and apply the default stream profile to the virtual server.

# Data Group Information
# For 10.0.x, you must define an external data group (type=String, read-only) which loads 
# from a file on your BIG-IP.  For 10.1 and higher you can use an internal string data group with name=value pairings.
# The format of the file is as follows:
#    "clientside" := "serverside",
# or
#    "clientside" := "serverside poolname",
# The clientside and serverside fields must contain a URI (at least a "/") and
# may also contain a hostname.  Here are some examples:
#    "/clientdir" := "/serverdir",
#    "www.host.com/clientdir" := "internal.company.com/serverdir",
#    "www.host.com/" := "internal.company.com/serverdir/",

# Notes:
# 1) You can optionally define a ProxyPassSNATs data group to SNAT based
# on the pool selected.
# 2) You can optionally define a ProxyPassSSLProfiles data group to select
# a serverssl profile based on the pool selected.
# 3) You can also use regular expressions which is documented on DevCentral.

when RULE_INIT {
# Enable to debug ProxyPass translations via log messages in /var/log/ltm
# (2 = verbose, 1 = essential, 0 = none)
set static::ProxyPassDebug 0

# Enable to rewrite page content (try a setting of 1 first)
# (2 = attempt to rewrite host/path and just /path, 1 = attempt to rewrite host/path)
set static::RewriteResponsePayload 0
}

when CLIENT_ACCEPTED {
# Get the default pool name.  This is used later to explicitly select 
# the default pool for requests which don't have a pool specified in 
# the class.
set default_pool [LB::server pool]

# The name of the Data Group (aka class) we are going to use. 
# Parse just the virtual server name by stripping off the folders (if present)
set clname "ProxyPass[URI::basename [virtual name]]"

if { $static::ProxyPassDebug > 1 } {
log local0. "[virtual name]: [IP::client_addr]:[TCP::client_port] -> [IP::local_addr]:[TCP::local_port]"
}
}

when HTTP_REQUEST {
# "bypass" tracks whether or not we made any changes inbound so we
# can skip changes on the outbound traffic for greater efficiency.
set bypass 1

# Initialize other local variables used in this rule
set orig_uri "[HTTP::uri]"
set orig_host "[HTTP::host]"
set log_prefix "VS=[virtual name], Host=$orig_host, URI=$orig_uri"
set clientside ""
set serverside ""
set newpool ""
set ppass ""

if {! [class exists $clname]} {
log local0. "$log_prefix: Data group $clname not found, exiting."
pool $default_pool
return
} else {
set ppass [class match -element "$orig_host$orig_uri" starts_with $clname]
if {$ppass eq ""} {
# Did not find with hostname, look for just path
set ppass [class match -element "$orig_uri" starts_with $clname]
}
if {$ppass eq ""} {
# No entries found
if { $static::ProxyPassDebug > 0 } {
log local0. "$log_prefix: No rule found, using default pool $default_pool and exiting"  
}
pool $default_pool
return
}
}

# Store each entry in the data group line into a local variable
set clientside [getfield $ppass " " 1]
set serverside [string trimleft [getfield $ppass " " 2 ] "{" ]
set newpool [string trimright [getfield $ppass " " 3 ] "}" ]

# If serverside is in the form =match=replace=, apply regex
if {$serverside starts_with "="} {
set regex [getfield $serverside "=" 2]
set rewrite [getfield $serverside "=" 3]
if {[regexp -nocase $regex "$orig_host$orig_uri" 0 1 2 3 4 5 6 7 8 9]}{
# The clientside becomes the matched string and the serverside the substitution
set clientside $0
set serverside [eval set X $rewrite]
} else {
pool $default_pool
return
}
}

if {$clientside starts_with "/"} {
# No virtual hostname specified, so use the Host header instead
set host_clientside $orig_host
set path_clientside $clientside
} else {
# Virtual host specified in entry, split the host and path
set host_clientside [getfield $clientside "/" 1]
set path_clientside [substr $clientside [string length $host_clientside]]
}
# At this point $host_clientside is the client hostname, and $path_clientside
# is the client-side path as specified in the data group

set host_serverside [getfield $serverside "/" 1]
set path_serverside [substr $serverside [string length $host_serverside]]
if {$host_serverside eq ""} {
set host_serverside $host_clientside
}
# At this point $host_serverside is the server hostname, and $path_serverside
# is the server-side path as specified in the data group

# In order for directory redirects to work properly we have to be careful with slashes
if {$path_clientside equals "/"} {
# Make sure serverside path ends with / if clientside path is "/"
if {!($path_serverside ends_with "/")} {
append path_serverside "/"
}
} else {
# Otherwise, neither can end in a / (unless serverside path is just "/")
if {!($path_serverside equals "/")} {
if {$path_serverside ends_with "/"} {
set path_serverside [string trimright $path_serverside "/"]
}
if {$path_clientside ends_with "/"} {
set path_clientside [string trimright $path_clientside "/"]
}
}
}

if { $static::ProxyPassDebug } {
log local0. "$log_prefix: Found Rule, Client Host=$host_clientside, Client Path=$path_clientside, Server Host=$host_serverside, Server Path=$path_serverside"  
}

# If you go to http://www.domain.com/dir, and /dir is a directory, the web
# server will redirect you to http://www.domain.com/dir/.  The problem is, with ProxyPass, if the client-side
# path is http://www.domain.com/dir, but the server-side path is http://www.domain.com/, the server will NOT
# redirect the client (it isn't going to redirect you to http://www.domain.com//!).  Here is the problem with
# that.  If there is an image referenced on the page, say logo.jpg, the client doesn't realize /dir is a directory
# and as such it will try to load http://www.domain.com/logo.jpg and not http://www.domain.com/dir/logo.jpg.  So
# ProxyPass has to handle the redirect in this case.  This only really matters if the server-side path is "/",
# but since we have the code here we might as well offload all of the redirects that we can (that is whenever
# the client path is exactly the client path specified in the data group but not "/").
if {$orig_uri eq $path_clientside} {
if {([string index $path_clientside end] ne "/") and not ($path_clientside contains ".") } {
set is_https 0
if {[PROFILE::exists clientssl] == 1} {
set is_https 1
}
# Assumption here is that the browser is hitting http://host/path which is a virtual path and we need to do the redirect for them
if {$is_https == 1} {
HTTP::redirect "https://$orig_host$orig_uri/"
if { $static::ProxyPassDebug } {
log local0. "$log_prefix: Redirecting to https://$orig_host$orig_uri/"
}
} else {
HTTP::redirect "http://$orig_host$orig_uri/"
if { $static::ProxyPassDebug } {
log local0. "$log_prefix: Redirecting to http://$orig_host$orig_uri/"
}
}
return
}
}

if {$host_clientside eq $orig_host} {
if {$orig_uri starts_with $path_clientside} {
set bypass 0
# Take care of pool selection
if {$newpool eq ""} {
pool $default_pool
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: Using default pool $default_pool"
}
set newpool $default_pool
} else {
pool $newpool
if { $static::ProxyPassDebug > 0 } {
log local0. "$log_prefix: Using parsed pool $newpool (make sure you have OneConnect enabled)"
}
}
}
}

# If we did not match anything, skip the rest of this event
if {$bypass} {
return
}

# The following code will look up SNAT addresses from 
# the data group "ProxyPassSNATs" and apply them. 
# 
# The format of the entries in this list is as follows: 
# 
#   
# 
# All entries are separated by spaces, and both items 
# are required.
set class_exists_cmd "class exists ProxyPassSNATs"
if {! [eval $class_exists_cmd]} {
return
}

set snat [findclass $newpool ProxyPassSNATs " "]

if {$snat eq ""} { 
# No snat found, skip rest of this event
return 
}

if { $static::ProxyPassDebug > 0 } { 
log local0. "$log_prefix: SNAT address $snat assigned for pool $newpool"  
} 

snat $snat
}

when HTTP_REQUEST_SEND {
# If we didn't match anything, skip the rest of this event
if {$bypass} {
return
}

# The following code does the actual rewrite on its way TO 
# the backend server. It replaces the URI with the newly 
# constructed one and masks the "Host" header with the FQDN 
# the backend pool server wants to see. 
# 
# If a new pool or custom SNAT are to be applied, these are 
# done here as well. If a SNAT is used, an X-Forwarded-For 
# header is attached to send the original requesting IP 
# through to the server. 

if {$host_clientside eq $orig_host} {
if {$orig_uri starts_with $path_clientside} {
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: New Host=$host_serverside, New Path=$path_serverside[substr $orig_uri [string length $path_clientside]]"
}
clientside { 
# Rewrite the URI
HTTP::uri $path_serverside[substr $orig_uri [string length $path_clientside]]
# Rewrite the Host header
HTTP::header replace Host $host_serverside
# Now alter the Referer header if necessary
if { [HTTP::header exists "Referer"] } {
 set protocol [URI::protocol [HTTP::header Referer]]
 if {$protocol ne ""} {
  set client_path [findstr [HTTP::header "Referer"] $host_clientside [string length $host_clientside]]
  if {$client_path starts_with $path_clientside} {
if { $static::ProxyPassDebug > 1 } {
 log local0. "$log_prefix: Changing Referer header: [HTTP::header Referer] to $protocol://$host_serverside$path_serverside[substr $client_path [string length $path_clientside]]"
}
HTTP::header replace "Referer" "$protocol://$host_serverside$path_serverside[substr $client_path [string length $path_clientside]]"
  }
 }
}
  }
}
}

# If we're rewriting the response content, prevent the server from using
#compression in its response by removing the Accept-Encoding header
#from the request.  LTM does not decompress response content before
#applying the stream profile.  This header is only removed if we're
#rewriting response content.
clientside {
if { $static::RewriteResponsePayload } {
if { [HTTP::header exists "Accept-Encoding"] } {
HTTP::header remove "Accept-Encoding"
if { $static::ProxyPassDebug > 1} {
log local0. "$log_prefix: Removed Accept-Encoding header"
}
}
}
HTTP::header insert "X-Forwarded-For" "[IP::remote_addr]"
}
}

when HTTP_RESPONSE {
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: [HTTP::status] response from [LB::server]"
}

if {$bypass} {
# No modification is necessary if we didn't change anything inbound so disable the stream filter if it was enabled

# Check if we're rewriting the response
if {$static::RewriteResponsePayload} {
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: Rewriting response content enabled, but disabled on this response."
}

# Need to explicity disable the stream filter if it's not needed for this response
# Hide the command from the iRule parser so it won't generate a validation error
#when not using a stream profile
set stream_disable_cmd "STREAM::disable"

# Execute the STREAM::disable command.  Use catch to handle any errors. Save the result to $result
if { [catch {eval $stream_disable_cmd} result] } {
# There was an error trying to disable the stream profile.
log local0. "$log_prefix: Error disabling stream filter ($result). If you enable static::RewriteResponsePayload, then you should add a stream profile to the VIP.  Else, set static::RewriteResponsePayload to 0 in this iRule."
}
}

# Exit from this event.
return
}

# Check if we're rewriting the response
if {$static::RewriteResponsePayload} {
# Configure and enable the stream filter to rewrite the response payload
# Hide the command from the iRule parser so it won't generate a validation error
#when not using a stream profile
if {$static::RewriteResponsePayload > 1} {
set stream_expression_cmd "STREAM::expression \"@$host_serverside$path_serverside@$host_clientside$path_clientside@ @$path_serverside@$path_clientside@\""
} else {
set stream_expression_cmd "STREAM::expression \"@$host_serverside$path_serverside@$host_clientside$path_clientside@\""
}
set stream_enable_cmd "STREAM::enable"
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: \$stream_expression_cmd: $stream_expression_cmd, \$stream_enable_cmd: $stream_enable_cmd"
}

# Execute the STREAM::expression command. Use catch to handle any errors. Save the result to $result
if { [catch {eval $stream_expression_cmd} result] } {
# There was an error trying to set the stream expression.
log local0. "$log_prefix: Error setting stream expression ($result). If you enable static::RewriteResponsePayload, then you should add a stream profile to the VIP.  Else, set static::RewriteResponsePayload to 0 in this iRule."
} else {
# No error setting the stream expression, so try to enable the stream filter
# Execute the STREAM::enable command.  Use catch to handle any errors. Save the result to $result
if { [catch {eval $stream_enable_cmd} result] } {
# There was an error trying to enable the stream filter.
log local0. "$log_prefix: error enabling stream filter ($result)"
} else {
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: Successfully configured and enabled stream filter"
}
}
}
}

# Fix Location, Content-Location, and URI headers
foreach header {"Location" "Content-Location" "URI"} {
set protocol [URI::protocol [HTTP::header $header]]
if { $static::ProxyPassDebug > 1 } {
log local0. "$log_prefix: Checking $header=[HTTP::header $header], \$protocol=$protocol"
}
if {$protocol ne ""} {
set server_path [findstr [HTTP::header $header] $host_serverside [string length $host_serverside]]
if {$server_path starts_with $path_serverside} {
if { $static::ProxyPassDebug } {
log local0. "$log_prefix: Changing response header $header: [HTTP::header $header] with $protocol://$host_clientside$path_clientside[substr $server_path [string length $path_serverside]]"
}
HTTP::header replace $header $protocol://$host_clientside$path_clientside[substr $server_path [string length $path_serverside]]
}
}
}

# Rewrite any domains/paths in Set-Cookie headers
if {[HTTP::header exists "Set-Cookie"]}{
array unset cookielist
foreach cookievalue [HTTP::header values "Set-Cookie"] {
set cookiename [getfield $cookievalue "=" 1]
set namevalue ""
set newcookievalue ""
foreach element [split $cookievalue ";"] {
set element [string trim $element]
if {$namevalue equals ""} {
set namevalue $element
} else {
if {$element contains "="} {
set elementname [getfield $element "=" 1]
set elementvalue [getfield $element "=" 2]
if {[string tolower $elementname] eq "domain"} {
set elementvalue [string trimright $elementvalue "."]
if {$host_serverside ends_with $elementvalue} {
if {$static::ProxyPassDebug > 1} {
log local0. "$log_prefix: Modifying cookie $cookiename domain from $elementvalue to $host_clientside"
}
set elementvalue $host_clientside
}
append elementvalue "."
}
if {[string tolower $elementname] eq "path"} {
if {$elementvalue starts_with $path_serverside} {
if {$static::ProxyPassDebug > 1} {
log local0. "$log_prefix: Modifying cookie $cookiename path from $elementvalue to $path_clientside[substr $elementvalue [string length $path_serverside]]"
}
set elementvalue $path_clientside[substr $elementvalue [string length $path_serverside]]
}
}
append newcookievalue "; $elementname=$elementvalue"
} else {
append newcookievalue "; $element"
}
}
} 
set cookielist($cookiename) "$namevalue$newcookievalue"
}
HTTP::header remove "Set-Cookie"
foreach cookiename [array names cookielist] {
HTTP::header insert "Set-Cookie" $cookielist($cookiename)
if {$static::ProxyPassDebug > 1} {
log local0. "$log_prefix: Inserting cookie: $cookielist($cookiename)"
}
}
}
}

# Only uncomment this event if you need extra debugging for content rewriting.
# This event can only be uncommented if the iRule is used with a stream profile.
#when STREAM_MATCHED {
#if { $static::ProxyPassDebug } {
#log local0. "$log_prefix: Rewriting match: [STREAM::match]"
#}
#}

# The following code will look up SSL profile rules from 
# the Data Group ProxyPassSSLProfiles" and apply 
# them. 
# 
# The format of the entries in this list is as follows: 
# 
#   
# 
# All entries are separated by spaces, and both items 
# are required.  The virtual server also will need to
# have any serverssl profile applied to it for this to work.
when SERVER_CONNECTED { 
if {$bypass} {
return
}

set class_exists_cmd "class exists ProxyPassSSLProfiles"
if {! [eval $class_exists_cmd]} {
return
}

set pool [LB::server pool]  
set profilename [findclass $pool ProxyPassSSLProfiles " "]

if {$profilename eq ""} { 
if { [PROFILE::exists serverssl] == 1} {
# Hide this command from the iRule parser (in case no serverssl profile is applied) 
set disable "SSL::disable serverside" 
catch {eval $disable}
}
return 
}

if { $static::ProxyPassDebug > 0 } { 
log local0. "$log_prefix: ServerSSL profile $profilename assigned for pool $pool"  
} 
if { [PROFILE::exists serverssl] == 1} {
# Hide these commands from the iRule parser (in case no serverssl profile is applied)
set profile "SSL::profile $profilename"
catch {eval $profile}
set enable "SSL::enable serverside" 
catch {eval $enable}
} else {
log local0. "$log_prefix: ServerSSL profile must be defined on virtual server to enable server-side encryption!"  
}
}

# ProxyPass Release History
#v10.9: Nov 26, 2012: Used URI::basename to get the virtual server name. Thanks to Opher Shachar for the suggestion.
#Replaced indentations with tabs intead of spaces to save on characters
#v10.8: Oct 25, 2012: Updated the class name to remove the folder(s) (if present) from the virtual server name. 
# This assumes the ProxyPass data group is in the same partition as the iRule.
#v10.7: Oct 24, 2012: Changed array set cookielist {} to array unset cookielist as the former does not clear the array.
# Thanks to rhuyerman@schubergphilis.com and Simon Kowallik for pointing out the issue and this wiki page with details: http://wiki.tcl.tk/724 
#v10.6: Oct 14, 2012: Updated how the protocol is parsed from URLs in request and response headers to fix errant matches
#v10.5: Feb 2, 2012: Removed extra stream profile $result reference for debug logging.
#v10.4: Nov 23, 2011: Removed an extra colon in sever HTTP::header replace commands to prevent duplicate headers from being inserted
#v10.3: Sep 27, 2010: Moved rewrite code to HTTP_REQUEST_SEND to work with WebAccelerator
# Fixed bug with cookie rewrites when cookie value contained an "="
#v10.2: Jun 04, 2010: Can handle individual file mappings thanks to Michael Holmes from AZDOE
# Also fixed bug with directory slash logic
#v10.1: Oct 24, 2009: Now CMP-friendly! (NOTE: use ProxyPass v8.2 for TMOS v9.x)
#v10.0: May 15, 2009: Optimized for external classes in v10 only (use v8.2 for TMOS v9.x)
# Added support for regular expressions and backreferences for the translations.
# v8.2: Jun 04, 2010: Fixed bug with directory slash logic
# v8.1: May 15, 2009: Added internal redirects back in (removing them was a mistake)
# v8.0: May 13, 2009: pulled in changes submitted by Aaron Hooley (hooleylists gmail com)
# TMOS v10 support added.  Cookie domain/path rewriting added.
# v7.0: May 6, 2008: added optional serverssl contributed by Joel Moses
# v6.0: Jan 15, 2008: Small efficiency change
# v5.0: Jul 27, 2007: Added Referer header conversions
# v4.0: Jul 27, 2007: Added optional debugging flag
# v3.0: Jul 20, 2007: Added SNAT support contributed by Adam Auerbach
# v2.0: May 28, 2007: Added internal directory redirects and optional stream profile
# v1.0: Feb 20, 2007: Initial Release

Tested this on version:

10.0
Published Mar 18, 2015
Version 1.0
  • I am trying to stick one of our SSO enable apps behind our F5 and trying to use ProxyPass. I tested other apps and they work however our sso app fails with this error: Login could not be processed because the original cookie identifying the session was not passed by browser.

     

    I can see in the ProxyPass output that cookies does get altered but it looks correct to me. Any suggestions on what this could be?

     

    If I comment out the entire section that modifies cookie then the app works. going to turn on some additional debugging to see what it is.

     

    thanks!

     

  • I am trying to rewrite URL from internal to external by applying the mask on header. It is working as expected using below irule however if I select some hyperlink or option, its showing actual url information which we would like to prevent that, as client should not recognize where they are getting redirected.In our example, I am forwarding users who are trying to access test.abc.com/xyz/ to , till here it is working as expected but after it got redirected, if I select any option or hyperlinks, its no rewrite the URL information.

     

    when HTTP_REQUEST { if { [HTTP::host] eq "test.abc.com" and [HTTP::uri] contains "/xyz/" } { if {[string tolower [HTTP::uri]] contains "/xyz"}{ set uri [string range [HTTP::uri] 4 end] HTTP::uri $uri HTTP::header replace host ";; pool testGoogle log local0. "[IP::client_addr]:[TCP::client_port]: Replacing Host with http://[HTTP::host]HTTP::uri" }}}

     

  • Hey!

     

    has anyway to maintain URL PATH after redirect?

     

    i need to keep PATH from clientside to ServerSide.

     

    i saw in log that what i did, didnt change path for server side.

     

    clientside = xpto.company.com.br

     

    serverside = xpto.company.corp

     

    " URI=/: Found Rule, Client Host=Xpto.company.com.br, Client Path=/, Server Host=Xpto.company.corp, Server Path=/ Feb 27 12:23:12 bigip1 info tmm[10187]: Rule /Common/ProxyPassVS_SAS_FW_Mdvx : VS=/Common/VS_SAS_FW_Mdvx, Host=xpto.company.com.br, URI=/: Using default pool /Common/Pool_SAS Feb 27 12:23:12 bigip1 info tmm[10187]: Rule /Common/ProxyPassVS_SAS_FW_Mdvx : VS=/Common/VS_SAS_FW_Mdvx, Host=xpto.company.com.br, URI=/SASDrive/: Found Rule, Client Host=xpto.company.com.br, Client Path=/, Server Host=xpto.copmany.corp, Server Path=/ Feb 27 12:23:12 bigip1 info tmm[10187]: Rule /Common/ProxyPassVS_SAS_FW_Mdvx : VS=/Common/VS_SAS_FW_Mdvx, Host=xpto.company.com.br, URI=/SASDrive/: Using default pool /Common/Pool_SAS"

     

    how can I get it?

     

  • @Hariharan_Padmanabhan:

    If you are using this ProxyPass iRule, Please see Comment 5 in the instructions:

     5) ProxyPass does not rewrite links embedded within pages by default, just
     headers.  If you want to change this, edit the $static::RewriteResponsePayload variable in RULE_INIT
     and apply the default stream profile to the virtual server.
     Data Group Information
     For 10.0.x, you must define an external data group (type=String, read-only) which loads
     from a file on your BIG-IP.  For 10.1 and higher you can use an internal string data group with name=value pairings.
     The format of the file is as follows:
     "clientside" := "serverside",
     or
     "clientside" := "serverside poolname",
     The clientside and serverside fields must contain a URI (at least a "/") and
     may also contain a hostname.  Here are some examples:
     "/clientdir" := "/serverdir",
     "[www.host.com/clientdir"](//www.host.com/clientdir) := "internal.company.com/serverdir",
     "[www.host.com/"](//www.host.com/) := "internal.company.com/serverdir/",
    

    If you are creating your own iRule, then you may want to start by reviewing the

    STREAM::
    commands here STREAM.

  • @Diogo Rocha

    I'm not sure I follow what you mean.

    • Where is the redirect happening?
    • From your back-end server?
    • What isn't being maintained?
    • The logs you provided show that the LTM is honoring the URI Clientside -> Serverside
    1. Initial request matching your rule

      xpto.company.com.br := xpto.company.corp

      URI=/: Found Rule, Client Host=Xpto.company.com.br, Client Path=/, Server Host=Xpto.company.corp, Server Path=/
      URI=/: Using default pool /Common/Pool_SAS
      
    2. The second request maintains the URI of

      /SASDrive/
      clientside -> serverside.

      URI=/SASDrive/: Found Rule, Client Host=xpto.company.com.br, Client Path=/, Server Host=xpto.copmany.corp, Server Path=/
      URI=/SASDrive/: Using default pool /Common/Pool_SAS"
      

    So, please be clear on what you have observed is not working.

  • hello,

     

    i used this irule on v11 and v12 (LTM) without any problems, now i migrated to v13 and i see a delay between CLIENT_ACCEPT and HTTP_REQUEST of 1 second.

     

    Did something change in v13 that would explain such delay?

     

    greetings

     

    edit. nvm this is caused by changed tcp profiles

  • Have anyone ever tested this native functionality mentioned by Denny_Payne?  "You should no longer need to use the proxypass iRule in v12. The same functionality can be natively accomplished with a Rewrite profile that does URI translation."

    Is there any article/example using it? I'm really curious about it. I'm about to migrate some ancient F5s running code 10.2 to a new platform running code 16.2. The old one has some VIPs using ProxyPass. Well, if we have a native solution and don't need to deal with this old ProxyPass iRule, that would be great.

    You should no longer need to use the proxypass iRule in v12. The same functionality can be natively accomplished with a Rewrite profile that does URI translation.

    Thanks.