Hi All, I currently have an in production virtual server on my F5 which also has a SSL certification. My organisation would like to be able to use the same URL to take advantage of the certificate, but to reroute to another pool of test servers which using a /test on the url. So for example www.example.com to go to the existing pool members (poollive) and www.example.com/test to go to a new test pool of members (pooltest) I've created an irule to try to get this to do this procedure. Can anyone confirm if this irule is correct, or needs some additional work. when HTTP_REQUEST { if { [HTTP::uri] contains "test" } pool pooltest } else { pool poollive } } Can someone advise if this would be correct? Thanks,

Looks like a reasonable start... I'd suggest this minor change... if { [HTTP::uri] starts_with "/test" } That's a little more specific and would avoid the situation where a URL with "test" in the middle is sent to the wrong pool (e.g. /application/testpage.htm should go to poollive) Once you start using logic like this, it's common to have more URI patterns that need to be sent to another pool. When that happens, I'd recommend going to a format like the following. As the list grows, this tends to be easier to read. (*note this example code is untested) switch -glob [HTTP::uri] { "/test*" - "/another_url_that_shouldnt_be_live/index.htm" { pool pooltest } "/someOtherPool*" {pool poolother) default { pool poollive } } See here for more info about switch... http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/244/Switch-Gone-Wild-Using-Wildcards-with-the-Tcl-switch-command.aspx

Hi Natalia, I would also recommend using the following statement; [string tolower [HTTP::uri]] instead of just [HTTP::uri]. This will ensure your strings in the switch match up to the URI without being concerned about capitalization. Bhattman

I use yet another variation similar to what Peter and Bhattman suggested: switch -glob [string tolower [HTTP::path]] { "/test*" - "/another_url_that_shouldnt_be_live/index.htm" { pool pooltest } "/someOtherPool*" {pool poolother) default { pool poollive } } I use HTTP::path, which just excludes the querystring, since I don't need that to makemy switching decision. I have about 8 paths in my switch statement and it works very well.

Hi Guys, Thanks for your comments. I'm now ready to execute the irule on my F5, but would like to clarify the configuration. switch -glob [string tolower [HTTP::path]] { "/test*" { pool pooltest } default { pool poollive } } Pool live is the default which all connections need to go to except when /test URL is requested. This is only temporary for a migration process, and just wondered if the above will do the trick? I'm just conceous as this is on a live environment. Thanks, Natalia

yep, that should work fine. If you want another layer of feel-good before applying to your live virtual, you could create a dummy virtual with the same parameters and apply your rule there to make sure it does as you expect before applying to the prod traffic.

Irule for rerouting to different pools

11 Replies

Peter_72728
Nimbostratus
Aug 01, 2011
Looks like a reasonable start...

I'd suggest this minor change...

if { [HTTP::uri] starts_with "/test" }

That's a little more specific and would avoid the situation where a URL with "test" in the middle is sent to the wrong pool (e.g. /application/testpage.htm should go to poollive)

Once you start using logic like this, it's common to have more URI patterns that need to be sent to another pool. When that happens, I'd recommend going to a format like the following. As the list grows, this tends to be easier to read. (*note this example code is untested)

switch -glob [HTTP::uri] { "/test*" - "/another_url_that_shouldnt_be_live/index.htm" { pool pooltest } "/someOtherPool*" {pool poolother) default { pool poollive } }

See here for more info about switch...

http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/244/Switch-Gone-Wild-Using-Wildcards-with-the-Tcl-switch-command.aspx
The_Bhattman
Nimbostratus
Aug 01, 2011
Hi Natalia,

I would also recommend using the following statement;

[string tolower [HTTP::uri]] instead of just [HTTP::uri].

This will ensure your strings in the switch match up to the URI without being concerned about capitalization.

Bhattman
Pconlan_71037
Altocumulus
Aug 01, 2011
I use yet another variation similar to what Peter and Bhattman suggested:

switch -glob [string tolower [HTTP::path]]

{

"/test*" -

"/another_url_that_shouldnt_be_live/index.htm" { pool pooltest }

"/someOtherPool*" {pool poolother)

default {

pool poollive

}

}

I use HTTP::path, which just excludes the querystring, since I don't need that to makemy switching decision. I have about 8 paths in my switch statement and it works very well.
Natalia_Wolosec
Nimbostratus
Aug 15, 2011
Hi Guys,

Thanks for your comments.

I'm now ready to execute the irule on my F5, but would like to clarify the configuration.

switch -glob [string tolower [HTTP::path]]

{

"/test*" { pool pooltest }

default {

pool poollive

}

}

Pool live is the default which all connections need to go to except when /test URL is requested.

This is only temporary for a migration process, and just wondered if the above will do the trick?

I'm just conceous as this is on a live environment.

Thanks,

Natalia
JRahm
Admin
Aug 15, 2011
yep, that should work fine. If you want another layer of feel-good before applying to your live virtual, you could create a dummy virtual with the same parameters and apply your rule there to make sure it does as you expect before applying to the prod traffic.
nwoloseckyj_684
Nimbostratus
Aug 24, 2011
Hi It's Natalia,

Unfortunately when I applied that irule it told me I didnt have an up to date version. running v9.

So can you confirm this would do the same thing?

when HTTP_REQUEST {

if { [HTTP::uri] contains "\new" }{

pool new

} else {

pool default

}

}
hooleylist
Cirrostratus
Aug 24, 2011
The switch command should work in any LTM version. What's the exact iRule you tried and what error did you see?

Aaron
nwoloseckyj_684
Nimbostratus
Aug 24, 2011
switch -glob [string tolower [HTTP::path]]

{

"/new*" { pool new}

default {

pool default}

}
nwoloseckyj_684
Nimbostratus
Aug 24, 2011
This is the error I get:

01070151:3: Rule [OSS_TestPool] error:

line 1: [command is not valid in the current scope] [switch -glob [string tolower [HTTP::path]] ]

line 1: [command is not valid in the current scope] [string tolower [HTTP::path]]

line 1: [command is not valid in the current scope] [HTTP::path]

line 2: [undefined procedure:

"/new*" { pool oss-pci-dmz-pool }

default {

pool oracle10g-oss-pool

}

] [{

"/new*" { pool oss-pci-dmz-pool }

default {

pool oracle10g-oss-pool

}

hooleylist

Cirrostratus

Aug 24, 2011

Can you put it in the HTTP_REQUEST event?


when HTTP_REQUEST {

   switch -glob [string tolower [HTTP::path]] {
      "/new*" { pool new}
      default {
         pool default
      }
   }
}

Aaron

Forum Discussion

Irule for rerouting to different pools

11 Replies

Recent Discussions

ASM instance creation

[ASM] - what is "Browser Challange file" ?

[ASM] - HTML5 Cross-Domain Request Enforcement - CLI command

Reverse Proxy Not Behaving

Stable Firmware for F5

Related Content

Copper SFP Differences

iRules Style Guide

iRule for sending traffic to a different pool based on the Hostname.

Http monitor on different port

Hey ChatGPT, can you write iRules?