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Forum Discussion

Benoit_Durand's avatar
Benoit_Durand
Icon for Nimbostratus rankNimbostratus
Feb 10, 2021

Are variables permeable across calls to the same iRule?

Greetings, My question is at the bottom. Some context first.   We have an LTM appliance inline with an ASM appliance (two appliances). LTM front ends the customer side and sends to ASM after. We ...
application delivery
iRules
Benoit_Durand's avatar
Benoit_Durand
Icon for Nimbostratus rankNimbostratus
Feb 11, 2021

So by what you are saying, my variable would have different values each based on the specific session?

 

About your question on ASM and the policy, I wish :) It's a corporate standard applied on all ASM and they don't want to deviate for particular cases :/ That would be too simple.

 

Thanks again.

gersbah's avatar
gersbah
Icon for Cirrostratus rankCirrostratus
Feb 12, 2021

Yes, that is correct. Unless you specifically make a variable global/static, it will not be shared accross sessions.

 

One additional idea: You could disable the violation via iRule, if the ASM policy has ASM iRule events enabled. See here: https://support.f5.com/csp/article/K15573541

Not sure if that would necessarily be "better", I just have an aversion against rewriting requests/responses.

 

PS: One more thing regarding your initial idea. Server response doesn't typically include a host header. I don't think that header replace statement will ever do anything.

If the server response has fully qualified links which are based on the request host header, you may have to rewrite those links in the response content (which could be difficult).