Forum Discussion
NimbostratusAPM parse HTTP Connector json to message box, iRule etc.
Hello all,
I have configured per-session and per-request policies on my APM (APM+LTM) mode and in the process of authentication I want to get some data from external web server. Data is in JSON format. To do that I have created HTTP Connector, assigned it to my per-request policy via subroutine and i can see that the subsession variables are beeing populated correctly via the HTTP Connector (with option save data, i can parse it but the result is the same, just more variables - one per JSON field). In the Overview:Active Session i can see subsession with the following variable with my data:
879cb369./Common/HTTPConnector/XXXXXXXXXXX==.nvp_block.subsession.http_connector.body
Now I wanted to get this data and use it in my authentication flow and iRule but it doesn't work.
First I wanted to test it, by assiginig variable and showing a simple message box in PerReq-policy:
And after that the massage box with: %{perflow.custom} - it doesnt work.
Also tried to just show it in logs with iRule like in documentation ltm rule command ACCESS perflow (f5.com)
So i created an iRule agent in per-request-policy pointing to bellow iRule and attached iRule to my VS:
when ACCESS_PER_REQUEST_AGENT_EVENT {
set $body [ACCESS::perflow get subsession.http_connector.body]
log local0. $body
}
But it doesnt show anything.
I have few questions:
- Is it even possible to access variables in subsession that got retrieved via HTTPConnector and use it further? For example to build JWT for auth?
- Can I assign more than two custom variables from subsession? according to this guide i can only use perflow.custom and perflow.scratchpad?:
Using Variable Assign to populate gating criteria,Using Variable Assign to populate gating criteria,Using Variable Assign to populate gating criteria (f5.com)
Using Variable Assign to populate a perflow variable other than perflow.custom and perflow.scratchpad causes subroutine results to become unreliable.
3. Maybe there is an other option to achieve my goal?
5 Replies
- zamroni777
MVP
you should use node.js based iruleslx, instead of usual tcl based irules, as node.js handles json natively.
there are some examples you can explore:
apm iruleslx - Juergen_Mang
Do not use iRulesLX. You will use a feature that is no more available in Next. If you really want to parse JSON: Json parsing with iRules | DevCentral
Asura2003Thank you for your answers, but i feel that parsing JSON data shouldn't be a problem according to this git project by pmscheffler where he uses HTTP Connector and json data collected with it:
sidebandauth/auth-iRule.tcl at main · pmscheffler/sidebandauth · GitHub
My problem is that i cannot get the data to variable in irule to first show the data in logs (log local0.) to be sure that I get the date i have this simple iRule
when ACCESS_PER_REQUEST_AGENT_EVENT { set id [ACCESS::perflow get perflow.irule_agent_id] if { $id eq "irule_agent_one" } { log local0. "iRule agent $id PRP." } set log1 [ACCESS::perflow get subsession.http_connector.body ] set log2 [ACCESS::perflow get subsession.http_connector.status ] log local0. "Log1 $log1" log local0. "Log2 $log2" }But it shows error in ltm.log:
perflow variable name (subsession.http_connector.body) invalid (line 7) invoked from within "ACCESS::perflow get subsession.http_connector.body "and like i wrote before i have a subsession:
879cb369./Common/HTTPConnector/XXXXXXXXXXX==.nvp_block.subsession.http_connector.body
The variable perflow.irule_agent_id shows in the logs so in my opinion its not like the variable is for example not yet populated?
FabAltostratus
Hello,
I face the same issue. Did you find a solution?
