Forum Discussion

CraigM_17826's avatar
CraigM_17826
Icon for Altocumulus rankAltocumulus
Jul 04, 2012

Ayyway to have entries written to /var/log/ltm to a external syslog server?

Hi,

 

 

Our company has made the decision to move our various web sites into the cloud. Our cloud provider has given us a partition on some form of BigIP running ver 11. Even though we have "manager" access to our paritition we cannot access the ltm log files either via the GUI interface or via shell, in fact we have no ssh access either. Normally on our pair of LTMs I would have a tail running on /var/log/ltm to help in debugging iRules, esp any TCL related errors. The only suggestion the cloud provider had was to tell us to setup a syslog server and redirect the ltm logs to the syslog server. Well I have setup a syslog server but when I asked for help in having the ltm logs for our paritition I redirected, there has been complete silence. So I thought I would ask here.

 

 

I have looked on the wiki and there are quite a few topics on have log entried written to a external syslog server, and I have done some simple log statements to do this, but this is not quite what I need because I would like to see TCL errors as well and I can't see any way to log these. So I guess if it can be done it's now from an iRule, or it can't be done. So is it possible?

 

tia

 

 

Craig

 

 

application delivery
dev
devops
iRules
  • hoolio's avatar
    hoolio
    Icon for Cirrostratus rankCirrostratus
    Jul 04, 2012
    Hi Craig,

     

     

    You can log directly from an iRule using HSL::open or log remote. However, that won't capture runtime errors with iRules as those aren't generated from the iRule itself-but TMM. You could testing this to confirm. But I think you'll need to configure syslog-ng to log /var/log/ltm entries to your remote syslog server. You can check these articles for details:

     

     

    HSL (10.1+)

     

    https://devcentral.f5.com/wiki/iRules.hsl__open.ashx

     

     

    log remote

     

    https://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/190/iRules-Update-New-options-for-the-log-command.aspx

     

     

    You can also search on AskF5 for "remote syslog" for LTM to get instructions on how to configure syslog-ng for remote logging.

     

     

    Aaron
  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jul 04, 2012

    this is my testing.  

     

    LTM 9.4.2+: Custom Syslog Configuration by Deb  

    https://devcentral.f5.com/s/articles/LTM-9-4-2-Custom-Syslog-Configuration

     

    [root@ve10:Active] config  b syslog include
SYSLOG - Include Data: none
 
[root@ve10:Active] config  b syslog include '"
> destination remote_server {
>   udp(\"192.168.206.55\" port (514));
> };
> filter f_rule {
>   match(\"_rule\");
> };
> log {
>   source(s_syslog_pipe);
>   filter(f_local0);
>   filter(f_rule);
>   destination(remote_server);
> };"'
[root@ve10:Active] config  b syslog include
SYSLOG - Include Data:
destination remote_server {
  udp("192.168.206.55" port (514));
};
filter f_rule {
  match("_rule");
};
log {
  source(s_syslog_pipe);
  filter(f_local0);
  filter(f_rule);
  destination(remote_server);
};
 
[root@ve10:Active] config  b rule test_rule list
rule test_rule {
   when CLIENT_ACCEPTED {
   set test "HTTP::uri"
   eval $test
}
 
/var/log/ltm
 
Jul  4 12:43:03 local/tmm err tmm[5111]: 01220001:3: TCL error: test_rule  - Operation not supported (line 2)     invoked from within "HTTP::uri"     ("eval" body line 1)     invoked from within "eval $test"
 
syslog
 
C:\>nc -l -u -p 514
<131>Jul  4 12:43:03 local/tmm err tmm[5111]: 01220001:3: TCL error: test_rule  - Operation not supported (line 2)     invoked from within "HTTP::uri"     ("eval" body line 1)     invoked from within "eval $test"
  • CraigM_17826's avatar
    CraigM_17826
    Icon for Altocumulus rankAltocumulus
    Jul 04, 2012

    Thanks for the quick replies. One more question, if I get this going, will only entries relating to our partition be captured or will I see entries from all partitions on this LTM? At the moment there is only one other company. It was explained to me that the reason why they wouldn't give me LOG access was because I would see log entries from other users in different partitions. So is there a way I can filter out entries only relating to our paritiion to keep them happy?

     

     

    tia

     

     

    Craig

     

     

  • nitass's avatar
    nitass
    Icon for Employee rankEmployee
    Jul 04, 2012
    in my example, i filter log by using part of irule name i.e. "_rule". i am not sure if partition name is included in log. if yes, we use partition name to filter log.
  • CraigM_17826's avatar
    CraigM_17826
    Icon for Altocumulus rankAltocumulus
    Jul 05, 2012

    Hi Nitass and Hoolio,

     

     

    thanks for your comments/suggestions. I'm working with our cloud provider now on this.

     

     

    Craig