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dsirrine_23403's avatar
dsirrine_23403
Icon for Nimbostratus rankNimbostratus
Feb 24, 2011

Custom Monitor EAV with Send/Expect script

I am having an issue with my custom monitor where I am attempting to send an e-mail via telnet on port 25 using the send/expect scripted monitor. What I have so far is the following:

 

 

send telnet =IP= 25\r\n

 

expect 220

 

send HELO =IP=\r\n

 

expect 250

 

send MAIL FROM: =email=\r\n

 

expect 250

 

send RCPT TO: =email=\r\n

 

expect 250

 

send DATA\r\n

 

expect 354

 

send SUBJECT:This is a test\r\n

 

send \r\n

 

send Test\r\n

 

send .\r\n

 

expect 250

 

send quit\r\n

 

 

When it sends the telnet *ip* 25, it recieves the 220 ok, however, it then doesn't ignore the rest of the header lines. Is there a method to use regex or a pause statement that I can use to solve this issue in this expect script? Thank you in advance.

 

management
monitoring
  • hwidjaja_37598's avatar
    hwidjaja_37598
    Icon for Altostratus rankAltostratus
    Feb 28, 2011
    I'm not sure whether you can just expect for 250.

     

     

    SMTP uses dash (-) to seperate the status code from the response text while there are more lines remaining, eg. response from SMTP:

     

     

    root@server telnet smtpserver 25

     

    220 Ok

     

    ehlo there

     

    250-Line 1

     

    250-Line 2

     

    250-Line 3

     

    250 This is the end of SMTP response

     

     

    You might need to modify the expect string to retrieve the last line.

     

     

    I'm not good with Expect, but if you need help, I can give you a sample using Perl's Net::SMTP

     

     

  • George_Watkins_'s avatar
    George_Watkins_
    Historic F5 Account
    Mar 03, 2011
    Hi dsirrine,

     

     

    It might be easier to do this as a bash script and run it as an EAV. I wrote an article on EAVs last year and it might help if you are writing any external monitors: http://devcentral.f5.com/Tutorials/TechTips/tabid/63/articleType/ArticleView/articleId/1086366/A-Brief-Introduction-To-External-Application-Verification-Monitors.aspx

     

     

    -George
  • dsirrine_23403's avatar
    dsirrine_23403
    Icon for Nimbostratus rankNimbostratus
    Mar 09, 2011
    I got it to work. I didn't need the initial "send telnet" as the scripted monitor does that to begin with. Unfortunately, I can't use pop/imap/etc as this is to test an exim gateway and can't necessarily "retrieve" the e-mail from the impacted system. doing an "ehlo" on localhost rounds it out nicely. Here's what I ended with: 

    expect 220 
send "HELO localhost\r\n" 
expect "250" 
send "MAIL FROM: address@localhost\r\n" expect "250" 
send "RCPT TO: address@localhost\r\n" 
expect "250" 
send "DATA\r\n" 
expect "354" 
send "SUBJECT:F5 LTM SMTP Health Check\r\n" 
send "\r\n" 
send "This e-mail is generated by the SMTP health check by the F5 LTM.\r\n" 
send ".\r\n" 
expect "250" send "quit\r\n" 
expect "221"

    where
    = a local account that the mailbox has been redirected to /dev/null. If /var is full, I get an error of not being able to write to spooler, otherwise, I get a 250 OK.
  • hooleylist's avatar
    hooleylist
    Icon for Cirrostratus rankCirrostratus
    May 27, 2011
    Hi dsirrine,

     

     

    Thanks a lot for replying with your solution. I added it to the Codeshare here:

     

     

    http://devcentral.f5.com/wiki/default.aspx/AdvDesignConfig/SMTP_scripted_monitor.html

     

     

    Aaron