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Accepted
João Daniel
Asked: 2012-04-21 05:53:29 +0800 CST

Email to run a bash script

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I have a bash script to restart a service that runs every 3am to guarantee that the service isn't crashed when users require it. However, I need to provide a simpler way for my partner (that isn't from IT area) to run this script when something go wrong.

Is there any way to configure this script to run when a email is sent to some address?

scripting email shell-scripting

3 Answers

  1. Best Answer

    Absolutely!

    In your /etc/aliases file, do this:

    servicerestart: |/usr/local/bin/kickservice

    ... where the email will be sent to [email protected] and the script you've written is the path above. The email and all the headers will be passed to the stdin of your script which you can process as needed (look for password, etc.)

    • 3

  2. If the MTA obeys a ~/.forward file, then you can have procmail process the incoming mail and run a script as soon as the message arrives.

    See http://www.panix.com/~elflord/unix/procmail.html

    For one of my accounts, I have the following ~/.procmailrc

    # procmail tutorial: http://tldp.org/LDP/LG/issue14/procmail.html

PATH=/usr/local/bin:/bin:/usr/bin
MAILDIR=$HOME/Mail
DEFAULT=$HOME/Mail/inbox
LOGFILE=$HOME/procmail.`date +%Y-%m`.log
SHELL=/usr/bin/ksh

MY_XLOOP='X-Loop: [email protected]'
MY_RECIPIENT='[email protected]'


#############################################################################
# 3rd party request processing
# send a copy of the message to the processing script, and carry on
# with the next recipe

:0c
* ^From:.*@3rdparty\.invalid
* ^Subject:.*ABC/DEF.*(Request|Access|Approval)
| $HOME/bin/process_request_email.pl | \
  mailx -s "3rd party request results" $MY_RECIPIENT


#############################################################################
# forward all mail to mailing list
:0
* ! ^$MY_XLOOP
{
    # add a header
    # 'f' = filter: continue processing results of program
    # 'w' = wait for program to return
    # 'h' = pass message headers to program
    :0fwh
    | formail -A "$MY_XLOOP"

    # then forward the message
    # 'c' = send a copy to recipient and continue processing
    :0c
    ! $MY_RECIPIENT
}

# if we get here, then the message has an X-Loop header.
# let it fall into $DEFAULT
    • 2

  3. Absolutely.

    You need:

    • an MTA to receive these mails,
    • a processor to process the mail,
    • rules and restrictions to make sure it can't be abused (easily)

    Based on the requirements, I would advise postfix as the MTA; it has built-in capabilities to execute scripts on message reception, plus easy to configure restrictions on mail reception and connectivity.

    Of course, most sysadmins would just configure cron.

    • 1