MailIn

MailIn provides a simple engine for transforming e-mail alerts from 3rd party software into NAV events. These events can then be processed by NAV’s event- and alert systems.

See also the original blueprint specification for MailIn.

Configuring MailIn

These examples all assume your NAV installation prefix is the default /usr/local/nav.

Redirecting mail to the MailIn program

The mail transfer agent on your NAV server must be configured to accept SMTP connections from outside the server, or no messages will come through.

Pick an e-mail address on your NAV server to send 3rd party alerts to, for example mailin@nav.example.org. Mail received at this address should be piped through the mailin.py program. This can usually be accomplished by adding an e-mail alias to /etc/aliases, like this:

cat >> /etc/aliases <<EOF
mailin: "| /usr/local/nav/bin/mailin.py"
EOF
newaliases

Also, for mailin.py to work properly, it needs write access to its log file. Your mail delivery agent will likely run the program under a user ID that has no write access to the file. Consult your MDA documentation; a typical choice for Postfix on a Debian system is to run external commands as the user nobody. Make sure to change ownership of the log file:

chown nobody /usr/local/nav/var/log/mailin.log

Selecting plugins

Add the plugins you want to use to the plugins variable in your mailin.conf file. For example:

plugins =
  nav.mailin.plugins.whatsup
  nav.mailin.plugins.kake

The plugins will be tried in the order they are listed in the config file, so if the whatsup plugin accepts the message here, kake will never be called.

Alert message templates

Each plugin will define its own set of event and alert types for its domain. The example plugins come with their own alert message templates in the /usr/local/nav/etc/alertmsg/ directory, but if you write your own plugins with your own event and alert types, you will need to write your own alert message templates in this directory as well.

Here’s an example for the whatsup plugin, which defines the whatsup event type. Each event it generates contains the subject and body variables, which can be referenced in the alert message templates:

  1. For email alerts there’s alertmsg/whatsup/default-email.txt:

    Subject: {{ subject }}
    
    {{ body }}

    For email alerts, the first line of the template should always start with Subject:, which causes the rest of that line to be used as the subject header of the sent email.

  2. For SMS alerts there’s alertmsg/whatsup/default-sms.txt:

    {{ subject }}
    

    The subject variable is usually short and appropriate for a quick SMS alert.