Extension:BounceHandler/be-tarask
The BounceHandler extension allows wikis to handle bounce emails efficiently, by:
- Generate a VERP "Variable envelope Return-Path" on
UserMailer::sendemail invocations.
- Bounces can be directly fed to the
bouncehandlerAPI from the MTA using a curl POST request
As a result, users whose address is in error are un-subscribed and they are notified through Echo about this the next time they connect on the wiki. More exactly, their address is un-confirmed, and in case MediaWiki requires confirmed emails no emails will be further sent.
Installation
- Download and move the extracted
BounceHandlerfolder to yourextensions/directory.
Developers and code contributors should install the extension from Git instead, using:cd extensions/
git clone https://gerrit.wikimedia.org/r/mediawiki/extensions/BounceHandler - Add the following code at the bottom of your LocalSettings.php file:
wfLoadExtension( 'BounceHandler' );
- Run the update script which will automatically create the necessary database tables that this extension needs.
Done – Navigate to Special:Version on your wiki to verify that the extension is successfully installed.
Configuration
The extension requires the Mail Transfer Agent (MTA) installed in your mail server to HTTP POST the incoming bounce email to the extension API named as bouncehandler. This can be done by adding the corresponding configurations to your MTA configuration.
Adding bouncehandler router and transport configuration to Exim
You can redirect all your bounce emails to the bouncehandler API directly to do the processing. You can edit your Exim configurations to route all bounce emails to a bounce-handler-router and do HTTP POST to the extension API, which is the recommended method.
Add this to your /etc/exim4/exim4.conf
Under the variable declaration section:
VERP_BOUNCE_LOCALPART_REGEXP = \N^wiki-[\w.]+-\w+-\w+-[+/\w]+$\N
under router configuration:
# Route bounce emails
mw_verp_api:
driver = accept
domains = +verp_domains
condition = ${if match{$local_part}{VERP_BOUNCE_LOCALPART_REGEXP}{true}{false}}
transport = mwverpbounceprocessor
under transports, we need to write the configuration that would HTTP POST to our bouncehandler API
# POST VERP bounce emails to a MediaWiki 'bouncehandler' API 822
mwverpbounceprocessor:
driver = pipe
command = /usr/bin/curl --interface 127.0.0.1 -H 'Host: example.com' http://example.com/api.php -d "action=bouncehandler" -d "format=json" --data-urlencode "email@-" -o /dev/null
user = nobody
group = nogroup
You can find more details in this blog-post "POST-ing bounce email to a Mediawiki API directly from exim".
Adding bouncehandler configuration to Postfix
This section shows how the BounceHandler extension can be configured to handle bounced emails from Postfix, unlike the above section which shows how to do the same with Exim.
First of all, please make sure that Postfix & the package "postfix-pcre" are installed. Once these two installed, open up /etc/postfix/main.cf and add the following in the end of the file:
virtual_alias_maps = pcre:/etc/postfix/virtual
Also, make sure that alias_maps is set to the following:
alias_maps = hash:/etc/aliases
Save & close that file, and then create a new file called etc/postfix/virtual, , and add the following ode
/wiki-[a-z0-9_.]+-[a-z0-9]+-[a-z0-9]+-[a-z0-9+\/=]+@example.com/ curl_email
This will tell Postfix that all the bounced emails (the ones which have return path matching with the above regex expression) should be passed on to the command specified in the alias 'curl_email'.
Now we need to define curl_email as our alias, so save & close this file, open up /etc/aliases and add the following:
curl_email: "|curl --interface 127.0.0.1 -d action=bouncehandler -d format=json --data-urlencode email@- http://example.com/path-to-mediawiki-install/api.php"
Save & close that file, and now type the following commands, to map your /etc/postfix/ to postfix, and then restart postfix:
sudo postmap /etc/postfix/virtual
sudo postalias /etc/aliases
sudo /etc/init.d/postfix reload
sudo /etc/init.d/postfix restart
Save and close this file, and head over to your MediaWiki's LocalSettings.php and make sure add the following line:
$wgJobRunRate = 0;
Once that is done, save and close this file. To test if this works, send an email to an invalid email to your server and then run:
php maintenance/runJobs.php
To check if your email bounces were captured, check the bounce_records table in your MediaWiki database, and /var/log/mail.log for further testing.
API
The BounceHandler extension installs an API bouncehandler to receive the HTTP POST from the mail server.
The API has a parameter email to which the entire bounce email is URL encoded to.
This helps in avoiding the use of a separate bounce collector inbox or other IMAP features for the extension to work.
Example API call:
http://example.org/api.php?action=bouncehandler&email=This%20is%20a%20test%20email This would send a bounce email with the body This is a test email for processing.
VERP address
The extension creates a unique w:VERP address as the Return Path header to every single email send from the wiki installation. The generated VERP address is of the form
wiki-testwiki-2a-nanrfx-Tn14EQZWaotS2XNn@verpwebhost.wmflabs.org
The general template of the generated VERP address is:
$prefix-$wikiName-base36( $userID )-base36( $timestamp )-base64( hash( $algorithm, $key, $data ) )@$email_domain
| Variable | Description |
|---|---|
| $prefix | The prefix applied to every VERP email. Default to wiki |
| $wikiName | The name of the Wiki on which the extension is running |
| $userID | The user id (int) of the recipient from the MediaWiki user table |
| $timestamp | The unix time-stamp value at the time of the VERP address generation |
| $data | The string resulting as the concatenation of $prefix,'-',$wikiId,'-',base_convert( $userID, 10, 36),'-' and base_convert( $timestamp, 10, 36) |
| $algorithm | The hashing php-hmac algorithm used to prepare the hash of $prefix |
| $key | The key used to prepare the hash using the hmac algorithm |
| $email_domain | The domain part of the VERP email address |
Parameters
 | This extension is being used on one or more Wikimedia projects. This probably means that the extension is stable and works well enough to be used by such high-traffic websites. Look for this extension's name in Wikimedia's CommonSettings.php and InitialiseSettings.php configuration files to see where it's installed. A full list of the extensions installed on a particular wiki can be seen on the wiki's Special:Version page. |