Admin tools: Link crawler robot

Maintained by Picture of Catalyst IT Catalyst IT, Picture of Brendan Heywood Brendan Heywood, Picture of Daniel Thee Roperto Daniel Thee Roperto
An admin tool robot crawler which scans your moodle for broken, large or slow links.
109 sites
18 fans

It is an admin tool with a moodle cron task, but it reaches into your moodle via curl effectively from outside moodle, and scrapes each page, parses it and follows links. By using this architecture it will only find broken links that actually matter to students. Because it comes in from outside it needs to authenticate and has a dependancy on the moodle-auth_basic plugin. It is recommended that you setup a dedicated 'robot' user who has readonly access to all the site pages you wish to crawl. You should give the robot similar capabilites that real students will have.


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Picture of Catalyst IT
Catalyst IT (Lead maintainer)
Picture of Daniel Thee Roperto
Daniel Thee Roperto: Coder at Catalyst IT Australia
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  • Picture of Dan Marsden
    Tue, 19 Jul 2016, 7:30 AM
    Cool tool! - David Mudrak reviewed a previous version of this plugin implemented as a local plugin - I can see the issues he raised have been resolved and it works well for me, nice work!
  • Picture of Jon Bolton
    Sun, 7 Aug 2016, 2:27 AM
    It does work well, but I narrowed this plugin down to causing a fatal error in a completely different area of Moodle. In Site Admin > Plugins > Activity Modules > Glossary, there is the option to edit and hide/show Display formats. Both the update and hide/show icons result in the message "Coding error detected, it must be fixed by a programmer: PHP catchable fatal error". I uninstalled all my additional plugins, one by one, and this one was the only one that caused this error. No idea why, I’m not a developer, but happy to test it / replicate it if needed.

    Running Moodle 3.1+ (Build: 20160616) on php5/apache2 with mysql (5.5.47-0+deb6u1)
  • Picture of Brendan Heywood
    Mon, 7 Nov 2016, 6:34 AM
    FYI the bug found by Jon above was fixed a while back
  • Picture of Max Linzmeier
    Wed, 14 Dec 2016, 3:41 PM
    There's currently a bug in file 'auth.php' on line 174. The key should be 'auth_basic', not 'auth_saml2'. Otherwise it isn't possible to save the values on settings page. smile
  • Picture of Daniel Thee Roperto
    Wed, 14 Dec 2016, 4:14 PM
    Hi Max,

    Thank you for reporting this, we updated the auth_basic plugin.

    You can find it here:


  • Picture of Max Linzmeier
    Thu, 15 Dec 2016, 4:27 PM
    Hi Daniel,

    cool, thank you! But there is another problem in function crawler->reset_for_recrawl. I created a new issue on GitHub. Thank you!

  • Picture of Allison Soo
    Tue, 2 May 2017, 10:51 AM
    Great tool with huge potential!
    The report is displayed on screen currently. Any plan to add an export option so the users could download a copy of report in csv/excel format for offline analysis and data manipulation? This will greatly help to search and identify broken links in a particular course efficiently without scrolling through page by page. Also, any part of the report can be distributed to the respective course developer(s) whom do not have administrator access to review the broken links offline.
  • Picture of Brendan Heywood
    Wed, 3 May 2017, 8:26 AM
    thanks Allison,

    I've logged that new feature idea here:
  • Picture of Mary-Anne Camillo
    Fri, 9 Jun 2017, 7:11 AM
    Does anyone have any privacy/security
    issues using this?
  • Picture of Brendan Heywood
    Tue, 13 Jun 2017, 7:40 AM
    hi Mary-Anne,

    There should be no privacy issues, as the crawler results are only visible to admin and course managers by default. Also what the robot can see is completely configurable via moodle's capabilities so if anything sensitive is being scraped you can turn it off. Also the robot is only interested in links, it ignores all other content. So the only real privacy issue could be visibility of an external link, but either way all content that is scraped is visible to normal course admins / students anyway.

    The main security issue is making sure the robots credentials aren't leaked as then someone could gain access to whatever the robot can see. But this is exactly the same as managing credentials for any other user. The robot user should not have any write permissions to anything at all. If you need to roll the password for the robot this is trivial.

    If you, or anyone, identify any privacy or security issues I've missed please ensure they are logged here:


  • Picture of Gero Lückemeyer
    Tue, 12 Sep 2017, 5:36 PM
    Hi Brendan,

    great idea and something I assume many people were waitiing for. Thanks for providing the plugin!

    Your solution technically seems to work from the comments here, but I think at least for some it answers the wrong (business) question. In our university, responsibility for maintaining course content such as external links does not lie with the (poor) administrator or cron job running the plugin, but with the trainer of the respective course.

    For full business utility, the plugin should sort the dead links by trainer and course and send an email to every trainer with his or her broken links, ordered by course and - if possible - givie the title in the course along with the link target.

    I assume that due to the limited capabilities of individual Moodle plugins the email functionality would require an additional plugin. Anyway, the individual email per trainer solves any data privacy issues that might arise from sending the full report to all trainers - even in the very critical Germany.

    Please let me know what you think of this idea.

    Thank you very much, best regads,

  • Picture of Brendan Heywood
    Wed, 13 Sep 2017, 8:08 AM
    hi Gero,

    This plugin currently provides reports at both the site level and also add filtered reports at the course level so that each course coordinator can see just what affects their courses. See Course > Course administration > Reports > Link crawler robot > (4 new reports).

    If they find issues they can fix it on the spot, and then from those course level reports flag a url for recrawling and these get a higher priority than the background en-masse crawling. We could very easily add an email report within this plugin if we wanted to - but for the client that sponsored this plugin that was actually undesirable. Broadly I would like to evolve this plugin to have a similar set of features and reports to the Google webmaster tool aka Search console.

    I'd happy to implement some sort of email based reporting, as long as it was opt in and was configurable at the site level. If you want to sponsor this new feature please contact us:

  • Picture of Rajas Joshi
    Sun, 10 Dec 2017, 3:23 PM
    will the latest version of this plugin work with moodle 3.3.2?
  • Picture of Brendan Heywood
    Mon, 11 Dec 2017, 6:45 AM
    This plugin requires the basic auth plugin which in turn needs to updated to support the new auth settings api. This isn't much work if you wanted to sponsor it. I have another client interested in this so support should be added in a couple months if you are happy to wait.
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