Removing Canonical Link Tags (canonical_link_tag) from Discourse

Recently I learned that Discourse serves a totally different application to crawlers, like GoogleBot for example. I learned this when writing a Discourse plugin code to alter the meta <link rel="canonical"> tag based on if the topic was imported from the legacy forum or created new in the Discourse forum.

Much of this journey of discovery is chronicled here::

For the time being, I decided to simply strip the canonical tags from Discourse, regardless of whether the page is served to a user (where it is not needed anyway) or to a crawler.

I do this in the container yml file here:

run:
  - exec: echo "Beginning of custom commands"
  - exec: sed -i '/canonical_link_tag/d' /var/www/discourse/app/views/layouts/_head.html.erb
  - exec: echo "End of custom commands"

Confirmed when building the container:

Screen Shot 2020-08-01 at 11.50.50 AM1454×238 103 KB

Further confirmed in the source code that indeed this works as expected and all canonical tags are stripped out of the Discourse pages served to GoogleBot:

Screen Shot 2020-08-01 at 12.02.35 PM853×699 140 KB

Discourse Code Reference:

Note:

• Currently removing Line 14 in the file _head.html.erb above.

OK. I finally stopped using this "lame" yml method of removing the canonical link and wrote a simple Discourse plugin for this task: