Netlify Alert Insecure mixed content detected

I kept getting these annoying alerts from Netlify on each deploy of my website due to mixing http content with my site that is on https.

The logs on the netlify side looked like the following, but with many more:

9:09:51 PM: Mixed content detected in: /2005/blender-3d-project-orange/index.html
9:09:51 PM: --> insecure img urls:
9:09:51 PM:   - http://blender3d.org/cms/typo3temp/pics/b03fb21cf2.jpg
9:09:54 PM: Mixed content detected in: /2006/rad-mobile/index.html
9:09:54 PM: --> insecure img urls:
9:09:54 PM:   - http://static.flickr.com/81/230155799_4615e0dc84.jpg?v=0
9:09:54 PM: Mixed content detected in: /2006/the-disney-and-pixar-merger/index.html
9:09:54 PM: --> insecure img urls:
9:09:54 PM:   - http://upload.wikimedia.org/wikipedia/en/5/5e/Pixar.jpg
9:09:54 PM: Mixed content detected in: /2006/ubuntu-dapper-drake/index.html
9:09:54 PM: --> insecure img urls:
9:09:54 PM:   - http://photos1.blogger.com/blogger/3110/487/400/Screenshot.png
9:09:55 PM: Mixed content detected in: /2006/xgl-compiz/index.html
9:09:55 PM: --> insecure img urls:
9:09:55 PM:   - http://files.opensuse.org/opensuse/en/thumb/c/cb/Movie-cube.jpg/350px-Movie-cube.jpg
9:09:55 PM: Mixed content detected in: /2007/cups-error-w2-invalid-pers/index.html

Cause

The cause was links to old images that may or may not still work, but are referenced over http instead of https.

Solution

Download the log file from Netlify, or copy and paste it into a text file.

Because getting some images is better than nothing, I created a script from the URL’s in the log to download any images that still exist into a folder, and create a text file that has a list of these images. I can’t find the script I used on this, but if I do, I’ll update the post.

Run this fancy (not fancy) script against the text file, which will modify the broken hyperlinks if an image exists.

#!/bin/bash
input="/tmp/realImages.txt"
while IFS= read -r line
do
  bob=$(basename $line)
  find . -type f -exec sed -i '' -e "s,$line,/images/old/$bob,g" {} \;
done < "$input"