Pantheon Recipe limits Imagemagick & blocks PDF thumbnail generation for Wordpress.

[macronomicus]

It took me a while to figure out what the culprit was borking PDF thumbnails on Pantheon recipe,
eventually I figured out I could run the following
wp media regenerate --debug
Which gave me some good errors & lead me to discover an olde security recommendation thats no longer needed when you have the latest Ghostscript, which the pantheon recipe & containers do already have. So it can be safely changed, now my site is functioning properly on the local pantheon build, but I suspect I might have to change things up on the pantheon server side too when I cross that bridge, these are their containers we're using in Lando right? It should be nearly identical to production environment?

To resolve I did the following, in case its useful to anyone finding this googling.
lando ssh --service appserver --user root --command "apt-get update && apt install nano -y"

then log in as root
lando ssh --service appserver --user root
cd ..
cd etc/ImageMagick-6
nano policy.xml
CHANGE none TO read
old...
<policy domain="coder" rights="none" pattern="PDF" />
new...
<policy domain="coder" rights="read" pattern="PDF" />

Anyhow, it was such a weird one I just thought itd be useful here, nothing much comes up in context when googling the problem, so at least its here now, & perhaps it can be fixed upstream in the pantheon containers, or a better fix than I found is figured out.

[macronomicus]

I checked, it is doing the same thing on the production side up on pantheon, so its just the default state for latest wordpress sites then. So, I need find if there's a place I can add this requirement, maybe in the pantheon.yml or something nice and convenient like that would be nice perhaps, as I dont wish to create a custom upstream for such a tiny change.

Im surprised there's nothing on google about it, but I guess needing to use the inbuilt wordpress feature for pdf thumbnails isnt that popular lol.

[macronomicus]

Updating the site to use PHP 8.2 via pantheon.yml cleared things up for me since the needed change was made in that build, just had to lando rebuild afterwards & it fetched the updated appserver into my local lando dev.

I guess that explains why I found nobody complaining in google lol, I had made the sandbox site for this 2 years ago but just working on it now, so I guess it still had older php even though I did upstream updates. Ooof.