Does anybody know why and when thumbnails for YouTube videos are shown or not? It appears to depend on the lemmy instance the posts are served from:
Without Thumbnails
With Thumbnails
Update: It’s not only YT thumbnails which aren’t shown. This is your post about the free 24 slot bag as shown on lemmy.wtf (without thumbnail), lemmy.world (without thumbnail) and feddit.de (with thumbnail):
I also found this
https://github.com/LemmyNet/lemmy-ui/issues/20
There is an environment variable
LEMMY_UI_DISABLE_CSP(default : false) to configurelemmy-ui. Do you set this on your instance or do you set aContent-Security-PolicxyHeader somewhere in your webserver/nginx config?I just use the settings as it is shown in the installation guide for Docker: https://join-lemmy.org/docs/en/administration/install_docker.html
OK. Looks like the CSP headers are the same on working and not working instances.
What I found surprising is that chrome loads the thumbnail without accessing the actual YT URL (contrary to what I expected) from the “pictrs” server of the instance serving the post. Which means that the thumbnail gets only extracted once and is then stored along with the post.
Brainstorming
iframely➡ https://github.com/LemmyNet/lemmy/pull/1706fetch_site_metadata➡ https://github.com/LemmyNet/lemmy/blob/main/crates/api_common/src/request.rsog:*) meta tags from a linked HTML document whenever a post is created or updatedlemmy.wtfnorlemmy.worldbut work onfeddit.defeddit.deextract the missing thumbnail when creating/updating the post? ➡ Yes, I think solemmy.worlddoes not use cloudflare (I think) but they are also (likelemmy.wtf) using docker (I think)Also Not Working on
lemmy.worldBut does on
feddit.deIt’s not only YT thumbnails which aren’t shown. This is your post about the free 24 slot bag as shown on
lemmy.wtf(no thumbnail),lemmy.world(no thumbnail) andfeddit.de(with thumbnail):