问题
When you click on linkedin sharing button. The summary displays title, description from open graph metadatas, but the picture is missing.
Here is an example : https://viuz.com/2016/09/15/recrute-par-un-algorithme-et-7-autres-pepites-digitales/
回答1:
LinkedInBot/1.0 fails to make a handshake with your server and that's why it can't connect to grab page's Open Graph content or image.
You probably won't find LinkedInBot/1.0 requests in your access log. Then you need to allow HTTP access for LinkedInBot/1.0 (and provide http url for image in OG and access over HTTP to images).
LinkedInBot/1.0 uses Jakarta Commons-HttpClient/3.1 which outdated and not supported for a long time. I'm assuming it fails to access most of HTTPS websites with key sizes >= 2048 bits.
I hope devs from LinkedIn are going to fix this issue soon.
回答2:
I finaly find out what was going bad thanks to the po.st team. One of my wordpress plugin was blocking the user agent containing the word jakarta thru the htaccess file. And the linkedin bot name is "LinkedInBot/1.0 (compatible; Mozilla/5.0; Jakarta Commons-HttpClient/3.1 +http://www.linkedin.com)" so everytime I try to crawl the website using that user agent T had a 403 Error use the http://www.botsimulator.com/ to test if you have a similar problem
来源：https://stackoverflow.com/questions/39547457/linkedin-posts-picture-doesnt-appear-in-summary