Unable to load documents: certificate validation error

I have a problem loading documents into collabora.

I am running the image collabora/code on Docker. The server is starting and I can access the discovery.xml and the admin panel

When I try to open a document I use the following URL for a quick test:

https://<collabora_url>:9980/loleaflet/3ae382d/loleaflet.html?WOPISrc=https://<site_url>/wopi/files/69486

The server prints the following Error message:

wsd-00006-00067 2021-10-01 09:24:51.512218 [ docbroker_003 ] ERR Cannot get file info from WOPI storage uri [https://<site_url>/wopi/files/69486?reuse_cookies=SimpleSAMLSessionID%3D23bf434ec8cba81ad98f35d498798e2e]. Error: Certificate validation error: Unacceptable certificate from <site_url>: application verification failure| wsd/Storage.cpp:647
wsd-00006-00067 2021-10-01 09:24:51.513178 [ docbroker_003 ] ERR loading document exception: Certificate validation error| wsd/DocumentBroker.cpp:1445
wsd-00006-00067 2021-10-01 09:24:51.513220 [ docbroker_003 ] ERR Failed to add session to [/wopi/files/69486] with URI [https://<site_url>/wopi/files/69486?reuse_cookies=SimpleSAMLSessionID%3D23bf434ec8cba81ad98f35d498798e2e]: Certificate validation error| wsd/DocumentBroker.cpp:1407
wsd-00006-00067 2021-10-01 09:24:51.513260 [ docbroker_003 ] ERR Error while loading : Certificate validation error| wsd/LOOLWSD.cpp:3465

While in the browser I get this error:
“Failed to read the document from storage. Please contact your storage server administrator”
image_2021_10_01T10_01_28_355Z

I can not figure out what’s is wrong in my implementation. Can someone give me a hint?

The docker container creates a certificate for itself upon creation, which obviously won’t be trusted. You need to set up a reverse proxy, and specify your valid certificate there.