I have NextCloud and Collabora office set up in docker containers. I am able to edit documents in Collabora, but NextCloud logs get filled up with lots of errors from richdocuments about connections timing out when connecting to Collabora container.
If I go to the NextCloud docker container and curl Collabora with the same url it returns without any issues:
$ sudo docker exec -it nextcloud-app-1 bash
$ curl https://office.[domain].com/hosting/capabilities
{"convert-to":{"available":true,"endpoint":"/cool/convert-to"},"hasMobileSupport":true,"hasProxyPrefix":false,"hasTemplateSaveAs":false,"hasTemplateSource":true,"hasWASMSupport":false,"hasZoteroSupport":true,"productName":"Collabora Online Development Edition","productVersion":"23.05.9.3","productVersionHash":"11d108b","serverId":"d370b82b"}
The full error message:
ConnectException cURL error 28: Connection timed out after 45000 milliseconds (see libcurl - Error Codes) for https://office.[domain].com/hosting/capabilities
Failed to fetch the Collabora capabilities endpoint: cURL error 28: Connection timed out after 45000 milliseconds (see libcurl - Error Codes) for https://office.[domain].com/hosting/capabilities
P.S. I am assuming that richdocuments app is the same thing as Nextcloud Office in the apps listing. The different names had me confused for a while.