Hi @s.u,
The Kaltura endpoint/service URL you input during the configuration stage must be resolvable/reachable from within the Kaltura server and all the machines from which you intend to use the web interfaces [Admin Console and KMC].
From your output:
ERROR: Couldn’t make an API request to http://example.com/api_v3/index.php?service=system&action=ping.
It would appear as though it is not.
Also, because of how it works, the same port must be used both internally and externally so:
docker run -d --name=kaltura -p 8080:80
won’t work.