In the documentation of IBM Cloud Functions, there is mentioned that the functions can be triggered with custom triggers: https://cloud.ibm.com/docs/openwhisk?topic=cloud-functions-feeds_custom
This may be done via: - WebHooks - Polling - Connections
What I have not been able to figure out from the docs: Are Connections and Polling only possible inside of the IBM Cloud ecosystem or generally usable with any service in any platform (e.g. a self-hosted database service)?