As we understood it, Kopf lets you build an entire operator in Python, with the watch/update/cache/expansion logic all implemented in Python. But the first operator we wrote in it just didn't feel right. We had to talk to the K8S API from Python to do all the expansions. It was too complex. We also had aesthetic issues with the Kopf API.
Metacontroller gave us a small, Go binary which takes care of all the complex parts (watch/update/cache). Having to write only the expansion part in Python felt like a great simplification - especially now that we have Pydantic.
As we understood it, Kopf lets you build an entire operator in Python, with the watch/update/cache/expansion logic all implemented in Python. But the first operator we wrote in it just didn't feel right. We had to talk to the K8S API from Python to do all the expansions. It was too complex. We also had aesthetic issues with the Kopf API.
Metacontroller gave us a small, Go binary which takes care of all the complex parts (watch/update/cache). Having to write only the expansion part in Python felt like a great simplification - especially now that we have Pydantic.