Updated Watcher to use Bookmark events and restart watch from last observed event

fiaas / k8s

Python client library for the Kubernetes API

https://fiaas.github.io/

Apache License 2.0

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Updated Watcher to use Bookmark events and restart watch from last observed event #94

Closed MichelCarroll closed 2 years ago

MichelCarroll commented 4 years ago

This PR is in response to #70 and #71.

I modified the k8s.watcher module to:

observe Bookmark events without forwarding them to the listener
restart the watch from the last observed event's resource version
remove the old cache logic, which is no longer required since we don't replay watch event history from the beginning
add the ability to start a watch from a particular resource version onwards (through the start_at_resource_version parameter)

Please let me know what you think.

gregjones commented 4 years ago

I think it looks good, thanks for the contribution. I did a bit of testing locally, and then some reading of the API docs, and it seems it's expected that clients handle a "410 Gone" status from the API when sending the resourceVersion constraint in a query, as the server doesn't guarantee to know about old events:

{"type":"ERROR","object":{"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"too old resource version: 1312242788 (1474332294)","reason":"Gone","code":410}}

Catching that error and setting the last_seen_version back to None should work for this. I think it would be more friendly if the library took care of this, rather than leaving it up to clients

mortenlj commented 4 years ago

/sem-approve

mortenlj commented 4 years ago

☝️ Trying to get semaphore to build the PR...

MichelCarroll commented 4 years ago

@gregjones Good point. I'll add handling for the "too old resource version" case.

@mortenlj Indeed, I'll look at Semaphore and make the adjustments you suggested.

I found your "hacktoberfest" tagged issues. I figured this was a good opportunity to learn more about the k8s API, as well as levelling up my Python skills.

mortenlj commented 3 years ago

@MichelCarroll : Any movement on this?