Sync port forward context managed hangs on exit for around a minute

[jacobtomlinson]

Which project are you reporting a bug for?

kr8s

What happened?

While investigating #569 I noticed a hang locally when running a sync port forward context manager. It seems to take a long time to exit the context manager.

# Create web server Pod
kubectl run webserver --image nginx --port 80
kubectl expose po webserver

import kr8s
import requests
import time

[svc] = kr8s.get("svc", "webserver")
start = time.time()
with svc.portforward(remote_port=80, local_port="auto") as local_port:
    print(f"After enter: {time.time() - start:.1}s")
    resp = requests.get(f"http://localhost:{local_port}/")
    print(f"After rerquest: {time.time() - start:.1}s")
print(f"After exit: {time.time() - start:.1}s")

After enter: 0.001s
After rerquest: 0.04s
After exit: 70s

# Clean up
kubectl delete svc/webserver po/webserver

Anything else?

No response

[jacobtomlinson]

This does not happen in the asyncio implementation.

In [2]: import kr8s
   ...: import httpx
   ...: import time
   ...: 
   ...: [svc] = [s async for s in kr8s.asyncio.get("svc", "webserver")]
   ...: start = time.time()
   ...: async with svc.portforward(remote_port=80, local_port="auto") as local_port, httpx.AsyncClient() as client:
   ...:     print(f"After enter: {time.time() - start:.1}s")
   ...:     resp = await client.get(f"http://localhost:{local_port}/")
   ...:     print(f"After rerquest: {time.time() - start:.1}s")
   ...: print(f"After exit: {time.time() - start:.1}s")
After enter: 0.01s
After rerquest: 0.05s
After exit: 0.05s