The previous approach with grabbing via a nginx proxy had some
drawbacks:
- it did not work when the pods only listened on localhost (as
configured by kubeadm) and the proxy got deployed on a different
node
- starting the proxy raced with starting the pods, causing
sporadic test failures because the proxy was not set up
properly unless it saw all pods when starting the e2e.test
- the proxy was always started, whether it is needed or not
- the proxy was left running after a test and then the next
test run triggered potentially confusing messages when
it failed to create objects for the proxy
The new approach is similar to "kubectl port-forward" + "kubectl get
--raw". It uses the port forwarding feature to establish a TCP
connection via a custom dialer, then lets client-go handle TLS and
credentials.
Somehow verifying the server certificate did not work. As this
shouldn't be a big concern for E2E testing, certificate checking gets
disabled on the client side instead of investigating this further.