[ upstream commit ba9031b ]

The controller functions could potentially block forever while waiting
on channels to close. Bind waiting on the channel and check of the etcd
version to the controller and etcd client context so these operations
get cancelled.

MERGE CONFLICT:
Due to not passing the etcd client context to the controller, the etcd client
context is an exit case as well.

Signed-off-by: Thomas Graf <thomas@cilium.io>

[ upstream commit f6a751f ]

Same as ba9031b ("etcd: Ensure that session renewal controller exit") but
for the lock session.

MERGE CONFLICT: Due to not providing the etcd client context to the controller,
the etcd client controller must be checked as well in the select conditionals.

Signed-off-by: Thomas Graf <thomas@cilium.io>

[ upstream commit 02a1810 ]

Signed-off-by: Thomas Graf <thomas@cilium.io>

[ upstream commit 0262854 ]

The context passed into NewSession() was supposed to enforce a timeout on the
NewSession() operation which is triggering a Grant() and KeepAlive()
instruction. However, the context passed into NewSession() will also be
associated with the resulting lease. As per etcd documentation, this will
result in:

> If the context is canceled before Close() completes, the session's lease will
> be abandoned and left to expire instead of being revoked.

Because of this, any session renewal triggering a new session would create a
session that is immediately closed again due to the context passed into
NewSession being cancelled when the controller run ends successfully. This
resulted in any renewed session to have an effective lifetime of 10
milliseconds before requiring renewal again.

Fixes: #12619
Fixes: 8524fca ("kvstore: Add session renew backoff")

Signed-off-by: Thomas Graf <thomas@cilium.io>