Instead of blindly waiting long enough for a disruptive change to
have been observed by the old leader and followers, we instead rely
on the approximation that checkOnlyLeaderCanWrite provides - i.e.
only a single actor believes they are the leader. This does not
account for clients that were in the followers list before and after
the disruptive change, but it serves as a reasonable approximation.
Signed-off-by: Monis Khan <mok@vmware.com>
Those images that are pulled from Dockerhub will cause pull failures
on some test clusters due to Dockerhub rate limiting.
Because we already have some images that we use for testing, and
because those images are already pre-loaded onto our CI clusters
to make the tests faster, use one of those images and always specify
PullIfNotPresent to avoid pulling the image again during the integration
test.
OpenShift has good defaults for these duration fields that we can
use instead of coming up with them ourselves:
e14e06ba8d/pkg/config/leaderelection/leaderelection.go (L87-L109)
Copied here for easy future reference:
// We want to be able to tolerate 60s of kube-apiserver disruption without causing pod restarts.
// We want the graceful lease re-acquisition fairly quick to avoid waits on new deployments and other rollouts.
// We want a single set of guidance for nearly every lease in openshift. If you're special, we'll let you know.
// 1. clock skew tolerance is leaseDuration-renewDeadline == 30s
// 2. kube-apiserver downtime tolerance is == 78s
// lastRetry=floor(renewDeadline/retryPeriod)*retryPeriod == 104
// downtimeTolerance = lastRetry-retryPeriod == 78s
// 3. worst non-graceful lease acquisition is leaseDuration+retryPeriod == 163s
// 4. worst graceful lease acquisition is retryPeriod == 26s
if ret.LeaseDuration.Duration == 0 {
ret.LeaseDuration.Duration = 137 * time.Second
}
if ret.RenewDeadline.Duration == 0 {
// this gives 107/26=4 retries and allows for 137-107=30 seconds of clock skew
// if the kube-apiserver is unavailable for 60s starting just before t=26 (the first renew),
// then we will retry on 26s intervals until t=104 (kube-apiserver came back up at 86), and there will
// be 33 seconds of extra time before the lease is lost.
ret.RenewDeadline.Duration = 107 * time.Second
}
if ret.RetryPeriod.Duration == 0 {
ret.RetryPeriod.Duration = 26 * time.Second
}
Signed-off-by: Monis Khan <mok@vmware.com>
This change fixes a small race condition that occurred when the
current leader failed to renew its lease. Before this change, the
leader would first release the lease via the Kube API and then would
update its in-memory status to reflect that change. Now those
events occur in the reverse (i.e. correct) order.
Signed-off-by: Monis Khan <mok@vmware.com>
Even though a client may hold the leader election lock in the Kube
lease API, that does not mean it has had a chance to update its
internal state to reflect that. Thus we retry the checks in
checkOnlyLeaderCanWrite a few times to allow the client to catch up.
Signed-off-by: Monis Khan <mok@vmware.com>
We no longer have a transitive dependency on this older repository, so we don't need the replace directive anymore.
There is a new fork of this that we should move to (https://github.com/golang-jwt/jwt), but we can't easily do that until a couple of our direct dependencies upgrade.
This is a revert of d162cb9adf.
Signed-off-by: Matt Moyer <moyerm@vmware.com>
- Change list of attributeParsingOverrides to a map
- Add unit test for sAMAccountName as group name without the override
- Change some comments in the the type definition.
The Kube API server code that we use will cast inputs in an attempt
to see if they implement optional interfaces. This change adds a
simple wrapper struct to prevent such casts from causing us any
issues.
Signed-off-by: Monis Khan <mok@vmware.com>
