Instead of modifying the PodSchedulingContext and then creating or updating it,
now the required changes (selected node, potential nodes) are tracked and the
actual input for an API call is created if (and only if) needed at the end.
This makes the code easier to read and change. In particular, replacing the
Update call with Patch or Apply is easy.
7a63997c8a added a global variable which gets set multiple times by
different goroutines in integration tests, leading to a data race:
WARNING: DATA RACE
Write at 0x00000a626928 by goroutine 87080:
k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/storage/etcd3/metrics.SetStorageMonitorGetter()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/storage/etcd3/metrics/metrics.go:231 +0x104
k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/server/options.(*EtcdOptions).ApplyWithStorageFactoryTo()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/server/options/etcd.go:242 +0xbd
k8s.io/kubernetes/pkg/controlplane/apiserver.BuildGenericConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controlplane/apiserver/config.go:124 +0x1c3d
k8s.io/kubernetes/cmd/kube-apiserver/app.CreateKubeAPIServerConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/server.go:218 +0xeb
k8s.io/kubernetes/cmd/kube-apiserver/app.NewConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/config.go:74 +0xd5
k8s.io/kubernetes/cmd/kube-apiserver/app/testing.StartTestServer()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/testing/testserver.go:299 +0x2e97
k8s.io/kubernetes/cmd/kube-apiserver/app/testing.StartTestServerOrDie()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/testing/testserver.go:423 +0xb2
k8s.io/kubernetes/test/integration/controlplane.testReconcilersAPIServerLease.func3()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/test/integration/controlplane/kube_apiserver_test.go:486 +0x1dd
k8s.io/kubernetes/test/integration/controlplane.testReconcilersAPIServerLease.func7()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/test/integration/controlplane/kube_apiserver_test.go:488 +0x47
Previous write at 0x00000a626928 by goroutine 87079:
k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/storage/etcd3/metrics.SetStorageMonitorGetter()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/storage/etcd3/metrics/metrics.go:231 +0x104
k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/server/options.(*EtcdOptions).ApplyWithStorageFactoryTo()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/vendor/k8s.io/apiserver/pkg/server/options/etcd.go:242 +0xbd
k8s.io/kubernetes/pkg/controlplane/apiserver.BuildGenericConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/pkg/controlplane/apiserver/config.go:124 +0x1c3d
k8s.io/kubernetes/cmd/kube-apiserver/app.CreateKubeAPIServerConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/server.go:218 +0xeb
k8s.io/kubernetes/cmd/kube-apiserver/app.NewConfig()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/config.go:74 +0xd5
k8s.io/kubernetes/cmd/kube-apiserver/app/testing.StartTestServer()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/testing/testserver.go:299 +0x2e97
k8s.io/kubernetes/cmd/kube-apiserver/app/testing.StartTestServerOrDie()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/cmd/kube-apiserver/app/testing/testserver.go:423 +0xb2
k8s.io/kubernetes/test/integration/controlplane.testReconcilersAPIServerLease.func3()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/test/integration/controlplane/kube_apiserver_test.go:486 +0x1dd
k8s.io/kubernetes/test/integration/controlplane.testReconcilersAPIServerLease.func7()
/home/prow/go/src/k8s.io/kubernetes/_output/local/go/src/k8s.io/kubernetes/test/integration/controlplane/kube_apiserver_test.go:488 +0x47
Mutex locking avoids the data race. Whether this variable really can be used
safely by those concurrent (?) tests is a different question...
// AnnotateInitialEventsEndBookmark adds a special annotation to the given object
// which indicates that the initial events have been sent.
//
// Note that this function assumes that the obj's annotation
// field is a reference type (i.e. a map).
