build: move e2e dependencies into e2e/go.mod

Several packages are only used while running the e2e suite. These
packages are less important to update, as the they can not influence the
final executable that is part of the Ceph-CSI container-image.

By moving these dependencies out of the main Ceph-CSI go.mod, it is
easier to identify if a reported CVE affects Ceph-CSI, or only the
testing (like most of the Kubernetes CVEs).

Signed-off-by: Niels de Vos <ndevos@ibm.com>

e2e/vendor/k8s.io/kubernetes/pkg/util/oom/doc.go

@@ -0,0 +1,18 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Package oom implements utility functions relating to out of memory management.
+package oom // import "k8s.io/kubernetes/pkg/util/oom"

e2e/vendor/k8s.io/kubernetes/pkg/util/oom/oom.go

@@ -0,0 +1,26 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package oom
+
+// This is a struct instead of an interface to allow injection of process ID listers and
+// applying OOM score in tests.
+// TODO: make this an interface, and inject a mock ioutil struct for testing.
+type OOMAdjuster struct {
+	pidLister                 func(cgroupName string) ([]int, error)
+	ApplyOOMScoreAdj          func(pid int, oomScoreAdj int) error
+	ApplyOOMScoreAdjContainer func(cgroupName string, oomScoreAdj, maxTries int) error
+}

e2e/vendor/k8s.io/kubernetes/pkg/util/oom/oom_fake.go

@@ -0,0 +1,35 @@
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package oom
+
+type FakeOOMAdjuster struct{}
+
+func NewFakeOOMAdjuster() *OOMAdjuster {
+	return &OOMAdjuster{
+		pidLister:                 func(cgroupName string) ([]int, error) { return make([]int, 0), nil },
+		ApplyOOMScoreAdj:          fakeApplyOOMScoreAdj,
+		ApplyOOMScoreAdjContainer: fakeApplyOOMScoreAdjContainer,
+	}
+}
+
+func fakeApplyOOMScoreAdj(pid int, oomScoreAdj int) error {
+	return nil
+}
+
+func fakeApplyOOMScoreAdjContainer(cgroupName string, oomScoreAdj, maxTries int) error {
+	return nil
+}

e2e/vendor/k8s.io/kubernetes/pkg/util/oom/oom_linux.go

@@ -0,0 +1,130 @@
+//go:build linux
+// +build linux
+
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package oom
+
+import (
+	"fmt"
+	"os"
+	"path"
+	"path/filepath"
+	"strconv"
+	"time"
+
+	cmutil "k8s.io/kubernetes/pkg/kubelet/cm/util"
+
+	"k8s.io/klog/v2"
+)
+
+func NewOOMAdjuster() *OOMAdjuster {
+	oomAdjuster := &OOMAdjuster{
+		pidLister:        getPids,
+		ApplyOOMScoreAdj: applyOOMScoreAdj,
+	}
+	oomAdjuster.ApplyOOMScoreAdjContainer = oomAdjuster.applyOOMScoreAdjContainer
+	return oomAdjuster
+}
+
+func getPids(cgroupName string) ([]int, error) {
+	return cmutil.GetPids(filepath.Join("/", cgroupName))
+}
+
+// Writes 'value' to /proc/<pid>/oom_score_adj. PID = 0 means self
+// Returns os.ErrNotExist if the `pid` does not exist.
+func applyOOMScoreAdj(pid int, oomScoreAdj int) error {
+	if pid < 0 {
+		return fmt.Errorf("invalid PID %d specified for oom_score_adj", pid)
+	}
+
+	var pidStr string
+	if pid == 0 {
+		pidStr = "self"
+	} else {
+		pidStr = strconv.Itoa(pid)
+	}
+
+	maxTries := 2
+	oomScoreAdjPath := path.Join("/proc", pidStr, "oom_score_adj")
+	value := strconv.Itoa(oomScoreAdj)
+	klog.V(4).Infof("attempting to set %q to %q", oomScoreAdjPath, value)
+	var err error
+	for i := 0; i < maxTries; i++ {
+		err = os.WriteFile(oomScoreAdjPath, []byte(value), 0700)
+		if err != nil {
+			if os.IsNotExist(err) {
+				klog.V(2).Infof("%q does not exist", oomScoreAdjPath)
+				return os.ErrNotExist
+			}
+
+			klog.V(3).Info(err)
+			time.Sleep(100 * time.Millisecond)
+			continue
+		}
+		return nil
+	}
+	if err != nil {
+		klog.V(2).Infof("failed to set %q to %q: %v", oomScoreAdjPath, value, err)
+	}
+	return err
+}
+
+// Writes 'value' to /proc/<pid>/oom_score_adj for all processes in cgroup cgroupName.
+// Keeps trying to write until the process list of the cgroup stabilizes, or until maxTries tries.
+func (oomAdjuster *OOMAdjuster) applyOOMScoreAdjContainer(cgroupName string, oomScoreAdj, maxTries int) error {
+	adjustedProcessSet := make(map[int]bool)
+	for i := 0; i < maxTries; i++ {
+		continueAdjusting := false
+		pidList, err := oomAdjuster.pidLister(cgroupName)
+		if err != nil {
+			if os.IsNotExist(err) {
+				// Nothing to do since the container doesn't exist anymore.
+				return os.ErrNotExist
+			}
+			continueAdjusting = true
+			klog.V(10).Infof("Error getting process list for cgroup %s: %+v", cgroupName, err)
+		} else if len(pidList) == 0 {
+			klog.V(10).Infof("Pid list is empty")
+			continueAdjusting = true
+		} else {
+			for _, pid := range pidList {
+				if !adjustedProcessSet[pid] {
+					klog.V(10).Infof("pid %d needs to be set", pid)
+					if err = oomAdjuster.ApplyOOMScoreAdj(pid, oomScoreAdj); err == nil {
+						adjustedProcessSet[pid] = true
+					} else if err == os.ErrNotExist {
+						continue
+					} else {
+						klog.V(10).Infof("cannot adjust oom score for pid %d - %v", pid, err)
+						continueAdjusting = true
+					}
+					// Processes can come and go while we try to apply oom score adjust value. So ignore errors here.
+				}
+			}
+		}
+		if !continueAdjusting {
+			return nil
+		}
+		// There's a slight race. A process might have forked just before we write its OOM score adjust.
+		// The fork might copy the parent process's old OOM score, then this function might execute and
+		// update the parent's OOM score, but the forked process id might not be reflected in cgroup.procs
+		// for a short amount of time. So this function might return without changing the forked process's
+		// OOM score. Very unlikely race, so ignoring this for now.
+	}
+	return fmt.Errorf("exceeded maxTries, some processes might not have desired OOM score")
+}

e2e/vendor/k8s.io/kubernetes/pkg/util/oom/oom_unsupported.go

@@ -0,0 +1,41 @@
+//go:build !linux
+// +build !linux
+
+/*
+Copyright 2015 The Kubernetes Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package oom
+
+import (
+	"errors"
+)
+
+var unsupportedErr = errors.New("setting OOM scores is unsupported in this build")
+
+func NewOOMAdjuster() *OOMAdjuster {
+	return &OOMAdjuster{
+		ApplyOOMScoreAdj:          unsupportedApplyOOMScoreAdj,
+		ApplyOOMScoreAdjContainer: unsupportedApplyOOMScoreAdjContainer,
+	}
+}
+
+func unsupportedApplyOOMScoreAdj(pid int, oomScoreAdj int) error {
+	return unsupportedErr
+}
+
+func unsupportedApplyOOMScoreAdjContainer(cgroupName string, oomScoreAdj, maxTries int) error {
+	return unsupportedErr
+}