Add QoS support on node

pkg/util/procfs/doc.go

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+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 procfs implements utility functions relating to the /proc mount.
+package procfs

pkg/util/procfs/example_proc_cgroup

@@ -0,0 +1,10 @@
+11:name=systemd:/user/1000.user/c1.session
+10:hugetlb:/user/1000.user/c1.session
+9:perf_event:/user/1000.user/c1.session
+8:blkio:/user/1000.user/c1.session
+7:freezer:/user/1000.user/c1.session
+6:devices:/user/1000.user/c1.session
+5:memory:/user/1000.user/c1.session
+4:cpuacct:/user/1000.user/c1.session
+3:cpu:/user/1000.user/c1.session
+2:cpuset:/

pkg/util/procfs/procfs.go

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+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 procfs
+
+import (
+	"fmt"
+	"io/ioutil"
+	"path"
+	"strconv"
+	"strings"
+)
+
+type ProcFs struct{}
+
+func NewProcFs() ProcFsInterface {
+	return &ProcFs{}
+}
+
+func containerNameFromProcCgroup(content string) (string, error) {
+	lines := strings.Split(content, "\n")
+	for _, line := range lines {
+		entries := strings.SplitN(line, ":", 3)
+		if len(entries) == 3 && entries[1] == "devices" {
+			return strings.TrimSpace(entries[2]), nil
+		}
+	}
+	return "", fmt.Errorf("could not find devices cgroup location")
+}
+
+// getFullContainerName gets the container name given the root process id of the container.
+// Eg. If the devices cgroup for the container is stored in /sys/fs/cgroup/devices/docker/nginx,
+// return docker/nginx. Assumes that the process is part of exactly one cgroup hierarchy.
+func (pfs *ProcFs) GetFullContainerName(pid int) (string, error) {
+	filePath := path.Join("/proc", strconv.Itoa(pid), "cgroup")
+	content, err := ioutil.ReadFile(filePath)
+	if err != nil {
+		return "", err
+	}
+	return containerNameFromProcCgroup(string(content))
+}

pkg/util/procfs/procfs_fake.go

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+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 procfs
+
+type FakeProcFs struct{}
+
+func NewFakeProcFs() ProcFsInterface {
+	return &FakeProcFs{}
+}
+
+// getFullContainerName gets the container name given the root process id of the container.
+// Eg. If the devices cgroup for the container is stored in /sys/fs/cgroup/devices/docker/nginx,
+// return docker/nginx. Assumes that the process is part of exactly one cgroup hierarchy.
+func (fakePfs *FakeProcFs) GetFullContainerName(pid int) (string, error) {
+	return "", nil
+}

pkg/util/procfs/procfs_interface.go

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+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 procfs
+
+type ProcFsInterface interface {
+	// getFullContainerName gets the container name given the root process id of the container.
+	GetFullContainerName(pid int) (string, error)
+}

pkg/util/procfs/procfs_test.go

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+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+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 procfs
+
+import (
+	"io/ioutil"
+	"testing"
+)
+
+func verifyContainerName(procCgroupText, expectedName string, expectedErr bool, t *testing.T) {
+	name, err := containerNameFromProcCgroup(procCgroupText)
+	if expectedErr && err == nil {
+		t.Errorf("Expected error but did not get error in verifyContainerName")
+		return
+	} else if !expectedErr && err != nil {
+		t.Errorf("Expected no error, but got error %+v in verifyContainerName", err)
+		return
+	} else if expectedErr {
+		return
+	}
+	if name != expectedName {
+		t.Errorf("Expected container name %s but got name %s", expectedName, name)
+	}
+}
+
+func TestContainerNameFromProcCgroup(t *testing.T) {
+	procCgroupValid := "2:devices:docker/kubelet"
+	verifyContainerName(procCgroupValid, "docker/kubelet", false, t)
+
+	procCgroupEmpty := ""
+	verifyContainerName(procCgroupEmpty, "", true, t)
+
+	content, err := ioutil.ReadFile("example_proc_cgroup")
+	if err != nil {
+		t.Errorf("Could not read example /proc cgroup file")
+	}
+	verifyContainerName(string(content), "/user/1000.user/c1.session", false, t)
+
+	procCgroupNoDevice := "2:freezer:docker/kubelet\n5:cpuacct:pkg/kubectl"
+	verifyContainerName(procCgroupNoDevice, "", true, t)
+
+	procCgroupInvalid := "devices:docker/kubelet\ncpuacct:pkg/kubectl"
+	verifyContainerName(procCgroupInvalid, "", true, t)
+}