Add QoS support on node

pkg/util/procfs/procfs.go

@@ -0,0 +1,54 @@
+/*
+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))
+}