[VOL-3255] enhancement to support device metrics
Change-Id: Ic26c2db30a58943a4eef6276ae1cf40350d51702
diff --git a/vendor/github.com/prometheus/procfs/mountinfo.go b/vendor/github.com/prometheus/procfs/mountinfo.go
new file mode 100644
index 0000000..61fa618
--- /dev/null
+++ b/vendor/github.com/prometheus/procfs/mountinfo.go
@@ -0,0 +1,178 @@
+// Copyright 2019 The Prometheus 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 procfs
+
+import (
+ "bufio"
+ "fmt"
+ "io"
+ "os"
+ "strconv"
+ "strings"
+)
+
+var validOptionalFields = map[string]bool{
+ "shared": true,
+ "master": true,
+ "propagate_from": true,
+ "unbindable": true,
+}
+
+// A MountInfo is a type that describes the details, options
+// for each mount, parsed from /proc/self/mountinfo.
+// The fields described in each entry of /proc/self/mountinfo
+// is described in the following man page.
+// http://man7.org/linux/man-pages/man5/proc.5.html
+type MountInfo struct {
+ // Unique Id for the mount
+ MountId int
+ // The Id of the parent mount
+ ParentId int
+ // The value of `st_dev` for the files on this FS
+ MajorMinorVer string
+ // The pathname of the directory in the FS that forms
+ // the root for this mount
+ Root string
+ // The pathname of the mount point relative to the root
+ MountPoint string
+ // Mount options
+ Options map[string]string
+ // Zero or more optional fields
+ OptionalFields map[string]string
+ // The Filesystem type
+ FSType string
+ // FS specific information or "none"
+ Source string
+ // Superblock options
+ SuperOptions map[string]string
+}
+
+// Returns part of the mountinfo line, if it exists, else an empty string.
+func getStringSliceElement(parts []string, idx int, defaultValue string) string {
+ if idx >= len(parts) {
+ return defaultValue
+ }
+ return parts[idx]
+}
+
+// Reads each line of the mountinfo file, and returns a list of formatted MountInfo structs.
+func parseMountInfo(r io.Reader) ([]*MountInfo, error) {
+ mounts := []*MountInfo{}
+ scanner := bufio.NewScanner(r)
+ for scanner.Scan() {
+ mountString := scanner.Text()
+ parsedMounts, err := parseMountInfoString(mountString)
+ if err != nil {
+ return nil, err
+ }
+ mounts = append(mounts, parsedMounts)
+ }
+
+ err := scanner.Err()
+ return mounts, err
+}
+
+// Parses a mountinfo file line, and converts it to a MountInfo struct.
+// An important check here is to see if the hyphen separator, as if it does not exist,
+// it means that the line is malformed.
+func parseMountInfoString(mountString string) (*MountInfo, error) {
+ var err error
+
+ // OptionalFields can be zero, hence these checks to ensure we do not populate the wrong values in the wrong spots
+ separatorIndex := strings.Index(mountString, "-")
+ if separatorIndex == -1 {
+ return nil, fmt.Errorf("no separator found in mountinfo string: %s", mountString)
+ }
+ beforeFields := strings.Fields(mountString[:separatorIndex])
+ afterFields := strings.Fields(mountString[separatorIndex+1:])
+ if (len(beforeFields) + len(afterFields)) < 7 {
+ return nil, fmt.Errorf("too few fields")
+ }
+
+ mount := &MountInfo{
+ MajorMinorVer: getStringSliceElement(beforeFields, 2, ""),
+ Root: getStringSliceElement(beforeFields, 3, ""),
+ MountPoint: getStringSliceElement(beforeFields, 4, ""),
+ Options: mountOptionsParser(getStringSliceElement(beforeFields, 5, "")),
+ OptionalFields: nil,
+ FSType: getStringSliceElement(afterFields, 0, ""),
+ Source: getStringSliceElement(afterFields, 1, ""),
+ SuperOptions: mountOptionsParser(getStringSliceElement(afterFields, 2, "")),
+ }
+
+ mount.MountId, err = strconv.Atoi(getStringSliceElement(beforeFields, 0, ""))
+ if err != nil {
+ return nil, fmt.Errorf("failed to parse mount ID")
+ }
+ mount.ParentId, err = strconv.Atoi(getStringSliceElement(beforeFields, 1, ""))
+ if err != nil {
+ return nil, fmt.Errorf("failed to parse parent ID")
+ }
+ // Has optional fields, which is a space separated list of values.
+ // Example: shared:2 master:7
+ if len(beforeFields) > 6 {
+ mount.OptionalFields = make(map[string]string)
+ optionalFields := beforeFields[6:]
+ for _, field := range optionalFields {
+ optionSplit := strings.Split(field, ":")
+ target, value := optionSplit[0], ""
+ if len(optionSplit) == 2 {
+ value = optionSplit[1]
+ }
+ // Checks if the 'keys' in the optional fields in the mountinfo line are acceptable.
+ // Allowed 'keys' are shared, master, propagate_from, unbindable.
+ if _, ok := validOptionalFields[target]; ok {
+ mount.OptionalFields[target] = value
+ }
+ }
+ }
+ return mount, nil
+}
+
+// Parses the mount options, superblock options.
+func mountOptionsParser(mountOptions string) map[string]string {
+ opts := make(map[string]string)
+ options := strings.Split(mountOptions, ",")
+ for _, opt := range options {
+ splitOption := strings.Split(opt, "=")
+ if len(splitOption) < 2 {
+ key := splitOption[0]
+ opts[key] = ""
+ } else {
+ key, value := splitOption[0], splitOption[1]
+ opts[key] = value
+ }
+ }
+ return opts
+}
+
+// Retrieves mountinfo information from `/proc/self/mountinfo`.
+func GetMounts() ([]*MountInfo, error) {
+ f, err := os.Open("/proc/self/mountinfo")
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+ return parseMountInfo(f)
+}
+
+// Retrieves mountinfo information from a processes' `/proc/<pid>/mountinfo`.
+func GetProcMounts(pid int) ([]*MountInfo, error) {
+ f, err := os.Open(fmt.Sprintf("/proc/%d/mountinfo", pid))
+ if err != nil {
+ return nil, err
+ }
+ defer f.Close()
+ return parseMountInfo(f)
+}