feat(inputs.diskio): Allow selecting devices by ID (#11703)

plugins/inputs/diskio/README.md

@@ -10,7 +10,9 @@ The diskio input plugin gathers metrics about disk traffic and timing.
   ## By default, telegraf will gather stats for all devices including
   ## disk partitions.
   ## Setting devices will restrict the stats to the specified devices.
-  # devices = ["sda", "sdb", "vd*"]
+  ## NOTE: Globbing expressions (e.g. asterix) are not supported for
+  ##       disk synonyms like '/dev/disk/by-id'.
+  # devices = ["sda", "sdb", "vd*", "/dev/disk/by-id/nvme-eui.00123deadc0de123"]
   ## Uncomment the following line if you need disk serial numbers.
   # skip_serial_number = false
   #

plugins/inputs/diskio/diskio.go

@@ -57,9 +57,11 @@ func (d *DiskIO) Init() error {
 }
 
 func (d *DiskIO) Gather(acc telegraf.Accumulator) error {
-	devices := []string{}
+	var devices []string
 	if d.deviceFilter == nil {
-		devices = d.Devices
+		for _, dev := range d.Devices {
+			devices = append(devices, resolveName(dev))
+		}
 	}
 
 	diskio, err := d.ps.DiskIO(devices)
@@ -77,6 +79,10 @@ func (d *DiskIO) Gather(acc telegraf.Accumulator) error {
 		var devLinks []string
 		tags["name"], devLinks = d.diskName(io.Name)
 
+		if wwid := getDeviceWWID(io.Name); wwid != "" {
+			tags["wwid"] = wwid
+		}
+
 		if d.deviceFilter != nil && !match {
 			for _, devLink := range devLinks {
 				if d.deviceFilter.Match(devLink) {

plugins/inputs/diskio/diskio_linux.go

@@ -3,8 +3,11 @@ package diskio
 import (
 	"bufio"
 	"bytes"
+	"errors"
 	"fmt"
+	"io/fs"
 	"os"
+	"path/filepath"
 	"strings"
 
 	"golang.org/x/sys/unix"
@@ -105,3 +108,29 @@ func (d *DiskIO) diskInfo(devName string) (map[string]string, error) {
 
 	return di, nil
 }
+
+func resolveName(name string) string {
+	resolved, err := filepath.EvalSymlinks(name)
+	if err == nil {
+		return resolved
+	}
+	if err != nil && !errors.Is(err, fs.ErrNotExist) {
+		return name
+	}
+	// Try to prepend "/dev"
+	resolved, err = filepath.EvalSymlinks(filepath.Join("/dev", name))
+	if err != nil {
+		return name
+	}
+
+	return resolved
+}
+
+func getDeviceWWID(name string) string {
+	path := fmt.Sprintf("/sys/block/%s/wwid", filepath.Base(name))
+	buf, err := os.ReadFile(path)
+	if err != nil {
+		return ""
+	}
+	return strings.TrimSuffix(string(buf), "\n")
+}

plugins/inputs/diskio/diskio_other.go

@@ -7,3 +7,11 @@ type diskInfoCache struct{}
 func (d *DiskIO) diskInfo(devName string) (map[string]string, error) {
 	return nil, nil
 }
+
+func resolveName(name string) string {
+	return name
+}
+
+func getDeviceWWID(name string) string {
+	return ""
+}

plugins/inputs/diskio/sample.conf

@@ -3,7 +3,9 @@
   ## By default, telegraf will gather stats for all devices including
   ## disk partitions.
   ## Setting devices will restrict the stats to the specified devices.
-  # devices = ["sda", "sdb", "vd*"]
+  ## NOTE: Globbing expressions (e.g. asterix) are not supported for
+  ##       disk synonyms like '/dev/disk/by-id'.
+  # devices = ["sda", "sdb", "vd*", "/dev/disk/by-id/nvme-eui.00123deadc0de123"]
   ## Uncomment the following line if you need disk serial numbers.
   # skip_serial_number = false
   #