From 6acd550f3b330cd2e71adcdf4cb312a2d6cc8ac4 Mon Sep 17 00:00:00 2001
From: Anton Petruhin <anton.petruhin@gmail.com>
Date: Mon, 27 May 2024 17:36:28 +0400
Subject: [PATCH] metrics: add `system_uuid` label

---
 main.go | 19 +++++++++++++++----
 1 file changed, 15 insertions(+), 4 deletions(-)

diff --git a/main.go b/main.go
index 8de69ca..b8eee98 100644
--- a/main.go
+++ b/main.go
@@ -5,7 +5,6 @@ import (
 	"net/http"
 	_ "net/http/pprof"
 	"os"
-	"path"
 	"runtime"
 	"strings"
 
@@ -14,6 +13,7 @@ import (
 	"github.com/coroot/coroot-node-agent/flags"
 	"github.com/coroot/coroot-node-agent/logs"
 	"github.com/coroot/coroot-node-agent/node"
+	"github.com/coroot/coroot-node-agent/proc"
 	"github.com/coroot/coroot-node-agent/profiling"
 	"github.com/coroot/coroot-node-agent/prom"
 	"github.com/coroot/coroot-node-agent/tracing"
@@ -65,8 +65,8 @@ func uname() (string, string, error) {
 }
 
 func machineID() string {
-	for _, p := range []string{"etc/machine-id", "var/lib/dbus/machine-id", "sys/devices/virtual/dmi/id/product_uuid"} {
-		payload, err := os.ReadFile(path.Join("/proc/1/root", p))
+	for _, p := range []string{"/etc/machine-id", "/var/lib/dbus/machine-id", "/sys/devices/virtual/dmi/id/product_uuid"} {
+		payload, err := os.ReadFile(proc.HostPath(p))
 		if err != nil {
 			klog.Warningln("failed to read machine-id:", err)
 			continue
@@ -78,6 +78,15 @@ func machineID() string {
 	return ""
 }
 
+func systemUUID() string {
+	payload, err := os.ReadFile(proc.HostPath("/sys/devices/virtual/dmi/id/product_uuid"))
+	if err != nil {
+		klog.Warningln("failed to read system-uuid:", err)
+		return ""
+	}
+	return strings.TrimSpace(string(payload))
+}
+
 func whitelistNodeExternalNetworks() {
 	netdevs, err := node.NetDevices()
 	if err != nil {
@@ -119,11 +128,13 @@ func main() {
 	whitelistNodeExternalNetworks()
 
 	machineId := machineID()
+	systemUuid := systemUUID()
+
 	tracing.Init(machineId, hostname, version)
 	logs.Init(machineId, hostname, version)
 
 	registry := prometheus.NewRegistry()
-	registerer := prometheus.WrapRegistererWith(prometheus.Labels{"machine_id": machineId}, registry)
+	registerer := prometheus.WrapRegistererWith(prometheus.Labels{"machine_id": machineId, "system_uuid": systemUuid}, registry)
 
 	registerer.MustRegister(info("node_agent_info", version))