From 920a49c8464b0bbc6552824b1ca6fc144782510c Mon Sep 17 00:00:00 2001
From: Ganga Mahesh Siddem <gangams@microsoft.com>
Date: Mon, 30 Oct 2023 01:12:12 -0700
Subject: [PATCH] fix(input.prometheus): Read bearer token from file every time
 (#14191)

---
 plugins/inputs/prometheus/kubernetes.go | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/plugins/inputs/prometheus/kubernetes.go b/plugins/inputs/prometheus/kubernetes.go
index 866654d8a..ed892c9aa 100644
--- a/plugins/inputs/prometheus/kubernetes.go
+++ b/plugins/inputs/prometheus/kubernetes.go
@@ -8,6 +8,7 @@ import (
 	"net"
 	"net/http"
 	"net/url"
+	"os"
 	"os/user"
 	"path/filepath"
 	"strconv"
@@ -92,7 +93,16 @@ func (p *Prometheus) startK8s(ctx context.Context) error {
 				return
 			case <-time.After(time.Second):
 				if p.isNodeScrapeScope {
-					err = p.cAdvisor(ctx, config.BearerToken)
+					bearerToken := config.BearerToken
+					if config.BearerTokenFile != "" {
+						bearerTokenBytes, err := os.ReadFile(config.BearerTokenFile)
+						if err != nil {
+							p.Log.Errorf("Error reading bearer token file hence falling back to BearerToken: %s", err.Error())
+						} else {
+							bearerToken = string(bearerTokenBytes)
+						}
+					}
+					err = p.cAdvisor(ctx, bearerToken)
 					if err != nil {
 						p.Log.Errorf("Unable to monitor pods with node scrape scope: %s", err.Error())
 					}