fix: re-init azure monitor http client on context deadline error (#11030)

plugins/outputs/azure_monitor/azure_monitor.go

@@ -3,12 +3,14 @@ package azure_monitor
 import (
 	"bytes"
 	"compress/gzip"
+	"context"
 	"encoding/binary"
 	"encoding/json"
 	"fmt"
 	"hash/fnv"
 	"io"
 	"net/http"
+	"net/url"
 	"regexp"
 	"strings"
 	"time"
@@ -109,12 +111,7 @@ func (a *AzureMonitor) Connect() error {
 		a.Timeout = config.Duration(defaultRequestTimeout)
 	}
 
-	a.client = &http.Client{
-		Transport: &http.Transport{
-			Proxy: http.ProxyFromEnvironment,
-		},
-		Timeout: time.Duration(a.Timeout),
-	}
+	a.initHTTPClient()
 
 	var err error
 	var region string
@@ -168,6 +165,15 @@ func (a *AzureMonitor) Connect() error {
 	return nil
 }
 
+func (a *AzureMonitor) initHTTPClient() {
+	a.client = &http.Client{
+		Transport: &http.Transport{
+			Proxy: http.ProxyFromEnvironment,
+		},
+		Timeout: time.Duration(a.Timeout),
+	}
+}
+
 // vmMetadata retrieves metadata about the current Azure VM
 func vmInstanceMetadata(c *http.Client) (region string, resourceID string, err error) {
 	req, err := http.NewRequest("GET", vmInstanceMetadataURL, nil)
@@ -313,6 +319,10 @@ func (a *AzureMonitor) send(body []byte) error {
 
 	resp, err := a.client.Do(req)
 	if err != nil {
+		if err.(*url.Error).Unwrap() == context.DeadlineExceeded {
+			a.initHTTPClient()
+		}
+
 		return err
 	}
 	defer resp.Body.Close()