Close HTTP2 connections on timeout in influxdb outputs (#7517)

internal/http.go

@@ -4,6 +4,7 @@ import (
 	"crypto/subtle"
 	"net"
 	"net/http"
+	"net/url"
 )
 
 type BasicAuthErrorFunc func(rw http.ResponseWriter)
@@ -95,3 +96,13 @@ func (h *ipRangeHandler) ServeHTTP(rw http.ResponseWriter, req *http.Request) {
 
 	h.onError(rw, http.StatusForbidden)
 }
+
+func OnClientError(client *http.Client, err error) {
+	// Close connection after a timeout error. If this is a HTTP2
+	// connection this ensures that next interval a new connection will be
+	// used and name lookup will be performed.
+	//   https://github.com/golang/go/issues/36026
+	if err, ok := err.(*url.Error); ok && err.Timeout() {
+		client.CloseIdleConnections()
+	}
+}

internal/http_go1.11.go

@@ -1,15 +0,0 @@
-// +build !go1.12
-
-package internal
-
-import "net/http"
-
-func CloseIdleConnections(c *http.Client) {
-	type closeIdler interface {
-		CloseIdleConnections()
-	}
-
-	if tr, ok := c.Transport.(closeIdler); ok {
-		tr.CloseIdleConnections()
-	}
-}

internal/http_go1.12.go

@@ -1,9 +0,0 @@
-// +build go1.12
-
-package internal
-
-import "net/http"
-
-func CloseIdleConnections(c *http.Client) {
-	c.CloseIdleConnections()
-}