Change funtionality so connection header value is empty when keep alive settings are enabled

Author: bjee19

internal/mode/static/nginx/config/servers.go

@@ -727,11 +727,16 @@ func generateProxySetHeaders(
 	um UpstreamMap,
 	backends []dataplane.Backend,
 ) []http.Header {
-	var keepAlive bool
+	modifiedConnectionHeader := connectionHeader
 
 	for _, backend := range backends {
 		if um.keepAliveEnabled(backend.UpstreamName) {
-			keepAlive = true
+			// if keep-alive settings are enabled on any upstream, the connection header value
+			// must be empty for the location
+			modifiedConnectionHeader = http.Header{
+				Name:  connectionHeader.Name,
+				Value: "",
+			}
 			break
 		}
 	}
@@ -741,10 +746,7 @@ func generateProxySetHeaders(
 		extraHeaders = append(extraHeaders, authorityHeader)
 	} else {
 		extraHeaders = append(extraHeaders, upgradeHeader)
-
-		if !keepAlive {
-			extraHeaders = append(extraHeaders, connectionHeader)
-		}
+		extraHeaders = append(extraHeaders, modifiedConnectionHeader)
 	}
 
 	headers := createBaseProxySetHeaders(extraHeaders...)

internal/mode/static/nginx/config/servers_test.go

@@ -2971,8 +2971,11 @@ func TestGenerateProxySetHeaders(t *testing.T) {
 			}, grpcBaseHeaders...),
 		},
 		{
-			msg:             "upstream with keepAlive enabled",
-			expectedHeaders: createBaseProxySetHeaders(upgradeHeader),
+			msg: "upstream with keepAlive enabled",
+			expectedHeaders: append(createBaseProxySetHeaders(upgradeHeader), http.Header{
+				Name:  connectionHeader.Name,
+				Value: "",
+			}),
 			upstreamMap: UpstreamMap{
 				nameToUpstream: map[string]http.Upstream{
 					"upstream": {
@@ -2988,8 +2991,11 @@ func TestGenerateProxySetHeaders(t *testing.T) {
 			},
 		},
 		{
-			msg:             "multiple upstreams with keepAlive enabled",
-			expectedHeaders: createBaseProxySetHeaders(upgradeHeader),
+			msg: "multiple upstreams with keepAlive enabled",
+			expectedHeaders: append(createBaseProxySetHeaders(upgradeHeader), http.Header{
+				Name:  connectionHeader.Name,
+				Value: "",
+			}),
 			upstreamMap: UpstreamMap{
 				nameToUpstream: map[string]http.Upstream{
 					"upstream1": {
@@ -3019,8 +3025,11 @@ func TestGenerateProxySetHeaders(t *testing.T) {
 			},
 		},
 		{
-			msg:             "mix of upstreams with keepAlive enabled and disabled",
-			expectedHeaders: createBaseProxySetHeaders(upgradeHeader),
+			msg: "mix of upstreams with keepAlive enabled and disabled",
+			expectedHeaders: append(createBaseProxySetHeaders(upgradeHeader), http.Header{
+				Name:  connectionHeader.Name,
+				Value: "",
+			}),
 			upstreamMap: UpstreamMap{
 				nameToUpstream: map[string]http.Upstream{
 					"upstream1": {