Set the Via header in proxy requests to origin and in client responses (

air-verse#629)

* Set the Via header in proxy requests to origin and in client responses

* Remove pseudonym and use host only

runner/proxy.go

@@ -101,6 +101,10 @@ func (p *Proxy) proxyHandler(w http.ResponseWriter, r *http.Request) {
 	}
 	req.Header.Set("X-Forwarded-For", r.RemoteAddr)
 
+	// set the via header
+	viaHeaderValue := fmt.Sprintf("%s %s", r.Proto, r.Host)
+	req.Header.Set("Via", viaHeaderValue)
+
 	// air will restart the server. it may take a few milliseconds for it to start back up.
 	// therefore, we retry until the server becomes available or this retry loop exits with an error.
 	var resp *http.Response
@@ -127,6 +131,7 @@ func (p *Proxy) proxyHandler(w http.ResponseWriter, r *http.Request) {
 			w.Header().Add(k, v)
 		}
 	}
+	w.Header().Add("Via", viaHeaderValue)
 	w.WriteHeader(resp.StatusCode)
 
 	if !strings.Contains(resp.Header.Get("Content-Type"), "text/html") {

runner/proxy_test.go

@@ -129,6 +129,16 @@ func TestProxy_proxyHandler(t *testing.T) {
 				assert.Equal(t, r.Foo, "bar")
 			},
 		},
+		{
+			name: "set_via_header",
+			req: func() *http.Request {
+				req := httptest.NewRequest("GET", fmt.Sprintf("http://localhost:%d", proxyPort), nil)
+				return req
+			},
+			assert: func(resp *http.Request) {
+				assert.Equal(t, fmt.Sprintf("HTTP/1.1 localhost:%d", proxyPort), resp.Header.Get("Via"))
+			},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {