Merge pull request #8 from lukaszbudnik/cors-support

added CORS support

README.md

@@ -1,4 +1,4 @@
-# yosoy
+# yosoy ![Go](https://github.com/lukaszbudnik/yosoy/workflows/Go/badge.svg) ![Docker](https://github.com/lukaszbudnik/yosoy/workflows/Docker%20Image%20CI/badge.svg)
 
 yosoy is a HTTP service for stubbing and prototyping distributed applications. It is a service which will introduce itself to the caller and print some useful information about its environment. "Yo soy" in español means "I am".
 
@@ -52,19 +52,19 @@ minikube start
 kubectl apply -f test/deployment.yaml
 # tunnel to it and copy the URL as $URL variable
 minikube service --url camarero
-# call it a few times
-curl $URL
-curl $URL
-curl $URL
-curl $URL
+# simulate some HTTP requests
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
+curl -H "Host: gateway.myapp.com" $URL/camarero/abc
 ```
 
 A sample response looks like this:
 
 ```json
 {
-  "host": "127.0.0.1:53366",
-  "requestUri": "/",
+  "host": "gateway.myapp.com",
+  "requestUri": "/camarero/abc",
   "remoteAddr": "172.17.0.1",
   "counter": 4,
   "headers": {

server.go

@@ -26,7 +26,19 @@ type response struct {
 var counter = 0
 var hostname = os.Getenv("HOSTNAME")
 
+func preflight(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+	w.Header().Set("Access-Control-Allow-Methods", "*")
+	w.Header().Set("Access-Control-Allow-Headers", "*")
+	w.Header().Set("Access-Control-Allow-Credentials", "true")
+	w.Header().Set("Access-Control-Expose-Headers", "*")
+	w.Header().Set("Access-Control-Max-Age", "600")
+	w.WriteHeader(http.StatusOK)
+}
+
 func handler(w http.ResponseWriter, req *http.Request) {
+	w.Header().Set("Access-Control-Allow-Origin", "*")
+
 	showEnvs := os.Getenv("YOSOY_SHOW_ENVS")
 	showFiles := os.Getenv("YOSOY_SHOW_FILES")
 
@@ -80,7 +92,8 @@ func main() {
 	r := mux.NewRouter()
 
 	r.Handle("/favicon.ico", r.NotFoundHandler)
-	r.PathPrefix("/").HandlerFunc(handler)
+	r.PathPrefix("/").HandlerFunc(preflight).Methods(http.MethodOptions)
+	r.PathPrefix("/").HandlerFunc(handler).Methods(http.MethodGet, http.MethodPut, http.MethodPatch, http.MethodPost, http.MethodDelete, http.MethodConnect, http.MethodHead, http.MethodTrace)
 
 	loggingRouter := handlers.CombinedLoggingHandler(os.Stdout, r)
 	proxyRouter := handlers.ProxyHeaders(loggingRouter)

server_test.go

@@ -32,8 +32,12 @@ func TestHandler(t *testing.T) {
 	var response response
 	json.Unmarshal(rr.Body.Bytes(), &response)
 
+	// test response
 	assert.Equal(t, 1, response.Counter)
 	assert.Equal(t, "example.org", response.Host)
 	assert.NotEmpty(t, response.EnvVariables)
 	assert.NotEmpty(t, response.Files[".gitignore"])
+
+	// test cors
+	assert.Contains(t, rr.HeaderMap["Access-Control-Allow-Origin"], "*")
 }