adding method to return the hostname where httpbin is running

httpbin/handlers.go

@@ -126,6 +126,14 @@ func (h *HTTPBin) IP(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, body, http.StatusOK)
 }
 
+// Hostname returns the name of the host this program is running on
+func (h *HTTPBin) Hostname(w http.ResponseWriter, r *http.Request) {
+	body, _ := json.Marshal(&hostnameResponse{
+		Hostname: h.HostnameStr,
+	})
+	writeJSON(w, body, http.StatusOK)
+}
+
 // UserAgent echoes the incoming User-Agent header
 func (h *HTTPBin) UserAgent(w http.ResponseWriter, r *http.Request) {
 	body, _ := json.Marshal(&userAgentResponse{

httpbin/handlers_test.go

@@ -375,6 +375,24 @@ func TestIP(t *testing.T) {
 	}
 }
 
+func TestHostname(t *testing.T) {
+	// this cannot be really tested, except to verify that the call returns some hostname and not a HTTP error
+	r, _ := http.NewRequest("GET", "/hostname", nil)
+	w := httptest.NewRecorder()
+	handler.ServeHTTP(w, r)
+	assertStatusCode(t, w, http.StatusOK)
+
+	var resp *hostnameResponse
+	err := json.Unmarshal(w.Body.Bytes(), &resp)
+	if err != nil {
+		t.Fatalf("failed to unmarshal body %s from JSON: %s", w.Body, err)
+	}
+
+	if len(resp.Hostname) == 0 {
+		t.Fatalf("expected non-empty hostname: %q", resp.Hostname)
+	}
+}
+
 func TestUserAgent(t *testing.T) {
 	r, _ := http.NewRequest("GET", "/user-agent", nil)
 	r.Header.Set("User-Agent", "test")

httpbin/httpbin.go

@@ -3,6 +3,7 @@ package httpbin
 import (
 	"net/http"
 	"net/url"
+	"os"
 	"time"
 )
 
@@ -23,6 +24,10 @@ type ipResponse struct {
 	Origin string `json:"origin"`
 }
 
+type hostnameResponse struct {
+	Hostname string `json:"hostname"`
+}
+
 type userAgentResponse struct {
 	UserAgent string `json:"user-agent"`
 }
@@ -99,6 +104,9 @@ type HTTPBin struct {
 
 	// Default parameter values
 	DefaultParams DefaultParams
+
+	// Name of the host we are running on
+	HostnameStr string
 }
 
 // DefaultParams defines default parameter values
@@ -132,6 +140,7 @@ func (h *HTTPBin) Handler() http.Handler {
 	mux.HandleFunc("/put", methods(h.RequestWithBody, "PUT"))
 
 	mux.HandleFunc("/ip", h.IP)
+	mux.HandleFunc("/hostname", h.Hostname)
 	mux.HandleFunc("/user-agent", h.UserAgent)
 	mux.HandleFunc("/headers", h.Headers)
 	mux.HandleFunc("/response-headers", h.ResponseHeaders)
@@ -224,6 +233,12 @@ func New(opts ...OptionFunc) *HTTPBin {
 	for _, opt := range opts {
 		opt(h)
 	}
+	// set the hostname string in the struct
+	hostname, err := os.Hostname()
+	if err != nil {
+		hostname = "unknown"
+	}
+	h.HostnameStr = hostname
 	return h
 }