Add /ip, /headers, and /user-agent handlers

helpers.go

@@ -2,8 +2,6 @@ package main
 
 import (
 	"encoding/json"
-	"log"
-
 	"net/http"
 	"net/url"
 )
@@ -50,11 +48,7 @@ func getURL(r *http.Request) string {
 func writeResponse(w http.ResponseWriter, r *http.Request, resp *Resp) {
 	resp.Origin = getOrigin(r)
 	resp.URL = getURL(r)
-
-	body, err := json.Marshal(resp)
-	if err != nil {
-		log.Printf("error marshalling %v as JSON: %s", resp, err)
-	}
+	body, _ := json.Marshal(resp)
 	writeJSON(w, body)
 }
 

main.go

 package main
 
 import (
+	"encoding/json"
 	"fmt"
 	"html/template"
 	"log"
@@ -21,6 +22,21 @@ type Resp struct {
 	JSON  map[string][]string `json:"json,omitempty"`
 }
 
+// IPResp is the response for the /ip endpoint
+type IPResp struct {
+	Origin string `json:"origin"`
+}
+
+// HeadersResp is the response for the /headers endpoint
+type HeadersResp struct {
+	Headers http.Header `json:"headers"`
+}
+
+// UserAgentResp is the response for the /user-agent endpoint
+type UserAgentResp struct {
+	UserAgent string `json:"user-agent"`
+}
+
 func index(w http.ResponseWriter, r *http.Request) {
 	t, err := template.ParseGlob("templates/*.html")
 	if err != nil {
@@ -44,10 +60,34 @@ func get(w http.ResponseWriter, r *http.Request) {
 	writeResponse(w, r, resp)
 }
 
+func ip(w http.ResponseWriter, r *http.Request) {
+	body, _ := json.Marshal(&IPResp{
+		Origin: getOrigin(r),
+	})
+	writeJSON(w, body)
+}
+
+func userAgent(w http.ResponseWriter, r *http.Request) {
+	body, _ := json.Marshal(&UserAgentResp{
+		UserAgent: r.Header.Get("User-Agent"),
+	})
+	writeJSON(w, body)
+}
+
+func headers(w http.ResponseWriter, r *http.Request) {
+	body, _ := json.Marshal(&HeadersResp{
+		Headers: r.Header,
+	})
+	writeJSON(w, body)
+}
+
 func app() http.Handler {
 	h := http.NewServeMux()
 	h.HandleFunc("/", index)
 	h.HandleFunc("/get", get)
+	h.HandleFunc("/ip", ip)
+	h.HandleFunc("/user-agent", userAgent)
+	h.HandleFunc("/headers", headers)
 	return logger(cors(h))
 }
 

main_test.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
+	"reflect"
 	"strings"
 	"testing"
 )
@@ -148,3 +149,63 @@ func TestGet__XForwardedProto(t *testing.T) {
 		}
 	}
 }
+
+func TestIP(t *testing.T) {
+	r, _ := http.NewRequest("GET", "/ip", nil)
+	r.RemoteAddr = "192.168.0.100"
+	w := httptest.NewRecorder()
+	app().ServeHTTP(w, r)
+
+	var resp *IPResp
+	err := json.Unmarshal(w.Body.Bytes(), &resp)
+	if err != nil {
+		t.Fatalf("failed to unmarshal body %s from JSON: %s", w.Body, err)
+	}
+
+	if resp.Origin != r.RemoteAddr {
+		t.Fatalf("%#v != %#v", resp.Origin, r.RemoteAddr)
+	}
+}
+
+func TestUserAgent(t *testing.T) {
+	r, _ := http.NewRequest("GET", "/user-agent", nil)
+	r.Header.Set("User-Agent", "test")
+	w := httptest.NewRecorder()
+	app().ServeHTTP(w, r)
+
+	var resp *UserAgentResp
+	err := json.Unmarshal(w.Body.Bytes(), &resp)
+	if err != nil {
+		t.Fatalf("failed to unmarshal body %s from JSON: %s", w.Body, err)
+	}
+
+	if resp.UserAgent != "test" {
+		t.Fatalf("%#v != \"test\"", resp.UserAgent)
+	}
+}
+
+func TestHeaders(t *testing.T) {
+	r, _ := http.NewRequest("GET", "/headers", nil)
+	r.Header.Set("User-Agent", "test")
+	r.Header.Set("Foo-Header", "foo")
+	r.Header.Add("Bar-Header", "bar1")
+	r.Header.Add("Bar-Header", "bar2")
+	w := httptest.NewRecorder()
+	app().ServeHTTP(w, r)
+
+	var resp *HeadersResp
+	err := json.Unmarshal(w.Body.Bytes(), &resp)
+	if err != nil {
+		t.Fatalf("failed to unmarshal body %s from JSON: %s", w.Body, err)
+	}
+
+	for k, expectedValues := range r.Header {
+		values, ok := resp.Headers[http.CanonicalHeaderKey(k)]
+		if !ok {
+			t.Fatalf("expected header %#v in response", k)
+		}
+		if !reflect.DeepEqual(expectedValues, values) {
+			t.Fatalf("%#v != %#v", values, expectedValues)
+		}
+	}
+}