log the SHA1 of the received payload

README.md

@@ -25,7 +25,7 @@ Web API:
 * `POST /readyz/enable` signals the Kubernetes LB that this instance is ready to receive traffic
 * `POST /readyz/disable` signals the Kubernetes LB to stop sending requests to this instance
 * `GET /panic` crashes the process with exit code 255
-* `POST /echo` echos the posted content
+* `POST /echo` echos the posted content, logs the SHA1 hash of the content
 * `POST /job` long running job, json body: `{"wait":2}` 
 * `POST /backend` forwards the call to the backend service on `http://backend-podinfo:9898/echo`
 

pkg/server/handlers.go

@@ -12,6 +12,8 @@ import (
 	"time"
 	"os"
 	"bytes"
+	"crypto/sha1"
+	"fmt"
 )
 
 func (s *Server) index(w http.ResponseWriter, r *http.Request) {
@@ -49,7 +51,8 @@ func (s *Server) echo(w http.ResponseWriter, r *http.Request) {
 			w.Write([]byte(err.Error()))
 			return
 		}
-		glog.Infof("Payload received from %s: %s", r.RemoteAddr, string(body))
+		sha1 := hash(string(body))
+		glog.Infof("Payload received from %s hash %s", r.RemoteAddr, sha1)
 		w.WriteHeader(http.StatusAccepted)
 		w.Write(body)
 	default:
@@ -184,3 +187,8 @@ func (s *Server) disable(w http.ResponseWriter, r *http.Request) {
 func (s *Server) panic(w http.ResponseWriter, r *http.Request) {
 	glog.Fatal("Kill switch triggered")
 }
+
+func hash(input string) string {
+	h := sha1.New()
+	return fmt.Sprintf("%x", h.Sum([]byte(input)))
+}