Toggle /ping to artificially return unhealthy response on SIGTERM during requestAcceptGraceTimeout interval

ping/ping.go

@@ -3,19 +3,38 @@ package ping
 import (
 	"fmt"
 	"net/http"
+	"sync"
 
 	"github.com/containous/mux"
 )
 
-//Handler expose ping routes
+// Handler expose ping routes
 type Handler struct {
-	EntryPoint string `description:"Ping entryPoint" export:"true"`
+	EntryPoint  string `description:"Ping entryPoint" export:"true"`
+	terminating bool
+	lock        sync.RWMutex
+}
+
+// SetTerminating causes the ping endpoint to serve non 200 responses.
+func (g *Handler) SetTerminating() {
+	g.lock.Lock()
+	defer g.lock.Unlock()
+
+	g.terminating = true
 }
 
 // AddRoutes add ping routes on a router
-func (g Handler) AddRoutes(router *mux.Router) {
+func (g *Handler) AddRoutes(router *mux.Router) {
 	router.Methods(http.MethodGet, http.MethodHead).Path("/ping").
 		HandlerFunc(func(response http.ResponseWriter, request *http.Request) {
-			fmt.Fprint(response, "OK")
+			g.lock.RLock()
+			defer g.lock.RUnlock()
+
+			statusCode := http.StatusOK
+			if g.terminating {
+				statusCode = http.StatusServiceUnavailable
+			}
+			response.WriteHeader(statusCode)
+			fmt.Fprint(response, http.StatusText(statusCode))
 		})
 }