fix exec -d

Signed-off-by: Victor Vieux <vieux@docker.com>

api/handlers.go

@@ -552,6 +552,14 @@ func getEvents(c *context, w http.ResponseWriter, r *http.Request) {
 	c.eventsHandler.Wait(r.RemoteAddr, until)
 }
 
+// POST /exec/{execid:.*}/start
+func postExecStart(c *context, w http.ResponseWriter, r *http.Request) {
+	if r.Header.Get("Connection") == "" {
+		proxyContainer(c, w, r)
+	}
+	proxyHijack(c, w, r)
+}
+
 // POST /containers/{name:.*}/exec
 func postContainersExec(c *context, w http.ResponseWriter, r *http.Request) {
 	name := mux.Vars(r)["name"]

api/primary.go

@@ -71,7 +71,7 @@ var routes = map[string]map[string]handler{
 		"/containers/{name:.*}/attach":  proxyHijack,
 		"/containers/{name:.*}/copy":    proxyContainer,
 		"/containers/{name:.*}/exec":    postContainersExec,
-		"/exec/{execid:.*}/start":       proxyHijack,
+		"/exec/{execid:.*}/start":       postExecStart,
 		"/exec/{execid:.*}/resize":      proxyContainer,
 		"/volumes":                      postVolumes,
 	},

test/integration/api/exec.bats

@@ -12,7 +12,7 @@ function teardown() {
 	swarm_manage
 	docker_swarm create --name test_container busybox sleep 100
 
-	# if container is not running, exec will failed
+	# if container is not running, exec will fail
 	run docker_swarm exec test_container ls
 	[ "$status" -ne 0 ]
 	[[ "$output" == *"is not running"* ]]
@@ -26,3 +26,22 @@ function teardown() {
 	[ "$status" -eq 0 ]
 	[ "$output" == "foobar" ]
 }
+
+@test "docker exec -d" {
+	start_docker_with_busybox 2
+	swarm_manage
+	docker_swarm create --name test_container busybox sleep 100
+
+	# if container is not running, exec will fail
+	run docker_swarm exec -d test_container ls
+	[ "$status" -ne 0 ]
+	[[ "$output" == *"is not running"* ]]
+
+	docker_swarm start test_container
+
+	# make sure container is up and not paused
+	[ -n $(docker_swarm ps -q --filter=name=test_container --filter=status=running) ]
+
+	run docker_swarm exec -d test_container echo foobar
+	[ "$status" -eq 0 ]
+}