Allow passing arguments to controls

app/controls.go

@@ -6,6 +6,7 @@ import (
 
 	log "github.com/Sirupsen/logrus"
 	"github.com/gorilla/mux"
+	"github.com/ugorji/go/codec"
 	"golang.org/x/net/context"
 
 	"github.com/weaveworks/scope/common/xfer"
@@ -29,14 +30,26 @@ func RegisterControlRoutes(router *mux.Router, cr ControlRouter) {
 func handleControl(cr ControlRouter) CtxHandlerFunc {
 	return func(ctx context.Context, w http.ResponseWriter, r *http.Request) {
 		var (
-			vars    = mux.Vars(r)
-			probeID = vars["probeID"]
-			nodeID  = vars["nodeID"]
-			control = vars["control"]
+			vars        = mux.Vars(r)
+			probeID     = vars["probeID"]
+			nodeID      = vars["nodeID"]
+			control     = vars["control"]
+			controlArgs map[string]string
 		)
+
+		if r.ContentLength > 0 {
+			err := codec.NewDecoder(r.Body, &codec.JsonHandle{}).Decode(&controlArgs)
+			defer r.Body.Close()
+			if err != nil {
+				respondWith(w, http.StatusBadRequest, err)
+				return
+			}
+		}
+
 		result, err := cr.Handle(ctx, probeID, xfer.Request{
-			NodeID:  nodeID,
-			Control: control,
+			NodeID:      nodeID,
+			Control:     control,
+			ControlArgs: controlArgs,
 		})
 		if err != nil {
 			respondWith(w, http.StatusBadRequest, err.Error())

app/controls_test.go

@@ -57,7 +57,11 @@ func TestControl(t *testing.T) {
 	httpClient := http.Client{
 		Timeout: 1 * time.Second,
 	}
-	resp, err := httpClient.Post(server.URL+"/api/control/foo/nodeid/control", "", nil)
+	resp, err := httpClient.Post(
+		server.URL+"/api/control/foo/nodeid/control",
+		"application/json",
+		strings.NewReader("{}"),
+	)
 	if err != nil {
 		t.Fatal(err)
 	}

common/xfer/controls.go

@@ -11,9 +11,10 @@ var ErrInvalidMessage = fmt.Errorf("Invalid Message")
 
 // Request is the UI -> App -> Probe message type for control RPCs
 type Request struct {
-	AppID   string // filled in by the probe on receiving this request
-	NodeID  string
-	Control string
+	AppID       string // filled in by the probe on receiving this request
+	NodeID      string
+	Control     string
+	ControlArgs map[string]string
 }
 
 // Response is the Probe -> App -> UI message type for the control RPCs.