Add exec command to API

pkg/hypervisor/hypervisor.go

@@ -129,6 +129,7 @@ func (m *Node) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 			}
 			r.Get("/user", m.users.UserInfo())
 			r.Post("/change-password", m.users.ChangePassword())
+			r.Post("/exec", m.exec())
 			r.Get("/nodes", m.getNodes())
 			r.Get("/nodes/{pk}", m.getNode())
 			r.Get("/nodes/{pk}/apps", m.getApps())
@@ -150,6 +151,30 @@ func (m *Node) ServeHTTP(w http.ResponseWriter, req *http.Request) {
 	r.ServeHTTP(w, req)
 }
 
+// executes a command and returns its output
+func (m *Node) exec() http.HandlerFunc {
+	return m.withCtx(m.nodeCtx, func(w http.ResponseWriter, r *http.Request, ctx *httpCtx) {
+		var reqBody struct {
+			Command string `json:"command"`
+		}
+		if err := httputil.ReadJSON(r, &reqBody); err != nil {
+			httputil.WriteJSON(w, r, http.StatusBadRequest, err)
+			return
+		}
+
+		out, err := ctx.RPC.Exec(reqBody.Command)
+		if err != nil {
+			httputil.WriteJSON(w, r, http.StatusInternalServerError, err)
+			return
+		}
+
+		output := struct {
+			Output string `json:"output"`
+		}{string(out)}
+		httputil.WriteJSON(w, r, http.StatusOK, output)
+	})
+}
+
 type summaryResp struct {
 	TCPAddr string `json:"tcp_addr"`
 	*visor.Summary