server: a simple http server that serves the HUD view (#877)

internal/cli/up.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"log"
+	"net/http"
 	"time"
 
 	"github.com/fatih/color"
@@ -29,6 +30,7 @@ type upCmd struct {
 	traceTags   string
 	hud         bool
 	autoDeploy  bool
+	port        int
 }
 
 func (c *upCmd) register() *cobra.Command {
@@ -47,6 +49,7 @@ func (c *upCmd) register() *cobra.Command {
 	cmd.Flags().BoolVar(&c.hud, "hud", true, "If true, tilt will open in HUD mode.")
 	cmd.Flags().BoolVar(&c.autoDeploy, "auto-deploy", true, "If false, tilt will wait on <spacebar> to trigger builds")
 	cmd.Flags().BoolVar(&logActionsFlag, "logactions", false, "log all actions and state changes")
+	cmd.Flags().IntVar(&c.port, "port", 0, "Port for the Tilt HTTP server")
 	cmd.Flags().Lookup("logactions").Hidden = true
 	err := cmd.Flags().MarkHidden("image-tag-prefix")
 	if err != nil {
@@ -76,12 +79,14 @@ func (c *upCmd) run(ctx context.Context, args []string) error {
 		span.SetTag(k, v)
 	}
 
-	uh, err := wireHudAndUpper(ctx)
+	threads, err := wireThreads(ctx)
 	if err != nil {
 		return err
 	}
 
-	upper, h := uh.upper, uh.hud
+	upper := threads.upper
+	h := threads.hud
+	server := threads.server
 
 	l := engine.NewLogActionLogger(ctx, upper.Dispatch)
 	ctx = logger.WithLogger(ctx, l)
@@ -108,6 +113,27 @@ func (c *upCmd) run(ctx context.Context, args []string) error {
 		})
 	}
 
+	if c.port != 0 {
+		http.Handle("/", server.Router())
+		httpServer := &http.Server{
+			Addr:    fmt.Sprintf(":%d", c.port),
+			Handler: http.DefaultServeMux,
+		}
+
+		g.Go(func() error {
+			<-ctx.Done()
+			return httpServer.Shutdown(context.Background())
+		})
+
+		g.Go(func() error {
+			err := httpServer.ListenAndServe()
+			if err != nil && err != http.ErrServerClosed {
+				return err
+			}
+			return nil
+		})
+	}
+
 	triggerMode := model.TriggerAuto
 	if !c.autoDeploy {
 		triggerMode = model.TriggerManual

internal/cli/wire.go

@@ -14,6 +14,7 @@ import (
 	"github.com/windmilleng/tilt/internal/dockercompose"
 	"github.com/windmilleng/tilt/internal/engine"
 	"github.com/windmilleng/tilt/internal/hud"
+	"github.com/windmilleng/tilt/internal/hud/server"
 	"github.com/windmilleng/tilt/internal/k8s"
 	"github.com/windmilleng/tilt/internal/store"
 )
@@ -55,6 +56,7 @@ var BaseWireSet = wire.NewSet(
 
 	provideLogActions,
 	store.NewStore,
+	wire.Bind(new(store.RStore), new(store.Store)),
 
 	engine.NewUpper,
 	provideAnalytics,
@@ -63,26 +65,29 @@ var BaseWireSet = wire.NewSet(
 	engine.ProvideFsWatcherMaker,
 	engine.ProvideTimerMaker,
 
-	provideHudAndUpper,
+	server.ProvideHeadsUpServer,
+
+	provideThreads,
 )
 
 func wireDemo(ctx context.Context, branch demo.RepoBranch) (demo.Script, error) {
 	wire.Build(BaseWireSet, demo.NewScript)
 	return demo.Script{}, nil
 }
 
-func wireHudAndUpper(ctx context.Context) (HudAndUpper, error) {
+func wireThreads(ctx context.Context) (Threads, error) {
 	wire.Build(BaseWireSet)
-	return HudAndUpper{}, nil
+	return Threads{}, nil
 }
 
-type HudAndUpper struct {
-	hud   hud.HeadsUpDisplay
-	upper engine.Upper
+type Threads struct {
+	hud    hud.HeadsUpDisplay
+	upper  engine.Upper
+	server server.HeadsUpServer
 }
 
-func provideHudAndUpper(h hud.HeadsUpDisplay, upper engine.Upper) HudAndUpper {
-	return HudAndUpper{h, upper}
+func provideThreads(h hud.HeadsUpDisplay, upper engine.Upper, server server.HeadsUpServer) Threads {
+	return Threads{h, upper, server}
 }
 
 func wireK8sClient(ctx context.Context) (k8s.Client, error) {

internal/hud/server/server.go

@@ -0,0 +1,43 @@
+package server
+
+import (
+	"encoding/json"
+	"fmt"
+	"net/http"
+
+	"github.com/gorilla/mux"
+	"github.com/windmilleng/tilt/internal/store"
+)
+
+type HeadsUpServer struct {
+	store  store.RStore
+	router *mux.Router
+}
+
+func ProvideHeadsUpServer(store store.RStore) HeadsUpServer {
+	r := mux.NewRouter().UseEncodedPath()
+	s := HeadsUpServer{
+		store:  store,
+		router: r,
+	}
+
+	r.HandleFunc("/api/view", s.ViewJSON)
+
+	return s
+}
+
+func (s HeadsUpServer) Router() http.Handler {
+	return s.router
+}
+
+func (s HeadsUpServer) ViewJSON(w http.ResponseWriter, req *http.Request) {
+	state := s.store.RLockState()
+	view := store.StateToView(state)
+	s.store.RUnlockState()
+
+	w.Header().Set("Content-Type", "application/json")
+	err := json.NewEncoder(w).Encode(view)
+	if err != nil {
+		http.Error(w, fmt.Sprintf("Error rendering view payload: %v", err), http.StatusInternalServerError)
+	}
+}