Separate out ui handler under build tag (#170)

Makefile

@@ -22,8 +22,9 @@ cleangen:
 	@rm -f ${GENERATED_CODE}
 
 dev: BUILD_TAGS+=dev
+dev: BUILD_TAGS+=ui
 dev: build-ui-ifne
-	@echo "==> Building Watchtower with dev features enabled"
+	@echo "==> Building Watchtower with dev and UI features enabled"
 	@CGO_ENABLED=$(CGO_ENABLED) BUILD_TAGS='$(BUILD_TAGS)' WATCHTOWER_DEV_BUILD=1 sh -c "'$(CURDIR)/scripts/build.sh'"
 
 build-ui:

internal/servers/controller/handler.go

@@ -24,7 +24,6 @@ import (
 	"github.com/hashicorp/watchtower/internal/servers/controller/handlers/projects"
 	"github.com/hashicorp/watchtower/internal/servers/controller/handlers/roles"
 	"github.com/hashicorp/watchtower/internal/servers/controller/handlers/users"
-	"github.com/hashicorp/watchtower/internal/ui"
 )
 
 type HandlerProperties struct {
@@ -51,63 +50,6 @@ func (c *Controller) handler(props HandlerProperties) (http.Handler, error) {
 	return commonWrappedHandler, nil
 }
 
-func handleUi(c *Controller) http.Handler {
-	var nextHandler http.Handler
-	if c.conf.RawConfig.PassthroughDirectory != "" {
-		nextHandler = ui.DevPassthroughHandler(c.logger, c.conf.RawConfig.PassthroughDirectory)
-	} else {
-		nextHandler = http.FileServer(ui.AssetFile())
-	}
-
-	rootHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		switch r.URL.Path {
-		case "/":
-			irw := newIndexResponseWriter(c.conf.DefaultOrgId)
-			nextHandler.ServeHTTP(irw, r)
-			irw.writeToWriter(w)
-
-		default:
-			nextHandler.ServeHTTP(w, r)
-		}
-	})
-
-	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
-		if r.Method != http.MethodGet {
-			w.WriteHeader(http.StatusMethodNotAllowed)
-			return
-		}
-
-		dotIndex := strings.LastIndex(r.URL.Path, ".")
-		switch dotIndex {
-		case -1:
-			// For all paths without an extension serve /index.html
-			r.URL.Path = "/"
-
-		default:
-			switch r.URL.Path {
-			case "/", "/favicon.png", "/assets/styles.css":
-
-			default:
-				for i := dotIndex + 1; i < len(r.URL.Path); i++ {
-					intVal := r.URL.Path[i]
-					// Current guidance from FE is if it's only alphanum after
-					// the last dot, treat it as an extension
-					if intVal < '0' ||
-						(intVal > '9' && intVal < 'A') ||
-						(intVal > 'Z' && intVal < 'a') ||
-						intVal > 'z' {
-						// Not an extension. Serve the contents of index.html
-						r.URL.Path = "/"
-					}
-				}
-			}
-		}
-
-		// Fall through to the next handler
-		rootHandler.ServeHTTP(w, r)
-	})
-}
-
 func handleGrpcGateway(c *Controller) (http.Handler, error) {
 	// Register*ServiceHandlerServer methods ignore the passed in ctx.  Using the baseContext now just in case this changes
 	// in the future, at which point we'll want to be using the baseContext.

internal/servers/controller/handler_noui.go

@@ -1,4 +1,4 @@
-package ui
+package controller
 
 import (
 	"net/http"
@@ -7,7 +7,7 @@ import (
 	"github.com/hashicorp/go-hclog"
 )
 
-func DevPassthroughHandler(logger hclog.Logger, passthroughDir string) http.Handler {
+func devPassthroughHandler(logger hclog.Logger, passthroughDir string) http.Handler {
 	// Panic may not be ideal but this is never a production call and it'll
 	// panic on startup. We could also just change the function to return
 	// an error.
@@ -21,3 +21,12 @@ func DevPassthroughHandler(logger hclog.Logger, passthroughDir string) http.Hand
 
 	return prefixHandler
 }
+
+var handleUi = func(c *Controller) http.Handler {
+	if c.conf.RawConfig.PassthroughDirectory != "" {
+		return devPassthroughHandler(c.logger, c.conf.RawConfig.PassthroughDirectory)
+	}
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		w.WriteHeader(http.StatusNotFound)
+	})
+}

internal/servers/controller/handler_ui.go

@@ -0,0 +1,71 @@
+// +build ui
+
+package controller
+
+import (
+	"net/http"
+	"strings"
+
+	"github.com/hashicorp/watchtower/internal/ui"
+)
+
+func init() {
+	handleUi = handleUiWithAssets
+}
+
+func handleUiWithAssets(c *Controller) http.Handler {
+	var nextHandler http.Handler
+	if c.conf.RawConfig.PassthroughDirectory != "" {
+		nextHandler = devPassthroughHandler(c.logger, c.conf.RawConfig.PassthroughDirectory)
+	} else {
+		nextHandler = http.FileServer(ui.AssetFile())
+	}
+
+	rootHandler := http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		switch r.URL.Path {
+		case "/":
+			irw := newIndexResponseWriter(c.conf.DefaultOrgId)
+			nextHandler.ServeHTTP(irw, r)
+			irw.writeToWriter(w)
+
+		default:
+			nextHandler.ServeHTTP(w, r)
+		}
+	})
+
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != http.MethodGet {
+			w.WriteHeader(http.StatusMethodNotAllowed)
+			return
+		}
+
+		dotIndex := strings.LastIndex(r.URL.Path, ".")
+		switch dotIndex {
+		case -1:
+			// For all paths without an extension serve /index.html
+			r.URL.Path = "/"
+
+		default:
+			switch r.URL.Path {
+			case "/", "/favicon.png", "/assets/styles.css":
+
+			default:
+				for i := dotIndex + 1; i < len(r.URL.Path); i++ {
+					intVal := r.URL.Path[i]
+					// Current guidance from FE is if it's only alphanum after
+					// the last dot, treat it as an extension
+					if intVal < '0' ||
+						(intVal > '9' && intVal < 'A') ||
+						(intVal > 'Z' && intVal < 'a') ||
+						intVal > 'z' {
+						// Not an extension. Serve the contents of index.html
+						r.URL.Path = "/"
+					}
+				}
+			}
+		}
+
+		// Fall through to the next handler
+		rootHandler.ServeHTTP(w, r)
+	})
+}