One dockerfile to rule them all

api/server.go

@@ -6,6 +6,7 @@ import (
 	"net/url"
 	"os"
 	"path"
+	"path/filepath"
 
 	"github.com/gorilla/mux"
 
@@ -23,6 +24,49 @@ import (
 
 const defaultPort = "4001"
 
+// spaHandler implements the http.Handler interface, so we can use it
+// to respond to HTTP requests. The path to the static directory and
+// path to the index file within that static directory are used to
+// serve the SPA in the given static directory.
+type spaHandler struct {
+	staticPath string
+	indexPath  string
+}
+
+// ServeHTTP inspects the URL path to locate a file within the static dir
+// on the SPA handler. If a file is found, it will be served. If not, the
+// file located at the index path on the SPA handler will be served. This
+// is suitable behavior for serving an SPA (single page application).
+func (h spaHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	// get the absolute path to prevent directory traversal
+	path, err := filepath.Abs(r.URL.Path)
+	if err != nil {
+		// if we failed to get the absolute path respond with a 400 bad request
+		// and stop
+		http.Error(w, err.Error(), http.StatusBadRequest)
+		return
+	}
+
+	// prepend the path with the path to the static directory
+	path = filepath.Join(h.staticPath, path)
+
+	// check whether a file exists at the given path
+	_, err = os.Stat(path)
+	if os.IsNotExist(err) {
+		// file does not exist, serve index.html
+		http.ServeFile(w, r, filepath.Join(h.staticPath, h.indexPath))
+		return
+	} else if err != nil {
+		// if we got an error (that wasn't that the file doesn't exist) stating the
+		// file, return a 500 internal server error and stop
+		http.Error(w, err.Error(), http.StatusInternalServerError)
+		return
+	}
+
+	// otherwise, use http.FileServer to serve the static dir
+	http.FileServer(http.Dir(h.staticPath)).ServeHTTP(w, r)
+}
+
 func main() {
 
 	if err := godotenv.Load(); err != nil {
@@ -68,14 +112,14 @@ func main() {
 	endpointRouter := rootRouter.PathPrefix(endpointURL.Path).Subrouter()
 
 	if devMode {
-		endpointRouter.Handle("/", handler.Playground("GraphQL playground", path.Join(endpointURL.Path, "/graphql")))
+		endpointRouter.Handle("/api", handler.Playground("GraphQL playground", path.Join(endpointURL.Path, "/graphql")))
 	} else {
-		endpointRouter.HandleFunc("/", func(w http.ResponseWriter, req *http.Request) {
+		endpointRouter.HandleFunc("/api", func(w http.ResponseWriter, req *http.Request) {
 			w.Write([]byte("photoview api endpoint"))
 		})
 	}
 
-	endpointRouter.Handle("/graphql",
+	endpointRouter.Handle("/api/graphql",
 		handler.GraphQL(photoview_graphql.NewExecutableSchema(graphqlConfig),
 			handler.IntrospectionEnabled(devMode),
 			handler.WebsocketUpgrader(server.WebsocketUpgrader(devMode)),
@@ -83,9 +127,12 @@ func main() {
 		),
 	)
 
-	photoRouter := endpointRouter.PathPrefix("/photo").Subrouter()
+	photoRouter := endpointRouter.PathPrefix("/api/photo").Subrouter()
 	routes.RegisterPhotoRoutes(db, photoRouter)
 
+	spa := spaHandler{staticPath: "/ui", indexPath: "index.html"}
+	endpointRouter.PathPrefix("/").Handler(spa)
+
 	if devMode {
 		log.Printf("🚀 Graphql playground ready at %s", endpointURL.String())
 	} else {