Added 1.16+ embed mode

Author: bmurray

Makefile

@@ -1,5 +1,5 @@
 run: pkged.go 
-	go run main.go pkged.go -mode embed
+	go run main.go pkged.go -mode pkger
 
 pkged.go: react-app/build
 	pkger -o ./ -include /react-app/build

README.md

@@ -17,11 +17,13 @@ Usage of go-react:
   -dir string
         Directory where the static built app resides (default "./react-app/build/")
   -embed string
-        Directory where the static built embeded app resides (default "/react-app/build/")
+        Directory where the static built embeded app resides (1.16+) (default "react-app/build")
   -listen string
         Listen on address (default ":8080")
   -mode string
-        Mode to serve REACT site: proxy, dir, embed (default "proxy")
+        Mode to serve REACT site: proxy, dir, pkger, embed  (default "proxy")
+  -pkger string
+        Directory where the static built embeded app resides (default "/react-app/build/")
   -proxy string
         Address to proxy requests to (default "http://localhost:3000/")
 ```
@@ -66,7 +68,7 @@ go run main.go -mode dir
 ```
 
 
-### Embed mode
+### Packaged mode (pre 1.16)
 
 This method will build the react code into a deployment/production version, then embed it in the binary. This means you only need to produce a single binary for distribution without needing to deploy the react code as well. I find this very useful for programs that need a user interface but dont want the heft of a full update system. 
 
@@ -93,11 +95,31 @@ Build and run the binary
 ```
 go build -o go-react main.go pkged.go
 
-./go-react -mode embed
+./go-react -mode pkger
 
 ```
 
 Alternatively, the Makefile has all these steps:
 ```
 make run
-```
+```
+
+### Embed mode (1.16+)
+
+This provides the same methods as the packager method, but uses the new 1.16+ interface. 
+
+First, build the react code into a deployment/production version
+
+```
+cd react-app/
+npm build
+```
+
+Next, run the code. The files are automatically embeded. 
+
+```
+go run main.go -mode embed
+```
+
+
+

go.mod

@@ -1,5 +1,5 @@
 module github.com/bmurray/go-react
 
-go 1.15
+go 1.16
 
 require github.com/markbates/pkger v0.17.1

main.go

@@ -1,8 +1,10 @@
 package main
 
 import (
+	"embed"
 	"encoding/json"
 	"flag"
+	"io/fs"
 	"log"
 	"net/http"
 	"net/http/httputil"
@@ -12,14 +14,19 @@ import (
 	"github.com/markbates/pkger"
 )
 
+//go:embed react-app/build
+var embeded embed.FS
+
 func main() {
-	mode := flag.String("mode", "proxy", "Mode to serve REACT site: proxy, dir, embed")
+	mode := flag.String("mode", "proxy", "Mode to serve REACT site: proxy, dir, pkger, embed ")
 	// Proxy mode proxies all other connections to the npm server
 	proxy := flag.String("proxy", "http://localhost:3000/", "Address to proxy requests to")
 	// Dir follows general filesystem pathing rules
 	dir := flag.String("dir", "./react-app/build/", "Directory where the static built app resides")
 	// Embed needs to be absolute, based on the arguments of pkger. See Makefile
-	embed := flag.String("embed", "/react-app/build/", "Directory where the static built embeded app resides")
+	packaged := flag.String("pkger", "/react-app/build/", "Directory where the static built embeded app resides")
+	// Embed uses the new 1.16 embed functions to offer what pkger does
+	embed := flag.String("embed", "react-app/build", "Directory where the static built embeded app resides (1.16+)")
 	listen := flag.String("listen", ":8080", "Listen on address")
 	flag.Parse()
 
@@ -40,9 +47,17 @@ func main() {
 	case "dir":
 		// Dir mode is useful if you build your react app but don't want to embed it in the binary, such as Docker deploys
 		mux.Handle("/", http.FileServer(EmbedDir{http.Dir(*dir)}))
+	case "pkger":
+		// Pkger mode serves files that are embedded in the binary. Very useful for one-file distribution
+		mux.Handle("/", http.FileServer(EmbedDir{pkger.Dir(*packaged)}))
 	case "embed":
-		// Embed mode serves files that are embedded in the binary. Very useful for one-file distribution
-		mux.Handle("/", http.FileServer(EmbedDir{pkger.Dir(*embed)}))
+		// Embed uses the new 1.16+ Embed functionality
+		filesystem := fs.FS(embeded)
+		static, err := fs.Sub(filesystem, *embed)
+		if err != nil {
+			log.Fatal("Cannot open filesystem", err)
+		}
+		mux.Handle("/", http.FileServer(EmbedDir{http.FS(static)}))
 	default:
 		// Any other mode would assume you have a reverse proxy, like nginx, that filters traffic
 		log.Println("No react mode; this only works if you have a frontend reverse proxy")