Merge pull request #2631 from kobergj/go-embed

Go embed

ocis-pkg/assetsfs/assetsfs.go

@@ -0,0 +1,65 @@
+package assetsfs
+
+import (
+	"embed"
+	"fmt"
+	"io/fs"
+	"net/http"
+	"os"
+	"path"
+
+	"github.com/owncloud/ocis/ocis-pkg/log"
+)
+
+// FileSystem customized to load assets
+type FileSystem struct {
+	fs        http.FileSystem
+	assetPath string
+	log       log.Logger
+}
+
+// Open checks if assetPath is set and tries to load from there. Falls back to fs if that is not possible
+func (f *FileSystem) Open(original string) (http.File, error) {
+	if f.assetPath != "" {
+		file, err := read(f.assetPath, original)
+		if err == nil {
+			return file, nil
+		}
+		f.log.Warn().
+			Str("path", f.assetPath).
+			Str("filename", original).
+			Str("error", err.Error()).
+			Msg("error reading from assetPath")
+	}
+
+	return f.fs.Open(original)
+}
+
+// New initializes a new FileSystem. Quits on error
+func New(embedFS embed.FS, assetPath string, logger log.Logger) *FileSystem {
+	f, err := fs.Sub(embedFS, "assets")
+	if err != nil {
+		fmt.Println("Cannot load subtree fs:", err.Error())
+		os.Exit(1)
+	}
+
+	return &FileSystem{
+		fs:        http.FS(f),
+		assetPath: assetPath,
+		log:       logger,
+	}
+}
+
+// tries to read file from disk or errors
+func read(assetPath string, fileName string) (http.File, error) {
+	if stat, err := os.Stat(assetPath); err != nil || !stat.IsDir() {
+		return nil, fmt.Errorf("can't load asset path: %s", err)
+	}
+
+	p := path.Join(assetPath, fileName)
+	if _, err := os.Stat(p); err != nil {
+		return nil, err
+	}
+
+	return os.Open(p)
+}