switched to go-mod, updated codegangsta/cli -> urfave/cli

vendor/github.com/elazarl/go-bindata-assetfs/README.md

@@ -41,6 +41,6 @@ use
      ...
      http.Handle("/",
         http.FileServer(
-        &assetfs.AssetFS{Asset: Asset, AssetDir: AssetDir, Prefix: "data"}))
+        &assetfs.AssetFS{Asset: Asset, AssetDir: AssetDir, AssetInfo: AssetInfo, Prefix: "data"}))
 
 to serve files embedded from the `data` directory.

vendor/github.com/elazarl/go-bindata-assetfs/assetfs.go

@@ -9,11 +9,12 @@ import (
 	"os"
 	"path"
 	"path/filepath"
+	"strings"
 	"time"
 )
 
 var (
-	fileTimestamp = time.Now()
+	defaultFileTimestamp = time.Now()
 )
 
 // FakeFile implements os.FileInfo interface for a given path and size
@@ -24,6 +25,8 @@ type FakeFile struct {
 	Dir bool
 	// Len is the length of the fake file, zero if it is a directory
 	Len int64
+	// Timestamp is the ModTime of this file
+	Timestamp time.Time
 }
 
 func (f *FakeFile) Name() string {
@@ -40,7 +43,7 @@ func (f *FakeFile) Mode() os.FileMode {
 }
 
 func (f *FakeFile) ModTime() time.Time {
-	return fileTimestamp
+	return f.Timestamp
 }
 
 func (f *FakeFile) Size() int64 {
@@ -62,11 +65,14 @@ type AssetFile struct {
 	FakeFile
 }
 
-func NewAssetFile(name string, content []byte) *AssetFile {
+func NewAssetFile(name string, content []byte, timestamp time.Time) *AssetFile {
+	if timestamp.IsZero() {
+		timestamp = defaultFileTimestamp
+	}
 	return &AssetFile{
 		bytes.NewReader(content),
 		ioutil.NopCloser(nil),
-		FakeFile{name, false, int64(len(content))}}
+		FakeFile{name, false, int64(len(content)), timestamp}}
 }
 
 func (f *AssetFile) Readdir(count int) ([]os.FileInfo, error) {
@@ -92,13 +98,13 @@ func NewAssetDirectory(name string, children []string, fs *AssetFS) *AssetDirect
 	fileinfos := make([]os.FileInfo, 0, len(children))
 	for _, child := range children {
 		_, err := fs.AssetDir(filepath.Join(name, child))
-		fileinfos = append(fileinfos, &FakeFile{child, err == nil, 0})
+		fileinfos = append(fileinfos, &FakeFile{child, err == nil, 0, time.Time{}})
 	}
 	return &AssetDirectory{
 		AssetFile{
 			bytes.NewReader(nil),
 			ioutil.NopCloser(nil),
-			FakeFile{name, true, 0},
+			FakeFile{name, true, 0, time.Time{}},
 		},
 		0,
 		fileinfos}
@@ -127,6 +133,8 @@ type AssetFS struct {
 	Asset func(path string) ([]byte, error)
 	// AssetDir should return list of files in the path
 	AssetDir func(path string) ([]string, error)
+	// AssetInfo should return the info of file in path if exists
+	AssetInfo func(path string) (os.FileInfo, error)
 	// Prefix would be prepended to http requests
 	Prefix string
 }
@@ -137,11 +145,23 @@ func (fs *AssetFS) Open(name string) (http.File, error) {
 		name = name[1:]
 	}
 	if b, err := fs.Asset(name); err == nil {
-		return NewAssetFile(name, b), nil
+		timestamp := defaultFileTimestamp
+		if fs.AssetInfo != nil {
+			if info, err := fs.AssetInfo(name); err == nil {
+				timestamp = info.ModTime()
+			}
+		}
+		return NewAssetFile(name, b, timestamp), nil
 	}
 	if children, err := fs.AssetDir(name); err == nil {
 		return NewAssetDirectory(name, children, fs), nil
 	} else {
+		// If the error is not found, return an error that will
+		// result in a 404 error. Otherwise the server returns
+		// a 500 error for files not found.
+		if strings.Contains(err.Error(), "not found") {
+			return nil, os.ErrNotExist
+		}
 		return nil, err
 	}
 }