Revert "Allow user specified cache directory (#12)" (#111)

This reverts commit 2d512c5e47.

cmd/trivy/main.go

@@ -101,10 +101,6 @@ OPTIONS:
 			Name:  "debug, d",
 			Usage: "debug mode",
 		},
-		cli.StringFlag{
-			Name:  "cache-dir",
-			Usage: "cache directory",
-		},
 		cli.StringFlag{
 			Name:  "vuln-type",
 			Value: "os,library",

pkg/db/db.go

@@ -16,10 +16,10 @@ import (
 
 var (
 	db    *bolt.DB
+	dbDir = filepath.Join(utils.CacheDir(), "db")
 )
 
 func Init() (err error) {
-	dbDir := filepath.Join(utils.CacheDir(), "db")
 	if err = os.MkdirAll(dbDir, 0700); err != nil {
 		return xerrors.Errorf("failed to mkdir: %w", err)
 	}
@@ -45,7 +45,6 @@ func Reset() error {
 		return xerrors.Errorf("failed to reset DB: %w", err)
 	}
 
-	dbDir := filepath.Join(utils.CacheDir(), "db")
 	if err := os.RemoveAll(dbDir); err != nil {
 		return xerrors.Errorf("failed to reset DB: %w", err)
 	}

pkg/run.go

@@ -27,12 +27,6 @@ func Run(c *cli.Context) (err error) {
 	if err = log.InitLogger(debug); err != nil {
 		l.Fatal(err)
 	}
-
-	cacheDir := c.String("cache-dir")
-	if cacheDir != "" {
-		utils.SetCacheDir(cacheDir)
-	}
-
 	log.Logger.Debugf("cache dir:  %s", utils.CacheDir())
 
 	reset := c.Bool("reset")

pkg/utils/utils.go

@@ -12,24 +12,15 @@ import (
 	"golang.org/x/xerrors"
 )
 
-var cacheDir string
-
 func CacheDir() string {
-	if cacheDir == "" {
-		var err error
-		cacheDir, err = os.UserCacheDir()
+	cacheDir, err := os.UserCacheDir()
 	if err != nil {
 		cacheDir = os.TempDir()
 	}
-	}
 	dir := filepath.Join(cacheDir, "trivy")
 	return dir
 }
 
-func SetCacheDir(cd string) {
-	cacheDir = cd
-}
-
 func FileWalk(root string, targetFiles map[string]struct{}, walkFn func(r io.Reader, path string) error) error {
 	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
 		if info.IsDir() {