Add cachePath variable and CLI option

cmd/gonic/main.go

@@ -20,6 +20,7 @@ func main() {
 	set := flag.NewFlagSet(version.NAME, flag.ExitOnError)
 	listenAddr := set.String("listen-addr", "0.0.0.0:4747", "listen address (optional)")
 	musicPath := set.String("music-path", "", "path to music")
+	cachePath := set.String("cache-path", "", "path to cache")
 	dbPath := set.String("db-path", "gonic.db", "path to database (optional)")
 	scanInterval := set.Int("scan-interval", 0, "interval (in minutes) to automatically scan music (optional)")
 	proxyPrefix := set.String("proxy-prefix", "", "url path prefix to use if behind proxy. eg '/gonic' (optional)")
@@ -39,6 +40,9 @@ func main() {
 	if _, err := os.Stat(*musicPath); os.IsNotExist(err) {
 		log.Fatal("please provide a valid music directory")
 	}
+	if _, err := os.Stat(*cachePath); os.IsNotExist(err) {
+		log.Fatal("please provide a valid cache directory")
+	}
 	db, err := db.New(*dbPath)
 	if err != nil {
 		log.Fatalf("error opening database: %v\n", err)
@@ -49,6 +53,7 @@ func main() {
 	serverOptions := server.Options{
 		DB:           db,
 		MusicPath:    *musicPath,
+		CachePath:    *cachePath,
 		ListenAddr:   *listenAddr,
 		ScanInterval: time.Duration(*scanInterval) * time.Minute,
 		ProxyPrefix:  *proxyPrefix,

server/ctrlbase/ctrl.go

@@ -47,6 +47,7 @@ func statusToBlock(code int) string {
 type Controller struct {
 	DB          *db.DB
 	MusicPath   string
+	CachePath   string
 	Scanner     *scanner.Scanner
 	ProxyPrefix string
 }

server/server.go

@@ -21,6 +21,7 @@ import (
 type Options struct {
 	DB           *db.DB
 	MusicPath    string
+	CachePath    string
 	ListenAddr   string
 	ScanInterval time.Duration
 	ProxyPrefix  string
@@ -35,11 +36,13 @@ type Server struct {
 func New(opts Options) *Server {
 	// ** begin sanitation
 	opts.MusicPath = filepath.Clean(opts.MusicPath)
+	opts.CachePath = filepath.Clean(opts.CachePath)
 	// ** begin controllers
 	scanner := scanner.New(opts.DB, opts.MusicPath)
 	base := &ctrlbase.Controller{
 		DB:          opts.DB,
 		MusicPath:   opts.MusicPath,
+		CachePath:   opts.CachePath,
 		ProxyPrefix: opts.ProxyPrefix,
 		Scanner:     scanner,
 	}