server: use custom error page

main.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Jeremy Baxter.
+// entry point for records
+
 package main
 
 import (
@@ -16,18 +19,33 @@ const version = "0-pre"
 
 var addr *string
 var port *uint16
+var tempDir *string
+var deleteAndExit *bool
 var regenerate *bool
 var showVersion *bool
 
 func main() {
 	addr = getopt.String('a', "0.0.0.0")
 	port = getopt.Uint16('p', 8000)
+	tempDir = getopt.String('t', "")
+	deleteAndExit = getopt.Bool('d')
 	regenerate = getopt.Bool('r')
 	showVersion = getopt.Bool('V')
 	if err := getopt.Getopt(nil); err != nil {
 		util.Die(err.Error())
 	}
 
+	if len(*tempDir) != 0 {
+		musicindex.TempDir = *tempDir
+	}
+
+	if *deleteAndExit {
+		err := os.RemoveAll(musicindex.TempDir)
+		if err != nil {
+			util.Die("cannot remove %s: %s", musicindex.TempDir, err.Error())
+		}
+		os.Exit(0)
+	}
 	if *showVersion {
 		fmt.Printf("records %s\n", version)
 		os.Exit(0)
@@ -35,13 +53,20 @@ func main() {
 
 	args := getopt.Args()
 	if len(args) != 1 {
-		fmt.Fprintf(os.Stderr, "usage: %s [-rV] [-a address] [-p port] directory\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "usage: %s [-drV] [-a address] [-p port] directory\n", os.Args[0])
 		os.Exit(1)
 	}
 
 	mediaDir := args[0]
 
-	log.Printf("This is records %s\n", version)
+	{
+		interactive := ""
+		if util.Interactive() {
+			interactive = ", running with interactive features"
+		}
+		log.Printf("This is records %s%s", version, interactive)
+	}
+
 	log.Println("https://git.baxters.nz/jeremy/records")
 
 	musicindex.Init(mediaDir, *regenerate)

musicindex/index.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Jeremy Baxter.
+// Music library indexing code
+
 package musicindex
 
 import (
@@ -113,11 +116,13 @@ func indexAlbums(artist *Artist) (albums map[string]Album) {
 
 	albums = make(map[string]Album)
 	for _, albumName := range entries {
-		util.Iprint("* index %s - %s\r", artist.Name, albumName)
+		util.Iprint("\033[2K\r   \033[1;36mcaching\033[0m %s - %s",
+			artist.Name, albumName)
 
 		albumDir := artistDir + "/" + albumName
 		album, err := indexAlbum(artist, albumName, albumDir)
 		if err != nil {
+			util.Iprint("\r")
 			log.Printf("warn: skipping inaccessible album %s: %s", albumName, err.Error())
 		} else {
 			albums[albumName] = album

musicindex/musicindex.go

@@ -1,7 +1,5 @@
-// musicindex.go
-// Copyright (c) 2025 Jeremy Baxter.
-
-// Ephemeral music (artist, album, cover & track) index
+// Copyright (c) 2026 Jeremy Baxter.
+// In-memory album and song database
 
 package musicindex
 

server/pages.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Jeremy Baxter.
+// HTML builders
+
 package server
 
 import (
@@ -28,7 +31,8 @@ type Page interface {
 func writePage(p Page, w http.ResponseWriter) {
 	t, err := template.ParseFS(staticFS, "static/templates/" + p.SourceFile())
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusInternalServerError)
+		http.Error(w, "Internal server error: " + err.Error(),
+			http.StatusInternalServerError)
 		return
 	}
 
@@ -38,13 +42,26 @@ func writePage(p Page, w http.ResponseWriter) {
 	}
 }
 
+type ErrorPage struct {
+	Status string
+	Reason string
+}
+
+func MakeErrorPage(status, reason string) (p ErrorPage) {
+	p.Status = status
+	p.Reason = reason
+	return
+}
+
+func (p ErrorPage) SourceFile() string { return "error.html" }
+func (p ErrorPage) Title() string { return "" }
+func (p ErrorPage) Body() template.HTML { return template.HTML("") }
+
 type IndexPage struct {
 	Showcase string
 }
 
-func MakeIndexPage() IndexPage {
-	var p IndexPage
-
+func MakeIndexPage() (p IndexPage) {
 	albums := musicindex.Albums()
 	rand.Shuffle(len(albums), func(i, j int) {
 		albums[i], albums[j] = albums[j], albums[i]
@@ -68,9 +85,11 @@ func MakeIndexPage() IndexPage {
 		}
 		b.WriteString(`</div>`)
 	}
+
 	b.WriteString(`</div>`)
 	p.Showcase = b.String()
-	return p
+
+	return
 }
 
 func (p IndexPage) SourceFile() string { return "base.html" }
@@ -99,8 +118,7 @@ func ArtistSortOptions() []string {
 	return []string{"name", "albums", "songs"}
 }
 
-func MakeArtistsPage(sortBy string) ArtistsPage {
-	var p ArtistsPage
+func MakeArtistsPage(sortBy string) (p ArtistsPage) {
 	var b strings.Builder
 
 	artistNames := musicindex.Artists()
@@ -135,9 +153,11 @@ func MakeArtistsPage(sortBy string) ArtistsPage {
 		b.WriteString(fmt.Sprintf("<br>%d album%s, %d songs</li><br>",
 			albums, util.OptionalString(albums != 1, "s"), artist.Songs))
 	}
+
 	b.WriteString(`</div>`)
 	p.bodyHTML = b.String()
-	return p
+
+	return
 }
 
 func (p ArtistsPage) SourceFile() string { return "base.html" }
@@ -193,14 +213,13 @@ func writeAlbums(b *strings.Builder, sortBy string, albums []musicindex.Album, a
 	b.WriteString(`</tbody></table></div>`)
 }
 
-func MakeAlbumsPage(sortBy string) AlbumsPage {
-	var p AlbumsPage
+func MakeAlbumsPage(sortBy string) (p AlbumsPage) {
 	var b strings.Builder
 
 	writeAlbums(&b, sortBy, musicindex.Albums(), false)
 	p.bodyHTML = b.String()
 
-	return p
+	return
 }
 
 func (p AlbumsPage) SourceFile() string { return "base.html" }
@@ -212,8 +231,7 @@ type ArtistPage struct {
 	bodyHTML string
 }
 
-func MakeArtistPage(sortBy string, name string) ArtistPage {
-	var p ArtistPage
+func MakeArtistPage(sortBy string, name string) (p ArtistPage) {
 	var b strings.Builder
 
 	artist := musicindex.FindArtist(name)
@@ -224,7 +242,7 @@ func MakeArtistPage(sortBy string, name string) ArtistPage {
 	p.Artist = artist
 	p.bodyHTML = b.String()
 
-	return p
+	return
 }
 
 func (p ArtistPage) SourceFile() string { return "base.html" }
@@ -236,8 +254,7 @@ type AlbumPage struct {
 	bodyHTML string
 }
 
-func MakeAlbumPage(album musicindex.Album) AlbumPage {
-	var p AlbumPage
+func MakeAlbumPage(album musicindex.Album) (p AlbumPage) {
 	var b strings.Builder
 
 	b.WriteString(`<br><div class="album"><div class="album-cover">`)
@@ -266,7 +283,7 @@ func MakeAlbumPage(album musicindex.Album) AlbumPage {
 	p.Album = album
 	p.bodyHTML = b.String()
 
-	return p
+	return
 }
 
 func (p AlbumPage) SourceFile() string { return "base.html" }

server/server.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Jeremy Baxter.
+// HTTP music server
+
 package server
 
 import (
@@ -25,6 +28,16 @@ var artistPages map[string]map[string]ArtistPage
 // mapping of artist names to album names to pages
 var albumPages map[string]map[string]AlbumPage
 
+func httpErrorReason(w http.ResponseWriter, error int, reason string) {
+	errorName := fmt.Sprintf("%d %s", error, http.StatusText(error))
+	w.WriteHeader(error)
+	writePage(MakeErrorPage(errorName, reason), w)
+}
+
+func httpError(w http.ResponseWriter, error int) {
+	httpErrorReason(w, error, "")
+}
+
 func doIndexPage(w http.ResponseWriter, req *http.Request) {
 	writePage(indexPage, w)
 }
@@ -61,13 +74,13 @@ func detectTextType(fileName string) string {
 
 func serveStaticFiles(w http.ResponseWriter, req *http.Request) {
 	if strings.HasPrefix(req.RequestURI, "/static/templates/") {
-		http.Error(w, "forbidden", http.StatusForbidden)
+		httpError(w, http.StatusForbidden)
 		return
 	}
 
 	contents, err := staticFS.ReadFile(req.RequestURI[1:])
 	if err != nil {
-		http.Error(w, err.Error(), http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 
@@ -83,30 +96,31 @@ func serveStaticFiles(w http.ResponseWriter, req *http.Request) {
 func serveMediaDirectory(w http.ResponseWriter, req *http.Request) {
 	path, err := url.QueryUnescape("/" + strings.SplitN(req.RequestURI[1:], "/", 2)[1])
 	if err != nil {
-		http.Error(w, "bad request", http.StatusBadRequest)
+		httpError(w, http.StatusBadRequest)
 		return
 	}
 
 	filePath := musicindex.MediaDirectory() + path
 
-	if strings.Contains(path, "/..") || strings.Contains(path, "/.") {
-		http.Error(w, "forbidden", http.StatusForbidden)
+	if strings.Contains(path, "/../") || strings.Contains(path, "/./") {
+		httpError(w, http.StatusForbidden)
 		return
 	}
 
 	stat, err := os.Stat(filePath)
 	if err != nil {
-		http.Error(w, "not found", http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 	if stat.IsDir() {
-		http.Error(w, "is a directory; maybe you are looking for " + path, http.StatusForbidden)
+		httpErrorReason(w, http.StatusForbidden,
+			"is a directory; maybe you are looking for " + path)
 		return
 	}
 
 	f, err := os.Open(filePath)
 	if err != nil {
-		http.Error(w, "not found", http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 	defer f.Close()
@@ -117,14 +131,14 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 	// test artist
 	rx, err := regexp.Compile("^/([^/?]+)/?(\\?.*)?$")
 	if err != nil {
-		http.Error(w, "internal server error", http.StatusInternalServerError)
+		httpError(w, http.StatusInternalServerError)
 		return
 	}
 
 	if (rx.MatchString(req.RequestURI)) {
 		artist, err := url.QueryUnescape(rx.FindStringSubmatch(req.RequestURI)[1])
 		if err != nil {
-			http.Error(w, "bad request", http.StatusBadRequest)
+			httpError(w, http.StatusBadRequest)
 			return
 		}
 		if musicindex.ArtistExists(artist) {
@@ -139,14 +153,14 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		}
 
 		// artist not found
-		http.Error(w, "not found", http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 
 	// test album tarball
 	rx, err = regexp.Compile("^/([^/?]+)/([^/?]+)\\.tar\\.gz$")
 	if err != nil {
-		http.Error(w, "internal server error", http.StatusInternalServerError)
+		httpError(w, http.StatusInternalServerError)
 		return
 	}
 
@@ -154,12 +168,12 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		captures := rx.FindStringSubmatch(req.RequestURI)
 		artist, err := url.QueryUnescape(captures[1])
 		if err != nil {
-			http.Error(w, "bad request", http.StatusBadRequest)
+			httpError(w, http.StatusBadRequest)
 			return
 		}
 		albumName, err := url.QueryUnescape(captures[2])
 		if err != nil {
-			http.Error(w, "bad request", http.StatusBadRequest)
+			httpError(w, http.StatusBadRequest)
 			return
 		}
 
@@ -168,8 +182,7 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 			if ok {
 				f, err := os.Open(album.Tarball)
 				if err != nil {
-					http.Error(w, "internal server error: " + err.Error(),
-						http.StatusInternalServerError)
+					httpErrorReason(w, http.StatusInternalServerError, err.Error())
 					return
 				}
 				defer f.Close()
@@ -184,14 +197,14 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		}
 
 		// artist or album not found
-		http.Error(w, "not found", http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 
 	// test album
 	rx, err = regexp.Compile("^/([^/?]+)/([^/?]+)/?(\\?.*)?$")
 	if err != nil {
-		http.Error(w, "internal server error", http.StatusInternalServerError)
+		httpErrorReason(w, http.StatusInternalServerError, err.Error())
 		return
 	}
 
@@ -199,12 +212,12 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		captures := rx.FindStringSubmatch(req.RequestURI)
 		artist, err := url.QueryUnescape(captures[1])
 		if err != nil {
-			http.Error(w, "bad request", http.StatusBadRequest)
+			httpError(w, http.StatusBadRequest)
 			return
 		}
 		albumName, err := url.QueryUnescape(captures[2])
 		if err != nil {
-			http.Error(w, "bad request", http.StatusBadRequest)
+			httpError(w, http.StatusBadRequest)
 			return
 		}
 
@@ -217,12 +230,12 @@ func handleArtistAlbumPage(w http.ResponseWriter, req *http.Request) {
 		}
 
 		// artist or album not found
-		http.Error(w, "not found", http.StatusNotFound)
+		httpError(w, http.StatusNotFound)
 		return
 	}
 
 	// illegal URI format
-	http.Error(w, "not found", http.StatusNotFound)
+	httpError(w, http.StatusNotFound)
 }
 
 func RunOn(address string) {

util/util.go

@@ -1,3 +1,6 @@
+// Copyright (c) 2026 Jeremy Baxter.
+// Reusable utility functions
+
 package util
 
 import (
@@ -83,9 +86,13 @@ func HashOf(s string) string {
 	return fmt.Sprintf("%x", h.Sum(nil))
 }
 
+func Interactive() bool {
+	return term.IsTerminal(int(os.Stderr.Fd()))
+}
+
 // print only if interactive
 func Iprint(format string, args ...any) {
-	if term.IsTerminal(int(os.Stderr.Fd())) {
+	if Interactive() {
 		fmt.Fprintf(os.Stderr, format, args...)
 	}
 }