internal/rosa: access backing storage through fs

This is more versatile than hardcoding the os.Root implementation.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 14 insertions, 8 deletions

diff --git a/internal/rosa/mirror.go b/internal/rosa/mirror.go
index 3f7822e5..09419396 100644
--- a/internal/rosa/mirror.go
+++ b/internal/rosa/mirror.go
@@ -204,7 +204,7 @@ func (r Remote) Status(
 // NewMirror returns an [http.Handler] for servicing mirror requests.
 func NewMirror(
 	msg message.Msg,
-	base *os.Root,
+	fsys fs.FS,
 	key ed25519.PrivateKey,
 ) http.Handler {
 	const identName = "ident"
@@ -224,7 +224,7 @@ func NewMirror(
 		}
 
 		ids := pkg.Encode((pkg.Checksum)(buf[:len(pkg.Checksum{})]))
-		if linkname, err := base.Readlink(filepath.Join(
+		if linkname, err := fs.ReadLink(fsys, filepath.Join(
 			"identifier",
 			ids,
 		)); err != nil {
@@ -239,7 +239,7 @@ func NewMirror(
 			(*pkg.Checksum)(buf[len(pkg.Checksum{}):]),
 			filepath.Base(linkname),
 		); err != nil {
-			http.Error(w, err.Error(), http.StatusBadRequest)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return
 		}
 		msg.Verbosef("serving artifact %s", ids)
@@ -276,7 +276,7 @@ func NewMirror(
 
 		checksums := pkg.Encode(buf)
 		rel := filepath.Join("checksum", checksums)
-		if _, err := base.Lstat(rel); err != nil {
+		if _, err := fs.Lstat(fsys, rel); err != nil {
 			if errors.Is(err, os.ErrNotExist) {
 				w.WriteHeader(http.StatusNotFound)
 				return
@@ -287,7 +287,7 @@ func NewMirror(
 		}
 		msg.Verbosef("serving outcome %s", pkg.Encode(buf))
 
-		fsys, err := fs.Sub(base.FS(), rel)
+		_fsys, err := fs.Sub(fsys, rel)
 		if err != nil {
 			msg.GetLogger().Println(err)
 			w.WriteHeader(http.StatusInternalServerError)
@@ -301,7 +301,7 @@ func NewMirror(
 			return
 		}
 		w.Header().Set("Content-Encoding", "gzip")
-		if err = pkg.Write(fsys, ".", gw); err != nil {
+		if err = pkg.Write(_fsys, ".", gw); err != nil {
 			msg.Verbose(err)
 		}
 		if err = gw.Close(); err != nil {
@@ -323,7 +323,7 @@ func NewMirror(
 		}
 
 		ids := pkg.Encode((pkg.Checksum)(buf[:len(pkg.Checksum{})]))
-		f, err := base.Open(filepath.Join(
+		f, err := fsys.Open(filepath.Join(
 			"status",
 			ids,
 		))
@@ -336,6 +336,12 @@ func NewMirror(
 			w.WriteHeader(http.StatusInternalServerError)
 			return
 		}
+		s, ok := f.(io.Seeker)
+		if !ok {
+			msg.GetLogger().Println("backing filesystem does not support seek")
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
 		msg.Verbosef("serving status %s", ids)
 
 		h := sha512.New384()
@@ -348,7 +354,7 @@ func NewMirror(
 		if _, err = w.Write(append(ed25519.Sign(key, buf[:]), buf[:]...)); err != nil {
 			msg.Verbose(err)
 			return
-		} else if _, err = f.Seek(0, io.SeekStart); err != nil {
+		} else if _, err = s.Seek(0, io.SeekStart); err != nil {
 			msg.GetLogger().Println(err)
 			return
 		} else if _, err = io.Copy(w, f); err != nil {