ipfs, http: support downloading directory files

http/api.go

@@ -55,7 +55,7 @@ func (as *apiServer) handlePin(jc jape.Context) {
 		return
 	}
 
-	r, err := as.node.DownloadCID(ctx, cid)
+	r, err := as.node.DownloadCID(ctx, cid, nil)
 	if err != nil {
 		jc.Error(err, http.StatusInternalServerError)
 		return

http/ipfs.go

@@ -1,8 +1,10 @@
 package http
 
 import (
+	"errors"
 	"io"
 	"net/http"
+	"strings"
 
 	"github.com/ipfs/go-cid"
 	format "github.com/ipfs/go-ipld-format"
@@ -24,9 +26,23 @@ type ipfsServer struct {
 func (is *ipfsServer) handleIPFS(jc jape.Context) {
 	ctx := jc.Request.Context()
 
+	var pathStr string
+	if err := jc.DecodeParam("path", &pathStr); err != nil {
+		return
+	}
+
 	var cidStr string
-	if err := jc.DecodeParam("cid", &cidStr); err != nil {
+	is.log.Debug("downloading file", zap.String("path", pathStr))
+	pathStr = strings.TrimPrefix(pathStr, "/") // remove leading slash
+	path := strings.Split(pathStr, "/")
+	if len(path) == 0 || path[0] == "" {
+		jc.Error(errors.New("bad path"), http.StatusBadRequest)
 		return
+	} else if len(path) == 1 {
+		cidStr = path[0]
+	} else {
+		cidStr = path[0]
+		path = path[1:]
 	}
 
 	cid, err := cid.Parse(cidStr)
@@ -38,7 +54,7 @@ func (is *ipfsServer) handleIPFS(jc jape.Context) {
 	block, err := is.store.GetBlock(ctx, cid)
 	if format.IsNotFound(err) && is.ipfs.FetchRemote {
 		is.log.Info("downloading from ipfs", zap.String("cid", cid.Hash().B58String()))
-		r, err := is.node.DownloadCID(ctx, cid)
+		r, err := is.node.DownloadCID(ctx, cid, path)
 		if err != nil {
 			jc.Error(err, http.StatusInternalServerError)
 			is.log.Error("failed to download cid", zap.Error(err))
@@ -81,6 +97,6 @@ func NewIPFSHandler(node *ipfs.Node, store Store, cfg config.Config, log *zap.Lo
 	}
 
 	return jape.Mux(map[string]jape.Handler{
-		"GET /ipfs/:cid": s.handleIPFS,
+		"GET /ipfs/*path": s.handleIPFS,
 	})
 }

ipfs/node.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/ipfs/boxo/bitswap"
 	bnetwork "github.com/ipfs/boxo/bitswap/network"
@@ -55,14 +56,42 @@ func (n *Node) Close() error {
 }
 
 // DownloadCID downloads the CID
-func (n *Node) DownloadCID(ctx context.Context, c cid.Cid) (io.ReadSeekCloser, error) {
+func (n *Node) DownloadCID(ctx context.Context, c cid.Cid, path []string) (io.ReadSeekCloser, error) {
 	dagSess := merkledag.NewSession(ctx, n.dagService)
 	rootNode, err := dagSess.Get(ctx, c)
 	if err != nil {
 		return nil, fmt.Errorf("failed to get root node: %w", err)
 	}
 
-	dr, err := fsio.NewDagReader(ctx, rootNode, dagSess)
+	var traverse func(context.Context, format.Node, []string) (format.Node, error)
+	traverse = func(ctx context.Context, parent format.Node, path []string) (format.Node, error) {
+		if len(path) == 0 {
+			return parent, nil
+		}
+
+		childLink, rem, err := parent.Resolve(path)
+		if err != nil {
+			return nil, fmt.Errorf("failed to resolve path %q: %w", strings.Join(path, "/"), err)
+		}
+
+		switch v := childLink.(type) {
+		case *format.Link:
+			childNode, err := dagSess.Get(ctx, v.Cid)
+			if err != nil {
+				return nil, fmt.Errorf("failed to get child node %q: %w", v.Cid, err)
+			}
+			return traverse(ctx, childNode, rem)
+		default:
+			return nil, fmt.Errorf("expected link node, got %T", childLink)
+		}
+	}
+
+	node, err := traverse(ctx, rootNode, path)
+	if err != nil {
+		return nil, fmt.Errorf("failed to traverse path: %w", err)
+	}
+
+	dr, err := fsio.NewDagReader(ctx, node, dagSess)
 	return dr, err
 }