refactor: new go-libipfs/gateway API, deprecate Gateway.Writable (#9616)

cmd/ipfs/daemon.go

@@ -162,7 +162,7 @@ Headers.
 		cmds.StringOption(initProfileOptionKwd, "Configuration profiles to apply for --init. See ipfs init --help for more"),
 		cmds.StringOption(routingOptionKwd, "Overrides the routing option").WithDefault(routingOptionDefaultKwd),
 		cmds.BoolOption(mountKwd, "Mounts IPFS to the filesystem using FUSE (experimental)"),
-		cmds.BoolOption(writableKwd, "Enable writing objects (with POST, PUT and DELETE)"),
+		cmds.BoolOption(writableKwd, "Enable legacy Gateway.Writable (deprecated)"),
 		cmds.StringOption(ipfsMountKwd, "Path to the mountpoint for IPFS (if using --mount). Defaults to config setting."),
 		cmds.StringOption(ipnsMountKwd, "Path to the mountpoint for IPNS (if using --mount). Defaults to config setting."),
 		cmds.BoolOption(unrestrictedAPIAccessKwd, "Allow API access to unlisted hashes"),
@@ -791,7 +791,11 @@ func serveHTTPGateway(req *cmds.Request, cctx *oldcmds.Context) (<-chan error, e
 
 	writable, writableOptionFound := req.Options[writableKwd].(bool)
 	if !writableOptionFound {
-		writable = cfg.Gateway.Writable
+		writable = cfg.Gateway.Writable.WithDefault(false)
+	}
+
+	if writable {
+		log.Error("serveHTTPGateway: legacy Gateway.Writable is DEPRECATED and will be removed or changed in future versions. If you are still using this, provide feedback in https://github.com/ipfs/specs/issues/375")
 	}
 
 	listeners, err := sockets.TakeListeners("io.ipfs.gateway")

config/gateway.go

@@ -38,9 +38,9 @@ type Gateway struct {
 	// should be redirected.
 	RootRedirect string
 
-	// Writable enables PUT/POST request handling by this gateway. Usually,
-	// writing is done through the API, not the gateway.
-	Writable bool
+	// DEPRECATED: Enables legacy PUT/POST request handling.
+	// Modern replacement tracked in https://github.com/ipfs/specs/issues/375
+	Writable Flag `json:",omitempty"`
 
 	// PathPrefixes was removed: https://github.com/ipfs/go-ipfs/issues/7702
 	PathPrefixes []string

config/init.go

@@ -65,7 +65,6 @@ func InitWithIdentity(identity Identity) (*Config, error) {
 
 		Gateway: Gateway{
 			RootRedirect: "",
-			Writable:     false,
 			NoFetch:      false,
 			PathPrefixes: []string{},
 			HTTPHeaders: map[string][]string{

core/corehttp/gateway.go

@@ -1,12 +1,19 @@
 package corehttp
 
 import (
+	"context"
 	"fmt"
+	"io"
 	"net"
 	"net/http"
 
+	cid "github.com/ipfs/go-cid"
+	"github.com/ipfs/go-libipfs/blocks"
+	"github.com/ipfs/go-libipfs/files"
 	"github.com/ipfs/go-libipfs/gateway"
+	iface "github.com/ipfs/interface-go-ipfs-core"
 	options "github.com/ipfs/interface-go-ipfs-core/options"
+	"github.com/ipfs/interface-go-ipfs-core/path"
 	version "github.com/ipfs/kubo"
 	core "github.com/ipfs/kubo/core"
 	coreapi "github.com/ipfs/kubo/core/coreapi"
@@ -38,15 +45,45 @@ func GatewayOption(writable bool, paths ...string) ServeOption {
 			return nil, err
 		}
 
-		gateway := gateway.NewHandler(gateway.Config{
-			Headers:  headers,
-			Writable: writable,
-		}, api, offlineAPI)
+		gatewayConfig := gateway.Config{
+			Headers: headers,
+		}
+
+		gatewayAPI := &gatewayAPI{
+			api:        api,
+			offlineAPI: offlineAPI,
+		}
 
+		gateway := gateway.NewHandler(gatewayConfig, gatewayAPI)
 		gateway = otelhttp.NewHandler(gateway, "Gateway.Request")
 
+		var writableGateway *writableGatewayHandler
+		if writable {
+			writableGateway = &writableGatewayHandler{
+				config: &gatewayConfig,
+				api:    api,
+			}
+		}
+
 		for _, p := range paths {
-			mux.Handle(p+"/", gateway)
+			mux.HandleFunc(p+"/", func(w http.ResponseWriter, r *http.Request) {
+				if writable {
+					switch r.Method {
+					case http.MethodPost:
+						writableGateway.postHandler(w, r)
+					case http.MethodDelete:
+						writableGateway.deleteHandler(w, r)
+					case http.MethodPut:
+						writableGateway.putHandler(w, r)
+					default:
+						gateway.ServeHTTP(w, r)
+					}
+
+					return
+				}
+
+				gateway.ServeHTTP(w, r)
+			})
 		}
 		return mux, nil
 	}
@@ -62,3 +99,49 @@ func VersionOption() ServeOption {
 		return mux, nil
 	}
 }
+
+type gatewayAPI struct {
+	api        iface.CoreAPI
+	offlineAPI iface.CoreAPI
+}
+
+func (gw *gatewayAPI) GetUnixFsNode(ctx context.Context, pth path.Resolved) (files.Node, error) {
+	return gw.api.Unixfs().Get(ctx, pth)
+}
+
+func (gw *gatewayAPI) LsUnixFsDir(ctx context.Context, pth path.Resolved) (<-chan iface.DirEntry, error) {
+	// Optimization: use Unixfs.Ls without resolving children, but using the
+	// cumulative DAG size as the file size. This allows for a fast listing
+	// while keeping a good enough Size field.
+	return gw.api.Unixfs().Ls(ctx, pth,
+		options.Unixfs.ResolveChildren(false),
+		options.Unixfs.UseCumulativeSize(true),
+	)
+}
+
+func (gw *gatewayAPI) GetBlock(ctx context.Context, cid cid.Cid) (blocks.Block, error) {
+	r, err := gw.api.Block().Get(ctx, path.IpfsPath(cid))
+	if err != nil {
+		return nil, err
+	}
+
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return nil, err
+	}
+
+	return blocks.NewBlockWithCid(data, cid)
+}
+
+func (gw *gatewayAPI) GetIPNSRecord(ctx context.Context, c cid.Cid) ([]byte, error) {
+	return gw.api.Routing().Get(ctx, "/ipns/"+c.String())
+}
+
+func (gw *gatewayAPI) IsCached(ctx context.Context, pth path.Path) bool {
+	_, err := gw.offlineAPI.Block().Stat(ctx, pth)
+	return err == nil
+}
+
+func (gw *gatewayAPI) ResolvePath(ctx context.Context, pth path.Path) (path.Resolved, error) {
+	return gw.api.ResolvePath(ctx, pth)
+}