Added initial support for P2P-based image distribution

Signed-off-by: Yinuo Deng <i@dyn.im>

cmd/dist-receiver/main.go

@@ -0,0 +1,316 @@
+// Copyright © 2023 Alibaba Group Holding Ltd.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package main
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	b64 "encoding/base64"
+	"flag"
+	"fmt"
+	"io"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strings"
+	"sync"
+	"time"
+
+	config "github.com/ipfs/go-ipfs-config"
+	files "github.com/ipfs/go-ipfs-files"
+	"github.com/ipfs/go-ipfs/core"
+	"github.com/ipfs/go-ipfs/core/coreapi"
+	"github.com/ipfs/go-ipfs/core/node/libp2p"
+	"github.com/ipfs/go-ipfs/plugin/loader"
+	"github.com/ipfs/go-ipfs/repo/fsrepo"
+	icore "github.com/ipfs/interface-go-ipfs-core"
+	icorepath "github.com/ipfs/interface-go-ipfs-core/path"
+	"github.com/libp2p/go-libp2p-core/peer"
+	ma "github.com/multiformats/go-multiaddr"
+)
+
+var stageNow int
+var sig chan struct{}
+var targets []string
+
+func main() {
+	bootstrap := flag.String("bootstrap", "", "Specify the bootstrap node")
+	cidArg := flag.String("cid", "", "Specify the CID")
+	fileName := flag.String("filename", "", "Specify the name of the file to be distributed")
+	targetDir := flag.String("target", "", "Specify the target directory")
+
+	flag.Parse()
+
+	stageNow = 0
+	sig = make(chan struct{})
+
+	server := &http.Server{
+		Addr:         "0.0.0.0:4002",
+		ReadTimeout:  5 * time.Second,
+		WriteTimeout: 5 * time.Second,
+		IdleTimeout:  600 * time.Second,
+	}
+
+	http.HandleFunc("/stage", stage)
+	http.HandleFunc("/next", next)
+	http.HandleFunc("/connect", connect)
+	go func() {
+		if err := server.ListenAndServe(); err != nil {
+			panic(fmt.Errorf("failed to spawn command receiver: %s", err))
+		}
+	}()
+
+	ctx, cancel := context.WithCancel(context.Background())
+	defer cancel()
+
+	defer func() {
+		if err := os.RemoveAll(*fileName); err != nil {
+			fmt.Fprintf(os.Stderr, "Failed to clean up %s: %s\n", *fileName, err)
+		}
+	}()
+
+	node, _, err := spawnEphemeral(ctx, *bootstrap)
+	if err != nil {
+		panic(fmt.Errorf("failed to spawn ephemeral node: %s", err))
+	}
+
+	if err := connectToPeers(ctx, node, []string{*bootstrap}); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to connect to root peer: %s\n", err)
+	}
+
+	stageNow = 1
+
+	<-sig
+
+	if err := connectToPeers(ctx, node, targets); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to connect to peers: %s\n", err)
+	}
+
+	cid := icorepath.New(*cidArg)
+
+	if err := node.Dht().Provide(ctx, cid); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to seed the resource file: %s\n", err)
+	}
+
+	if err := node.Pin().Add(ctx, cid); err != nil {
+		fmt.Fprintf(os.Stderr, "Failed to pin the resource file: %s\n", err)
+	}
+
+	rootNode, err := node.Unixfs().Get(ctx, cid)
+
+	if err != nil {
+		panic(fmt.Errorf("could not get file with CID: %s", err))
+	}
+
+	if err := files.WriteTo(rootNode, *fileName); err != nil {
+		panic(fmt.Errorf("could not write out the fetched CID: %s", err))
+	}
+
+	if err := os.MkdirAll(*targetDir, os.ModePerm); err != nil {
+		panic(fmt.Errorf("failed to create target directory: %s", err))
+	}
+
+	if err := extractTarGz(*fileName, *targetDir); err != nil {
+		panic(fmt.Errorf("failed to uncompress resource file: %s", err))
+	}
+
+	stageNow = 2
+
+	<-sig
+}
+
+func createNode(ctx context.Context, repoPath string) (*core.IpfsNode, error) {
+	// Open the repo
+	repo, err := fsrepo.Open(repoPath)
+	if err != nil {
+		return nil, err
+	}
+
+	// Construct the node
+	nodeOptions := &core.BuildCfg{
+		Online:  true,
+		Routing: libp2p.DHTOption, // This option sets the node to be a full DHT node (both fetching and storing DHT Records)
+		// Routing: libp2p.DHTClientOption, // This option sets the node to be a client DHT node (only fetching records)
+		Repo: repo,
+	}
+
+	return core.NewNode(ctx, nodeOptions)
+}
+
+func spawnEphemeral(ctx context.Context, bootstrap string) (icore.CoreAPI, *core.IpfsNode, error) {
+	if err := setupPlugins(""); err != nil {
+		return nil, nil, err
+	}
+
+	repoPath, err := createTempRepo(bootstrap)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to create temp repo: %s", err)
+	}
+
+	node, err := createNode(ctx, repoPath)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	api, err := coreapi.NewCoreAPI(node)
+
+	return api, node, err
+}
+
+func setupPlugins(externalPluginsPath string) error {
+	plugins, err := loader.NewPluginLoader(filepath.Join(externalPluginsPath, "plugins"))
+	if err != nil {
+		return fmt.Errorf("error loading plugins: %s", err)
+	}
+
+	if err := plugins.Initialize(); err != nil {
+		return fmt.Errorf("error initializing plugins: %s", err)
+	}
+
+	if err := plugins.Inject(); err != nil {
+		return fmt.Errorf("error injecting plugins: %s", err)
+	}
+
+	return nil
+}
+
+func createTempRepo(bootstrap string) (string, error) {
+	repoPath, err := os.MkdirTemp("", "ipfs-shell")
+	if err != nil {
+		return "", fmt.Errorf("failed to get temp dir: %s", err)
+	}
+
+	cfg, err := config.Init(io.Discard, 2048)
+	if err != nil {
+		return "", err
+	}
+
+	cfg.Bootstrap = nil
+
+	if err := fsrepo.Init(repoPath, cfg); err != nil {
+		return "", fmt.Errorf("failed to init ephemeral node: %s", err)
+	}
+
+	return repoPath, nil
+}
+
+func connectToPeers(ctx context.Context, ipfs icore.CoreAPI, peers []string) error {
+	var wg sync.WaitGroup
+	peerInfos := make(map[peer.ID]*peer.AddrInfo, len(peers))
+	for _, addrStr := range peers {
+		addr, err := ma.NewMultiaddr(addrStr)
+		if err != nil {
+			return err
+		}
+		pii, err := peer.AddrInfoFromP2pAddr(addr)
+		if err != nil {
+			return err
+		}
+		pi, ok := peerInfos[pii.ID]
+		if !ok {
+			pi = &peer.AddrInfo{ID: pii.ID}
+			peerInfos[pi.ID] = pi
+		}
+		pi.Addrs = append(pi.Addrs, pii.Addrs...)
+	}
+
+	wg.Add(len(peerInfos))
+	for _, peerInfo := range peerInfos {
+		go func(peerInfo *peer.AddrInfo) {
+			defer wg.Done()
+			err := ipfs.Swarm().Connect(ctx, *peerInfo)
+			if err != nil {
+				panic(fmt.Errorf("failed to connect to %s: %s", peerInfo.ID, err))
+			}
+		}(peerInfo)
+	}
+	wg.Wait()
+	return nil
+}
+
+func stage(w http.ResponseWriter, req *http.Request) {
+	fmt.Fprintf(w, "%d", stageNow)
+}
+
+func next(w http.ResponseWriter, req *http.Request) {
+	sig <- struct{}{}
+}
+
+func connect(w http.ResponseWriter, req *http.Request) {
+	target := req.URL.Query().Get("target")
+	targetDecoded, err := b64.StdEncoding.DecodeString(target)
+	if err != nil {
+		return
+	}
+
+	target = string(targetDecoded)
+
+	targets = strings.Split(target, ",")
+}
+
+func extractTarGz(src, dest string) error {
+	tarFile, err := os.Open(filepath.Clean(src))
+	if err != nil {
+		return err
+	}
+	defer tarFile.Close()
+
+	gzipReader, err := gzip.NewReader(tarFile)
+	if err != nil {
+		return err
+	}
+	defer gzipReader.Close()
+
+	tarReader := tar.NewReader(gzipReader)
+
+	for {
+		header, err := tarReader.Next()
+
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+
+		// we created the tarball ourselves so it is safe
+		// #nosec G305
+		target := filepath.Join(dest, header.Name)
+
+		switch header.Typeflag {
+		case tar.TypeDir:
+			// it is expected to create directory with permission 755
+			// #nosec G301
+			if err := os.MkdirAll(target, 0755); err != nil {
+				return err
+			}
+		case tar.TypeReg:
+			outFile, err := os.Create(filepath.Clean(target))
+			if err != nil {
+				return err
+			}
+			defer outFile.Close()
+
+			// we created the tarball ourselves so it is safe
+			// #nosec G110
+			if _, err := io.Copy(outFile, tarReader); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}