feat: M6 cluster binary registry + peer exchange (stage A)

This commit is contained in:
2026-08-17 17:53:07 +08:00
parent 467c7124ab
commit 79e0b3da79
3 changed files with 391 additions and 5 deletions

View File

@ -0,0 +1,313 @@
// Package cluster implements peer-to-peer distribution of the frpc binary and
// an in-memory node registry for the cluster. Binary exchange is preferred
// between cluster members; the external GitHub URL is only a fallback. A new
// member joining asks its neighbors to transmit the binary automatically.
package cluster
import (
"archive/tar"
"bytes"
"compress/gzip"
"context"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"net/http"
"os"
"os/exec"
"path/filepath"
"runtime"
"sort"
"strings"
"time"
)
// PeerTarget identifies a cluster node that can serve binaries.
type PeerTarget struct {
Addr string // host:port of the peer's frpc binary endpoint
User string
Pass string
}
// NodeInfo is exchanged during discovery: each node reports which frpc
// versions it has cached.
type NodeInfo struct {
ID string `json:"id"`
Addr string `json:"addr"`
Version string `json:"version,omitempty"`
Cache []string `json:"cache,omitempty"`
SeenAt int64 `json:"seenAt"`
}
// Registry tracks peers and the locally cached frpc binaries.
type Registry struct {
BinDir string
mu chan struct{} // simple mutex
peers map[string]*PeerTarget
nodeInf map[string]*NodeInfo
}
// NewRegistry builds a Registry rooted at binDir (where frpc-<version> dirs live).
func NewRegistry(binDir string) *Registry {
return &Registry{
BinDir: binDir,
mu: make(chan struct{}, 1),
peers: map[string]*PeerTarget{},
nodeInf: map[string]*NodeInfo{},
}
}
func (r *Registry) lock() { r.mu <- struct{}{} }
func (r *Registry) unlock() { <-r.mu }
// platformName mirrors install.platformName (kept local to avoid import cycle).
func platformName() string {
arch := runtime.GOARCH
if arch == "x86_64" {
arch = "amd64"
}
return runtime.GOOS + "_" + arch
}
// CachedVersions lists frpc versions present under binDir as frpc-<version>.
func (r *Registry) CachedVersions() []string {
entries, err := os.ReadDir(r.BinDir)
if err != nil {
return nil
}
var out []string
for _, e := range entries {
if !e.IsDir() || !strings.HasPrefix(e.Name(), "frpc-") {
continue
}
out = append(out, strings.TrimPrefix(e.Name(), "frpc-"))
}
sort.Strings(out)
return out
}
// HasVersion reports whether a version is both cached and has a runnable frpc.
func (r *Registry) HasVersion(version string) bool {
version = strings.TrimPrefix(version, "v")
p := filepath.Join(r.BinDir, "frpc-"+version, "frpc")
info, err := os.Stat(p)
return err == nil && !info.IsDir() && (info.Mode()&0o111) != 0
}
// BinaryPath returns the local file path for a cached version.
func (r *Registry) BinaryPath(version string) string {
return filepath.Join(r.BinDir, "frpc-"+strings.TrimPrefix(version, "v"), "frpc")
}
// Provide serves a cached binary to a peer. Returns the file path and a
// SHA-256 checksum for verification.
func (r *Registry) Provide(version string) (path, checksum string, err error) {
version = strings.TrimPrefix(version, "v")
p := r.BinaryPath(version)
info, err := os.Stat(p)
if err != nil || info.IsDir() {
return "", "", fmt.Errorf("version %s not cached locally", version)
}
h := sha256.New()
f, err := os.Open(p)
if err != nil {
return "", "", err
}
_, copyErr := io.Copy(h, f)
f.Close()
if copyErr != nil {
return "", "", copyErr
}
return p, hex.EncodeToString(h.Sum(nil)), nil
}
// RegisterPeer remembers a reachable peer so binary exchange can prefer it.
func (r *Registry) RegisterPeer(id, addr, user, pass string) {
r.lock()
defer r.unlock()
r.peers[id] = &PeerTarget{Addr: addr, User: user, Pass: pass}
}
// UpdateNodeInfo stores a discovered node's cached versions.
func (r *Registry) UpdateNodeInfo(ni *NodeInfo) {
r.lock()
defer r.unlock()
ni.SeenAt = time.Now().Unix()
r.nodeInf[ni.ID] = &NodeInfo{ID: ni.ID, Addr: ni.Addr, Version: ni.Version, Cache: append([]string(nil), ni.Cache...), SeenAt: ni.SeenAt}
}
// PeerList returns the currently registered peers (deep copy).
func (r *Registry) PeerList() []*PeerTarget {
r.lock()
defer r.unlock()
out := make([]*PeerTarget, 0, len(r.peers))
for _, p := range r.peers {
out = append(out, &PeerTarget{Addr: p.Addr, User: p.User, Pass: p.Pass})
}
return out
}
// NodeList returns the discovered nodes (deep copies) including cached versions.
func (r *Registry) NodeList() []NodeInfo {
r.lock()
defer r.unlock()
out := make([]NodeInfo, 0, len(r.nodeInf))
for _, n := range r.nodeInf {
out = append(out, NodeInfo{
ID: n.ID, Addr: n.Addr, Version: n.Version,
Cache: append([]string(nil), n.Cache...), SeenAt: n.SeenAt,
})
}
return out
}
// fetchFromPeer downloads the frpc binary for a version from one peer over
// HTTP GET /frpc/{version}. Basic Auth is used; the body is capped and its
// SHA-256 must match the peer-provided checksum (defense against corruption).
func fetchFromPeer(ctx context.Context, peer *PeerTarget, version, wantChecksum string) ([]byte, error) {
url := fmt.Sprintf("http://%s/frpc/%s", peer.Addr, strings.TrimPrefix(version, "v"))
req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
if err != nil {
return nil, err
}
if peer.User != "" || peer.Pass != "" {
req.SetBasicAuth(peer.User, peer.Pass)
}
cli := &http.Client{Timeout: 30 * time.Second}
resp, err := cli.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
_, _ = io.Copy(io.Discard, resp.Body)
return nil, fmt.Errorf("peer GET %s -> HTTP %d", url, resp.StatusCode)
}
data, err := io.ReadAll(io.LimitReader(resp.Body, 256<<20))
if err != nil {
return nil, err
}
if wantChecksum != "" {
sum := sha256.Sum256(data)
got := hex.EncodeToString(sum[:])
if !strings.EqualFold(got, wantChecksum) {
return nil, fmt.Errorf("peer binary checksum mismatch: got %s want %s", got, wantChecksum)
}
}
return data, nil
}
// githubURL builds the official GitHub release download URL for a version.
func githubURL(version string) string {
ver := strings.TrimPrefix(version, "v")
return fmt.Sprintf("https://github.com/fatedier/frp/releases/download/v%s/frp_%s_%s.tar.gz", ver, ver, platformName())
}
// fetchFromURL downloads the frpc *release tarball* from GitHub and extracts
// the frpc binary (same shape as install.Install). Returns extracted bytes.
func fetchFromURL(ctx context.Context, version string) ([]byte, error) {
url := githubURL(version)
req, err := http.NewRequestWithContext(ctx, http.MethodGet, url, nil)
if err != nil {
return nil, err
}
cli := &http.Client{Timeout: 120 * time.Second}
resp, err := cli.Do(req)
if err != nil {
return nil, err
}
defer resp.Body.Close()
if resp.StatusCode != http.StatusOK {
_, _ = io.Copy(io.Discard, resp.Body)
return nil, fmt.Errorf("URL %s -> HTTP %d", url, resp.StatusCode)
}
tarGz, err := io.ReadAll(io.LimitReader(resp.Body, 256<<20))
if err != nil {
return nil, err
}
return extractFrpcBytes(tarGz)
}
// EnsureVersion makes sure a given frpc version is cached locally. It follows
// the distribution priority: local cache -> cluster peers -> external URL.
func (r *Registry) EnsureVersion(ctx context.Context, version string) (string, error) {
version = strings.TrimPrefix(version, "v")
if r.HasVersion(version) {
return r.BinaryPath(version), nil
}
// 1) Try peers first (cluster-internal exchange is preferred).
for _, peer := range r.PeerList() {
data, err := fetchFromPeer(ctx, peer, version, "")
if err != nil {
continue
}
if err := r.storeBinary(version, data); err != nil {
continue
}
if r.HasVersion(version) {
return r.BinaryPath(version), nil
}
}
// 2) Fall back to the external GitHub URL.
if data, err := fetchFromURL(ctx, version); err == nil {
if err := r.storeBinary(version, data); err == nil && r.HasVersion(version) {
return r.BinaryPath(version), nil
}
}
return "", fmt.Errorf("unable to obtain frpc %s from cache, peers, or URL", version)
}
// storeBinary persists freshly fetched frpc bytes under binDir/frpc-<version>
// and verifies the binary runs with --version.
func (r *Registry) storeBinary(version string, data []byte) error {
if err := os.MkdirAll(r.BinDir, 0o755); err != nil {
return err
}
version = strings.TrimPrefix(version, "v")
dir := filepath.Join(r.BinDir, "frpc-"+version)
if err := os.MkdirAll(dir, 0o755); err != nil {
return err
}
bin := filepath.Join(dir, "frpc")
if err := os.WriteFile(bin, data, 0o755); err != nil {
return err
}
if out, err := exec.Command(bin, "--version").CombinedOutput(); err != nil {
_ = os.RemoveAll(dir)
return fmt.Errorf("peer-provided frpc failed --version: %v (%s)", err, bytes.TrimSpace(out))
}
return nil
}
// extractFrpcBytes extracts the frpc executable bytes from a GitHub release
// tarball (frp_<v>_<platform>.tar.gz). Only the top-level frpc is taken.
func extractFrpcBytes(tarGz []byte) ([]byte, error) {
gzr, err := gzip.NewReader(bytes.NewReader(tarGz))
if err != nil {
return nil, err
}
defer gzr.Close()
tr := tar.NewReader(gzr)
for {
hdr, err := tr.Next()
if err == io.EOF {
return nil, fmt.Errorf("frpc not found in archive")
}
if err != nil {
return nil, err
}
name := filepath.Base(hdr.Name)
if hdr.Typeflag == tar.TypeReg && name == "frpc" {
data, err := io.ReadAll(io.LimitReader(tr, 256<<20))
if err != nil {
return nil, err
}
return data, nil
}
}
}