plugeth/p2p/simulations/adapters/exec.go
Lewis Marshall 54aeb8e4c0 p2p/simulations: various stability fixes (#15198)
p2p/simulations: introduce dialBan

- Refactor simulations/network connection getters to support
  avoiding simultaneous dials between two peers If two peers dial
  simultaneously, the connection will be dropped to help avoid
  that, we essentially lock the connection object with a
  timestamp which serves as a ban on dialing for a period of time
  (dialBanTimeout).

- The connection getter InitConn can be wrapped and passed to the
  nodes via adapters.NodeConfig#Reachable field and then used by
  the respective services when they initiate connections. This
  massively stablise the emerging connectivity when running with
  hundreds of nodes bootstrapping a network.

p2p: add Inbound public method to p2p.Peer

p2p/simulations: Add server id to logs to support debugging
in-memory network simulations when multiple peers are logging.

p2p: SetupConn now returns error. The dialer checks the error and
only calls resolve if the actual TCP dial fails.
2017-12-01 12:49:04 +01:00

506 lines
14 KiB
Go

// Copyright 2017 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package adapters
import (
"bufio"
"context"
"crypto/ecdsa"
"encoding/json"
"errors"
"fmt"
"io"
"net"
"os"
"os/exec"
"os/signal"
"path/filepath"
"regexp"
"strings"
"sync"
"syscall"
"time"
"github.com/docker/docker/pkg/reexec"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/node"
"github.com/ethereum/go-ethereum/p2p"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/rpc"
"golang.org/x/net/websocket"
)
// ExecAdapter is a NodeAdapter which runs simulation nodes by executing the
// current binary as a child process.
//
// An init hook is used so that the child process executes the node services
// (rather than whataver the main() function would normally do), see the
// execP2PNode function for more information.
type ExecAdapter struct {
// BaseDir is the directory under which the data directories for each
// simulation node are created.
BaseDir string
nodes map[discover.NodeID]*ExecNode
}
// NewExecAdapter returns an ExecAdapter which stores node data in
// subdirectories of the given base directory
func NewExecAdapter(baseDir string) *ExecAdapter {
return &ExecAdapter{
BaseDir: baseDir,
nodes: make(map[discover.NodeID]*ExecNode),
}
}
// Name returns the name of the adapter for logging purposes
func (e *ExecAdapter) Name() string {
return "exec-adapter"
}
// NewNode returns a new ExecNode using the given config
func (e *ExecAdapter) NewNode(config *NodeConfig) (Node, error) {
if len(config.Services) == 0 {
return nil, errors.New("node must have at least one service")
}
for _, service := range config.Services {
if _, exists := serviceFuncs[service]; !exists {
return nil, fmt.Errorf("unknown node service %q", service)
}
}
// create the node directory using the first 12 characters of the ID
// as Unix socket paths cannot be longer than 256 characters
dir := filepath.Join(e.BaseDir, config.ID.String()[:12])
if err := os.Mkdir(dir, 0755); err != nil {
return nil, fmt.Errorf("error creating node directory: %s", err)
}
// generate the config
conf := &execNodeConfig{
Stack: node.DefaultConfig,
Node: config,
}
conf.Stack.DataDir = filepath.Join(dir, "data")
conf.Stack.WSHost = "127.0.0.1"
conf.Stack.WSPort = 0
conf.Stack.WSOrigins = []string{"*"}
conf.Stack.WSExposeAll = true
conf.Stack.P2P.EnableMsgEvents = false
conf.Stack.P2P.NoDiscovery = true
conf.Stack.P2P.NAT = nil
conf.Stack.NoUSB = true
// listen on a random localhost port (we'll get the actual port after
// starting the node through the RPC admin.nodeInfo method)
conf.Stack.P2P.ListenAddr = "127.0.0.1:0"
node := &ExecNode{
ID: config.ID,
Dir: dir,
Config: conf,
adapter: e,
}
node.newCmd = node.execCommand
e.nodes[node.ID] = node
return node, nil
}
// ExecNode starts a simulation node by exec'ing the current binary and
// running the configured services
type ExecNode struct {
ID discover.NodeID
Dir string
Config *execNodeConfig
Cmd *exec.Cmd
Info *p2p.NodeInfo
adapter *ExecAdapter
client *rpc.Client
wsAddr string
newCmd func() *exec.Cmd
key *ecdsa.PrivateKey
}
// Addr returns the node's enode URL
func (n *ExecNode) Addr() []byte {
if n.Info == nil {
return nil
}
return []byte(n.Info.Enode)
}
// Client returns an rpc.Client which can be used to communicate with the
// underlying services (it is set once the node has started)
func (n *ExecNode) Client() (*rpc.Client, error) {
return n.client, nil
}
// wsAddrPattern is a regex used to read the WebSocket address from the node's
// log
var wsAddrPattern = regexp.MustCompile(`ws://[\d.:]+`)
// Start exec's the node passing the ID and service as command line arguments
// and the node config encoded as JSON in the _P2P_NODE_CONFIG environment
// variable
func (n *ExecNode) Start(snapshots map[string][]byte) (err error) {
if n.Cmd != nil {
return errors.New("already started")
}
defer func() {
if err != nil {
log.Error("node failed to start", "err", err)
n.Stop()
}
}()
// encode a copy of the config containing the snapshot
confCopy := *n.Config
confCopy.Snapshots = snapshots
confCopy.PeerAddrs = make(map[string]string)
for id, node := range n.adapter.nodes {
confCopy.PeerAddrs[id.String()] = node.wsAddr
}
confData, err := json.Marshal(confCopy)
if err != nil {
return fmt.Errorf("error generating node config: %s", err)
}
// use a pipe for stderr so we can both copy the node's stderr to
// os.Stderr and read the WebSocket address from the logs
stderrR, stderrW := io.Pipe()
stderr := io.MultiWriter(os.Stderr, stderrW)
// start the node
cmd := n.newCmd()
cmd.Stdout = os.Stdout
cmd.Stderr = stderr
cmd.Env = append(os.Environ(), fmt.Sprintf("_P2P_NODE_CONFIG=%s", confData))
if err := cmd.Start(); err != nil {
return fmt.Errorf("error starting node: %s", err)
}
n.Cmd = cmd
// read the WebSocket address from the stderr logs
var wsAddr string
wsAddrC := make(chan string)
go func() {
s := bufio.NewScanner(stderrR)
for s.Scan() {
if strings.Contains(s.Text(), "WebSocket endpoint opened:") {
wsAddrC <- wsAddrPattern.FindString(s.Text())
}
}
}()
select {
case wsAddr = <-wsAddrC:
if wsAddr == "" {
return errors.New("failed to read WebSocket address from stderr")
}
case <-time.After(10 * time.Second):
return errors.New("timed out waiting for WebSocket address on stderr")
}
// create the RPC client and load the node info
ctx, cancel := context.WithTimeout(context.Background(), 10*time.Second)
defer cancel()
client, err := rpc.DialWebsocket(ctx, wsAddr, "")
if err != nil {
return fmt.Errorf("error dialing rpc websocket: %s", err)
}
var info p2p.NodeInfo
if err := client.CallContext(ctx, &info, "admin_nodeInfo"); err != nil {
return fmt.Errorf("error getting node info: %s", err)
}
n.client = client
n.wsAddr = wsAddr
n.Info = &info
return nil
}
// execCommand returns a command which runs the node locally by exec'ing
// the current binary but setting argv[0] to "p2p-node" so that the child
// runs execP2PNode
func (n *ExecNode) execCommand() *exec.Cmd {
return &exec.Cmd{
Path: reexec.Self(),
Args: []string{"p2p-node", strings.Join(n.Config.Node.Services, ","), n.ID.String()},
}
}
// Stop stops the node by first sending SIGTERM and then SIGKILL if the node
// doesn't stop within 5s
func (n *ExecNode) Stop() error {
if n.Cmd == nil {
return nil
}
defer func() {
n.Cmd = nil
}()
if n.client != nil {
n.client.Close()
n.client = nil
n.wsAddr = ""
n.Info = nil
}
if err := n.Cmd.Process.Signal(syscall.SIGTERM); err != nil {
return n.Cmd.Process.Kill()
}
waitErr := make(chan error)
go func() {
waitErr <- n.Cmd.Wait()
}()
select {
case err := <-waitErr:
return err
case <-time.After(5 * time.Second):
return n.Cmd.Process.Kill()
}
}
// NodeInfo returns information about the node
func (n *ExecNode) NodeInfo() *p2p.NodeInfo {
info := &p2p.NodeInfo{
ID: n.ID.String(),
}
if n.client != nil {
n.client.Call(&info, "admin_nodeInfo")
}
return info
}
// ServeRPC serves RPC requests over the given connection by dialling the
// node's WebSocket address and joining the two connections
func (n *ExecNode) ServeRPC(clientConn net.Conn) error {
conn, err := websocket.Dial(n.wsAddr, "", "http://localhost")
if err != nil {
return err
}
var wg sync.WaitGroup
wg.Add(2)
join := func(src, dst net.Conn) {
defer wg.Done()
io.Copy(dst, src)
// close the write end of the destination connection
if cw, ok := dst.(interface {
CloseWrite() error
}); ok {
cw.CloseWrite()
} else {
dst.Close()
}
}
go join(conn, clientConn)
go join(clientConn, conn)
wg.Wait()
return nil
}
// Snapshots creates snapshots of the services by calling the
// simulation_snapshot RPC method
func (n *ExecNode) Snapshots() (map[string][]byte, error) {
if n.client == nil {
return nil, errors.New("RPC not started")
}
var snapshots map[string][]byte
return snapshots, n.client.Call(&snapshots, "simulation_snapshot")
}
func init() {
// register a reexec function to start a devp2p node when the current
// binary is executed as "p2p-node"
reexec.Register("p2p-node", execP2PNode)
}
// execNodeConfig is used to serialize the node configuration so it can be
// passed to the child process as a JSON encoded environment variable
type execNodeConfig struct {
Stack node.Config `json:"stack"`
Node *NodeConfig `json:"node"`
Snapshots map[string][]byte `json:"snapshots,omitempty"`
PeerAddrs map[string]string `json:"peer_addrs,omitempty"`
}
// execP2PNode starts a devp2p node when the current binary is executed with
// argv[0] being "p2p-node", reading the service / ID from argv[1] / argv[2]
// and the node config from the _P2P_NODE_CONFIG environment variable
func execP2PNode() {
glogger := log.NewGlogHandler(log.StreamHandler(os.Stderr, log.LogfmtFormat()))
glogger.Verbosity(log.LvlInfo)
log.Root().SetHandler(glogger)
// read the services from argv
serviceNames := strings.Split(os.Args[1], ",")
// decode the config
confEnv := os.Getenv("_P2P_NODE_CONFIG")
if confEnv == "" {
log.Crit("missing _P2P_NODE_CONFIG")
}
var conf execNodeConfig
if err := json.Unmarshal([]byte(confEnv), &conf); err != nil {
log.Crit("error decoding _P2P_NODE_CONFIG", "err", err)
}
conf.Stack.P2P.PrivateKey = conf.Node.PrivateKey
conf.Stack.Logger = log.New("node.id", conf.Node.ID.String())
// use explicit IP address in ListenAddr so that Enode URL is usable
externalIP := func() string {
addrs, err := net.InterfaceAddrs()
if err != nil {
log.Crit("error getting IP address", "err", err)
}
for _, addr := range addrs {
if ip, ok := addr.(*net.IPNet); ok && !ip.IP.IsLoopback() {
return ip.IP.String()
}
}
log.Crit("unable to determine explicit IP address")
return ""
}
if strings.HasPrefix(conf.Stack.P2P.ListenAddr, ":") {
conf.Stack.P2P.ListenAddr = externalIP() + conf.Stack.P2P.ListenAddr
}
if conf.Stack.WSHost == "0.0.0.0" {
conf.Stack.WSHost = externalIP()
}
// initialize the devp2p stack
stack, err := node.New(&conf.Stack)
if err != nil {
log.Crit("error creating node stack", "err", err)
}
// register the services, collecting them into a map so we can wrap
// them in a snapshot service
services := make(map[string]node.Service, len(serviceNames))
for _, name := range serviceNames {
serviceFunc, exists := serviceFuncs[name]
if !exists {
log.Crit("unknown node service", "name", name)
}
constructor := func(nodeCtx *node.ServiceContext) (node.Service, error) {
ctx := &ServiceContext{
RPCDialer: &wsRPCDialer{addrs: conf.PeerAddrs},
NodeContext: nodeCtx,
Config: conf.Node,
}
if conf.Snapshots != nil {
ctx.Snapshot = conf.Snapshots[name]
}
service, err := serviceFunc(ctx)
if err != nil {
return nil, err
}
services[name] = service
return service, nil
}
if err := stack.Register(constructor); err != nil {
log.Crit("error starting service", "name", name, "err", err)
}
}
// register the snapshot service
if err := stack.Register(func(ctx *node.ServiceContext) (node.Service, error) {
return &snapshotService{services}, nil
}); err != nil {
log.Crit("error starting snapshot service", "err", err)
}
// start the stack
if err := stack.Start(); err != nil {
log.Crit("error stating node stack", "err", err)
}
// stop the stack if we get a SIGTERM signal
go func() {
sigc := make(chan os.Signal, 1)
signal.Notify(sigc, syscall.SIGTERM)
defer signal.Stop(sigc)
<-sigc
log.Info("Received SIGTERM, shutting down...")
stack.Stop()
}()
// wait for the stack to exit
stack.Wait()
}
// snapshotService is a node.Service which wraps a list of services and
// exposes an API to generate a snapshot of those services
type snapshotService struct {
services map[string]node.Service
}
func (s *snapshotService) APIs() []rpc.API {
return []rpc.API{{
Namespace: "simulation",
Version: "1.0",
Service: SnapshotAPI{s.services},
}}
}
func (s *snapshotService) Protocols() []p2p.Protocol {
return nil
}
func (s *snapshotService) Start(*p2p.Server) error {
return nil
}
func (s *snapshotService) Stop() error {
return nil
}
// SnapshotAPI provides an RPC method to create snapshots of services
type SnapshotAPI struct {
services map[string]node.Service
}
func (api SnapshotAPI) Snapshot() (map[string][]byte, error) {
snapshots := make(map[string][]byte)
for name, service := range api.services {
if s, ok := service.(interface {
Snapshot() ([]byte, error)
}); ok {
snap, err := s.Snapshot()
if err != nil {
return nil, err
}
snapshots[name] = snap
}
}
return snapshots, nil
}
type wsRPCDialer struct {
addrs map[string]string
}
// DialRPC implements the RPCDialer interface by creating a WebSocket RPC
// client of the given node
func (w *wsRPCDialer) DialRPC(id discover.NodeID) (*rpc.Client, error) {
addr, ok := w.addrs[id.String()]
if !ok {
return nil, fmt.Errorf("unknown node: %s", id)
}
return rpc.DialWebsocket(context.Background(), addr, "http://localhost")
}