cmd/puppeth: your Ethereum private network manager (#13854)

1 files changed, 195 insertions, 0 deletions

diff --git a/cmd/puppeth/ssh.go b/cmd/puppeth/ssh.go
new file mode 100644
index 000000000..34fbc566d
--- /dev/null
+++ b/cmd/puppeth/ssh.go
@@ -0,0 +1,195 @@
+// Copyright 2017 The go-ethereum Authors
+// This file is part of go-ethereum.
+//
+// go-ethereum is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// go-ethereum 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
+
+package main
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os"
+	"os/user"
+	"path/filepath"
+	"strings"
+	"syscall"
+
+	"github.com/ethereum/go-ethereum/log"
+	"golang.org/x/crypto/ssh"
+	"golang.org/x/crypto/ssh/terminal"
+)
+
+// sshClient is a small wrapper around Go's SSH client with a few utility methods
+// implemented on top.
+type sshClient struct {
+	server  string // Server name or IP without port number
+	address string // IP address of the remote server
+	client  *ssh.Client
+	logger  log.Logger
+}
+
+// dial establishes an SSH connection to a remote node using the current user and
+// the user's configured private RSA key.
+func dial(server string) (*sshClient, error) {
+	// Figure out a label for the server and a logger
+	label := server
+	if strings.Contains(label, ":") {
+		label = label[:strings.Index(label, ":")]
+	}
+	logger := log.New("server", label)
+	logger.Debug("Attempting to establish SSH connection")
+
+	user, err := user.Current()
+	if err != nil {
+		return nil, err
+	}
+	// Configure the supported authentication methods (private key and password)
+	var auths []ssh.AuthMethod
+
+	path := filepath.Join(user.HomeDir, ".ssh", "id_rsa")
+	if buf, err := ioutil.ReadFile(path); err != nil {
+		log.Warn("No SSH key, falling back to passwords", "path", path, "err", err)
+	} else {
+		key, err := ssh.ParsePrivateKey(buf)
+		if err != nil {
+			log.Warn("Bad SSH key, falling back to passwords", "path", path, "err", err)
+		} else {
+			auths = append(auths, ssh.PublicKeys(key))
+		}
+	}
+	auths = append(auths, ssh.PasswordCallback(func() (string, error) {
+		fmt.Printf("What's the login password for %s at %s? (won't be echoed)\n> ", user.Username, server)
+		blob, err := terminal.ReadPassword(int(syscall.Stdin))
+
+		fmt.Println()
+		return string(blob), err
+	}))
+	// Resolve the IP address of the remote server
+	addr, err := net.LookupHost(label)
+	if err != nil {
+		return nil, err
+	}
+	if len(addr) == 0 {
+		return nil, errors.New("no IPs associated with domain")
+	}
+	// Try to dial in to the remote server
+	logger.Trace("Dialing remote SSH server", "user", user.Username, "key", path)
+	if !strings.Contains(server, ":") {
+		server += ":22"
+	}
+	client, err := ssh.Dial("tcp", server, &ssh.ClientConfig{User: user.Username, Auth: auths})
+	if err != nil {
+		return nil, err
+	}
+	// Connection established, return our utility wrapper
+	c := &sshClient{
+		server:  label,
+		address: addr[0],
+		client:  client,
+		logger:  logger,
+	}
+	if err := c.init(); err != nil {
+		client.Close()
+		return nil, err
+	}
+	return c, nil
+}
+
+// init runs some initialization commands on the remote server to ensure it's
+// capable of acting as puppeth target.
+func (client *sshClient) init() error {
+	client.logger.Debug("Verifying if docker is available")
+	if out, err := client.Run("docker version"); err != nil {
+		if len(out) == 0 {
+			return err
+		}
+		return fmt.Errorf("docker configured incorrectly: %s", out)
+	}
+	client.logger.Debug("Verifying if docker-compose is available")
+	if out, err := client.Run("docker-compose version"); err != nil {
+		if len(out) == 0 {
+			return err
+		}
+		return fmt.Errorf("docker-compose configured incorrectly: %s", out)
+	}
+	return nil
+}
+
+// Close terminates the connection to an SSH server.
+func (client *sshClient) Close() error {
+	return client.client.Close()
+}
+
+// Run executes a command on the remote server and returns the combined output
+// along with any error status.
+func (client *sshClient) Run(cmd string) ([]byte, error) {
+	// Establish a single command session
+	session, err := client.client.NewSession()
+	if err != nil {
+		return nil, err
+	}
+	defer session.Close()
+
+	// Execute the command and return any output
+	client.logger.Trace("Running command on remote server", "cmd", cmd)
+	return session.CombinedOutput(cmd)
+}
+
+// Stream executes a command on the remote server and streams all outputs into
+// the local stdout and stderr streams.
+func (client *sshClient) Stream(cmd string) error {
+	// Establish a single command session
+	session, err := client.client.NewSession()
+	if err != nil {
+		return err
+	}
+	defer session.Close()
+
+	session.Stdout = os.Stdout
+	session.Stderr = os.Stderr
+
+	// Execute the command and return any output
+	client.logger.Trace("Streaming command on remote server", "cmd", cmd)
+	return session.Run(cmd)
+}
+
+// Upload copied the set of files to a remote server via SCP, creating any non-
+// existing folder in te mean time.
+func (client *sshClient) Upload(files map[string][]byte) ([]byte, error) {
+	// Establish a single command session
+	session, err := client.client.NewSession()
+	if err != nil {
+		return nil, err
+	}
+	defer session.Close()
+
+	// Create a goroutine that streams the SCP content
+	go func() {
+		out, _ := session.StdinPipe()
+		defer out.Close()
+
+		for file, content := range files {
+			client.logger.Trace("Uploading file to server", "file", file, "bytes", len(content))
+
+			fmt.Fprintln(out, "D0755", 0, filepath.Dir(file))             // Ensure the folder exists
+			fmt.Fprintln(out, "C0644", len(content), filepath.Base(file)) // Create the actual file
+			out.Write(content)                                            // Stream the data content
+			fmt.Fprint(out, "\x00")                                       // Transfer end with \x00
+			fmt.Fprintln(out, "E")                                        // Leave directory (simpler)
+		}
+	}()
+	return session.CombinedOutput("/usr/bin/scp -v -tr ./")
+}