Accept identityfile in the server string with fallback to id_rsa

This commit is contained in:
Nilesh T 2018-08-15 16:42:22 +05:30
parent e598ae5c01
commit 81e55693fc
2 changed files with 41 additions and 20 deletions

View file

@ -45,20 +45,34 @@ type sshClient struct {
// dial establishes an SSH connection to a remote node using the current user and // dial establishes an SSH connection to a remote node using the current user and
// the user's configured private RSA key. If that fails, password authentication // the user's configured private RSA key. If that fails, password authentication
// is fallen back to. The caller may override the login user via user@server:port. // is fallen back to. server can be a string like user:identity@server:port.
func dial(server string, pubkey []byte) (*sshClient, error) { func dial(server string, pubkey []byte) (*sshClient, error) {
// Figure out a label for the server and a logger // Figure out username, identity_file, hostname and port
label := server
if strings.Contains(label, ":") {
label = label[:strings.Index(label, ":")]
}
login := "" login := ""
identity_file := "id_rsa" // default
hostport := server
hostname := ""
if strings.Contains(server, "@") { if strings.Contains(server, "@") {
login = label[:strings.Index(label, "@")] prefix := server[:strings.Index(server, "@")]
label = label[strings.Index(label, "@")+1:] if strings.Contains(prefix, ":") {
server = server[strings.Index(server, "@")+1:] login = prefix[:strings.Index(prefix, ":")]
identity_file = prefix[strings.Index(prefix, ":")+1:]
} else {
login = prefix
}
hostport = server[strings.Index(server, "@")+1:]
} }
logger := log.New("server", label)
// parse hostname and port
if strings.Contains(hostport, ":") {
hostname = hostport[:strings.Index(hostport, ":")]
} else {
hostname = hostport
hostport += ":22"
}
logger := log.New("server", server)
logger.Debug("Attempting to establish SSH connection") logger.Debug("Attempting to establish SSH connection")
user, err := user.Current() user, err := user.Current()
@ -68,10 +82,11 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
if login == "" { if login == "" {
login = user.Username login = user.Username
} }
fmt.Printf("parsed %s:%s@%s\nhn=%s", login, identity_file, hostport, hostname)
// Configure the supported authentication methods (private key and password) // Configure the supported authentication methods (private key and password)
var auths []ssh.AuthMethod var auths []ssh.AuthMethod
path := filepath.Join(user.HomeDir, ".ssh", "id_rsa") path := filepath.Join(user.HomeDir, ".ssh", identity_file)
if buf, err := ioutil.ReadFile(path); err != nil { if buf, err := ioutil.ReadFile(path); err != nil {
log.Warn("No SSH key, falling back to passwords", "path", path, "err", err) log.Warn("No SSH key, falling back to passwords", "path", path, "err", err)
} else { } else {
@ -101,7 +116,7 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
return string(blob), err return string(blob), err
})) }))
// Resolve the IP address of the remote server // Resolve the IP address of the remote server
addr, err := net.LookupHost(label) addr, err := net.LookupHost(hostname)
if err != nil { if err != nil {
return nil, err return nil, err
} }
@ -110,9 +125,6 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
} }
// Try to dial in to the remote server // Try to dial in to the remote server
logger.Trace("Dialing remote SSH server", "user", login) logger.Trace("Dialing remote SSH server", "user", login)
if !strings.Contains(server, ":") {
server += ":22"
}
keycheck := func(hostname string, remote net.Addr, key ssh.PublicKey) error { keycheck := func(hostname string, remote net.Addr, key ssh.PublicKey) error {
// If no public key is known for SSH, ask the user to confirm // If no public key is known for SSH, ask the user to confirm
if pubkey == nil { if pubkey == nil {
@ -139,13 +151,13 @@ func dial(server string, pubkey []byte) (*sshClient, error) {
// We have a mismatch, forbid connecting // We have a mismatch, forbid connecting
return errors.New("ssh key mismatch, readd the machine to update") return errors.New("ssh key mismatch, readd the machine to update")
} }
client, err := ssh.Dial("tcp", server, &ssh.ClientConfig{User: login, Auth: auths, HostKeyCallback: keycheck}) client, err := ssh.Dial("tcp", hostport, &ssh.ClientConfig{User: login, Auth: auths, HostKeyCallback: keycheck})
if err != nil { if err != nil {
return nil, err return nil, err
} }
// Connection established, return our utility wrapper // Connection established, return our utility wrapper
c := &sshClient{ c := &sshClient{
server: label, server: hostport,
address: addr[0], address: addr[0],
pubkey: pubkey, pubkey: pubkey,
client: client, client: client,

View file

@ -18,6 +18,7 @@ package main
import ( import (
"fmt" "fmt"
"os/user"
"strings" "strings"
"github.com/ethereum/go-ethereum/log" "github.com/ethereum/go-ethereum/log"
@ -62,14 +63,22 @@ func (w *wizard) manageServers() {
} }
} }
// makeServer reads a single line from stdin and interprets it as a hostname to // makeServer reads a single line from stdin and interprets it as
// connect to. It tries to establish a new SSH session and also executing some // username:identity@hostname to connect to.
// It tries to establish a new SSH session and also executing some
// baseline validations. // baseline validations.
// //
// If connection succeeds, the server is added to the wizards configs! // If connection succeeds, the server is added to the wizards configs!
func (w *wizard) makeServer() string { func (w *wizard) makeServer() string {
login := ""
user, err := user.Current()
if err == nil {
login = user.Username
}
fmt.Println() fmt.Println()
fmt.Println("Please enter remote server's address:") fmt.Println("Please enter remote server (username:identity@hostname:port)")
fmt.Printf("If not given, will use username = %s, identity = id_rsa\n", login)
// Read and dial the server to ensure docker is present // Read and dial the server to ensure docker is present
input := w.readString() input := w.readString()