SSH Client
To create an SSH client program in Go, you need to create a few files: main.go for the main logic and optionally, a client.go file for the client functionality. Here is a step-by-step guide:
Step 1: Initialize the Go Module
First, create a new directory for your project and initialize the Go module.
mkdir sshclient
cd sshclient
go mod init github.com/username/sshclient
Step 2: Create the client.go File
Create a client.go file to handle the SSH client functionality.
// client.go
package main
import (
"golang.org/x/crypto/ssh"
"io/ioutil"
"log"
"os"
)
// SSHClient represents an SSH client.
type SSHClient struct {
client *ssh.Client
}
// NewSSHClient creates a new SSH client.
func NewSSHClient(user, password, host string, port int) (*SSHClient, error) {
config := &ssh.ClientConfig{
User: user,
Auth: []ssh.AuthMethod{
ssh.Password(password),
},
HostKeyCallback: ssh.InsecureIgnoreHostKey(),
}
address := fmt.Sprintf("%s:%d", host, port)
client, err := ssh.Dial("tcp", address, config)
if err != nil {
return nil, err
}
return &SSHClient{client: client}, nil
}
// RunCommand runs a command on the remote SSH server.
func (s *SSHClient) RunCommand(cmd string) (string, error) {
session, err := s.client.NewSession()
if err != nil {
return "", err
}
defer session.Close()
output, err := session.CombinedOutput(cmd)
if err != nil {
return "", err
}
return string(output), nil
}
// Close closes the SSH client connection.
func (s *SSHClient) Close() error {
return s.client.Close()
}
Step 3: Create the main.go File
Create a main.go file to use the client functionality.
// main.go
package main
import (
"fmt"
"os"
"strconv"
)
func main() {
if len(os.Args) != 6 {
fmt.Println("Usage: sshclient <user> <password> <host> <port> <command>")
os.Exit(1)
}
user := os.Args[1]
password := os.Args[2]
host := os.Args[3]
port, err := strconv.Atoi(os.Args[4])
if err != nil {
fmt.Printf("Invalid port: %v\n", err)
os.Exit(1)
}
command := os.Args[5]
client, err := NewSSHClient(user, password, host, port)
if err != nil {
fmt.Printf("Failed to create SSH client: %v\n", err)
os.Exit(1)
}
defer client.Close()
output, err := client.RunCommand(command)
if err != nil {
fmt.Printf("Failed to run command: %v\n", err)
os.Exit(1)
}
fmt.Println("Command output:", output)
}
Step 4: Run the Program
Run the program using the go run command.
go run main.go username password host 22 "ls -l"
This will connect to the SSH server at the specified host and port, run the given command, and print the output.
Last modified: 19 December 2024