How do I execute a command on a remote machine in a golang CLI?

Question

How do I execute a command on a remote machine in a golang CLI? I need to write a golang CLI that can SSH into a remote machine via a key and execute a shell command. Furthermor

Answer 1

You can run commands on a remote machine over SSH using the "golang.org/x/crypto/ssh" package.

Here is an example function demonstrating simple usage of running a single command on a remote machine and returning the output:

//e.g. output, err := remoteRun("root", "MY_IP", "PRIVATE_KEY", "ls")
func remoteRun(user string, addr string, privateKey string, cmd string) (string, error) {
    // privateKey could be read from a file, or retrieved from another storage
    // source, such as the Secret Service / GNOME Keyring
    key, err := ssh.ParsePrivateKey([]byte(privateKey))
    if err != nil {
        return "", err
    }
    // Authentication
    config := &ssh.ClientConfig{
        User: user,
        Auth: []ssh.AuthMethod{
            ssh.PublicKeys(key),
        },
        //alternatively, you could use a password
        /*
            Auth: []ssh.AuthMethod{
                ssh.Password("PASSWORD"),
            },
        */
    }
    // Connect
    client, err := ssh.Dial("tcp", net.JoinHostPort(addr, "22"), config)
    if err != nil {
        return "", err
    }
    // Create a session. It is one session per command.
    session, err := client.NewSession()
    if err != nil {
        return "", err
    }
    defer session.Close()
    var b bytes.Buffer  // import "bytes"
    session.Stdout = &b // get output
    // you can also pass what gets input to the stdin, allowing you to pipe
    // content from client to server
    //      session.Stdin = bytes.NewBufferString("My input")

    // Finally, run the command
    err = session.Run(cmd)
    return b.String(), err
}