DockerCLI/cli/connhelper/ssh/ssh.go

71 lines
1.5 KiB
Go

// Package ssh provides the connection helper for ssh:// URL.
// Requires Docker 18.09 or later on the remote host.
package ssh
import (
"net/url"
"github.com/pkg/errors"
)
// New returns cmd and its args
func New(daemonURL string) (string, []string, error) {
sp, err := parseSSHURL(daemonURL)
if err != nil {
return "", nil, err
}
return "ssh", append(sp.Args(), []string{"--", "docker", "system", "dial-stdio"}...), nil
}
func parseSSHURL(daemonURL string) (*sshSpec, error) {
u, err := url.Parse(daemonURL)
if err != nil {
return nil, err
}
if u.Scheme != "ssh" {
return nil, errors.Errorf("expected scheme ssh, got %s", u.Scheme)
}
var sp sshSpec
if u.User != nil {
sp.user = u.User.Username()
if _, ok := u.User.Password(); ok {
return nil, errors.New("ssh helper does not accept plain-text password")
}
}
sp.host = u.Hostname()
if sp.host == "" {
return nil, errors.Errorf("host is not specified")
}
sp.port = u.Port()
if u.Path != "" {
return nil, errors.Errorf("extra path: %s", u.Path)
}
if u.RawQuery != "" {
return nil, errors.Errorf("extra query: %s", u.RawQuery)
}
if u.Fragment != "" {
return nil, errors.Errorf("extra fragment: %s", u.Fragment)
}
return &sp, err
}
type sshSpec struct {
user string
host string
port string
}
func (sp *sshSpec) Args() []string {
var args []string
if sp.user != "" {
args = append(args, "-l", sp.user)
}
if sp.port != "" {
args = append(args, "-p", sp.port)
}
args = append(args, sp.host)
return args
}