Documentation
¶
Overview ¶
Package tunnel provides APIs to create SSH tunnels to perform local port forwarding, leveraging the SSH configuration file (e.g. $HOME/.ssh/config) to find specific attributes of the target ssh server like user name, port, host name and key when not provided.
SSH Config File Support ¶
The module looks for the ssh config file stored on $HOME/.ssh/config only. There is no fallback support to try to use /etc/ssh/config.
The current API supports the following ssh config file options:
Host Hostname User Port IdentityKey
For more information about SSH Local Port Forwarding, please visit: https://www.ssh.com/ssh/tunneling/example#sec-Local-Forwarding
For more information about SSH Config File, please visit: https://www.ssh.com/ssh/config/
Example ¶
This example shows the basic usage of the package: define both the local and remote endpoints, the ssh server and then start the tunnel that will exchange data from the local address to the remote address through the established ssh channel.
package main
import (
"log"
"github.com/davrodpin/mole/tunnel"
)
func main() {
local := "127.0.0.1:8080"
remote := "user@example.com:22"
// Initialize the SSH Server configuration providing all values so
// tunnel.NewServer will not try to lookup any value using $HOME/.ssh/config
server, err := tunnel.NewServer("user", "172.17.0.20:2222", "/home/user/.ssh/key")
if err != nil {
log.Fatalf("error processing server options: %v\n", err)
}
t := tunnel.New(local, server, remote)
// Start the tunnel
err = t.Start()
if err != nil {
log.Fatalf("error starting tunnel: %v\n", err)
}
}
Output:
Index ¶
Examples ¶
Constants ¶
const (
HostMissing = "server host has to be provided as part of the server address"
)
Variables ¶
This section is empty.
Functions ¶
This section is empty.
Types ¶
type LocalForward ¶ added in v0.3.0
LocalForward represents a LocalForward configuration for SSHHost.
func (LocalForward) String ¶ added in v0.3.0
func (f LocalForward) String() string
String returns a string representation of LocalForward.
type PemKey ¶ added in v0.3.0
type PemKey struct {
// Data holds the data for a PEM private key
Data []byte
// contains filtered or unexported fields
}
PemKey holds data related to PEM keys
func (*PemKey) HandlePassphrase ¶ added in v0.3.0
HandlePassphrase securely records a passphrase given by a callback to the memory.
func (PemKey) IsEncrypted ¶ added in v0.3.0
IsEncrypted inspects the key data block to tell if it is whether encrypted or not.
type PemKeyParser ¶ added in v0.3.0
type PemKeyParser interface {
// Parse returns a key signer to create signatures that verify against a
// public key.
Parse() (*ssh.Signer, error)
}
PemKeyParser translates pem keys to a signature signer.
type SSHConfigFile ¶ added in v0.3.0
type SSHConfigFile struct {
// contains filtered or unexported fields
}
SSHConfigFile finds specific attributes of a ssh server configured on a ssh config file.
func NewSSHConfigFile ¶ added in v0.3.0
func NewSSHConfigFile() (*SSHConfigFile, error)
NewSSHConfigFile creates a new instance of SSHConfigFile based on the ssh config file from $HOME/.ssh/config.
func (SSHConfigFile) Get ¶ added in v0.3.0
func (r SSHConfigFile) Get(host string) *SSHHost
Get consults a ssh config file to extract some ssh server attributes from it, returning a SSHHost. Any attribute which its value is an empty string is an attribute that could not be found in the ssh config file.
type SSHHost ¶ added in v0.3.0
type SSHHost struct {
Hostname string
Port string
User string
Key string
LocalForward *LocalForward
}
SSHHost represents a host configuration extracted from a ssh config file.
type Server ¶
type Server struct {
Name string
Address string
User string
Key *PemKey
// Insecure is a flag to indicate if the host keys should be validated.
Insecure bool
}
Server holds the SSH Server attributes used for the client to connect to it.
type Tunnel ¶
type Tunnel struct {
// Ready tells when the Tunnel is ready to accept connections
Ready chan bool
// contains filtered or unexported fields
}
Tunnel represents the ssh tunnel used to forward a local connection to a a remote endpoint through a ssh server.
Source Files