Advanced SSH config

Enhances ssh_config file capabilities

NOTE: This program is called by ProxyCommand from lib-ssh.

It works transparently with :

ssh
scp
rsync
git
and even desktop applications depending on lib-ssh (for instance Tower, Atom.io, SSH Tunnel Manager)

The .ssh/config file is automatically generated, you need to update .ssh/config.advanced file instead; With new features and a better regex engine for the hostnames.

Usage

$ assh --help
Usage: assh [OPTIONS] COMMAND [arg...]

Commands:
  build                 Build .ssh/config based on .ssh/config.advanced
  connect <host>        Open a connection to <host>
  info <host>           Print connection informations
  init                  Build a .ssh/config.advanced file based on .ssh/config
  generate-etc-hosts    Print a /etc/hosts file of .ssh/config.advanced
  stats                 Print statistics

Options:
  --version             show program's version number and exit
  -h, --help            show this help message and exit
  -p PORT, --port=PORT  SSH port
  -c CONFIG_FILE, --config=CONFIG_FILE
                        ssh_config file
  -f, --force
  -v, --verbose
  -l LOG_LEVEL, --log_level=LOG_LEVEL
  --dry-run

Commmand line features

Gateway chaining

ssh foo.com/bar.com

Connect to bar.com using ssh and create a proxy on bar.com to foo.com. Then connect to foo.com using the created proxy on bar.com.

ssh foo.com/bar.com/baz.com

Connect to foo.com using bar.com/baz.com which itself uses baz.com.

Configuration features

regex for hostnames: gw.school-.*.domain.net
aliases: gate -> gate.domain.tld
gateways: transparent ssh connections chaining
includes: split configuration into multiple files
local command execution: finally a way to execute a command locally on connection
inheritance: inherits = gate.domain.tld
variable expansion: User = $USER (take $USER from environment)
smart proxycommand: connect using netcat, socat or custom handler

Config example

~/.ssh/config.advanced

# Simple example
[foo.com]
user = pacman
port = 2222

[bar]
hostname = 1.2.3.4
gateways = foo.com   # `ssh bar` will use `foo.com` as gateway

[^vm-[0-9]*\.joe\.com$]
gateways = bar       # `ssh vm-42.joe.com will use `bar` as gateway which
                     # itself will use `foo.com` as gateway

[default]
ProxyCommand = assh --port=%p connect %h

# Complete example
[foo]
user = pacman
port = 2222
hostname = foo.com

[bar]
hostname = 1.2.3.4
gateways = foo
# By running `ssh bar`, you will ssh to `bar` through a `ssh foo`

[^vm-[0-9]*\.joe\.com$]
IdentityFile = ~/.ssh/root-joe
gateways = direct joe.com joe.com/bar
# Will try to ssh without proxy, then fallback to joe.com proxy, then
# fallback to joe.com through bar
DynamicForward = 43217
LocalForward = 1723 localhost:1723
ForwardX11 = yes

[default]
Includes = ~/.ssh/config.advanced2 ~/.ssh/config.advanced3
Port = 22
User = root
IdentityFile = ~/.ssh/id_rsa
ProxyCommand = assh connect %h --port=%p
Gateways = direct
PubkeyAuthentication = yes
VisualHostKey = yes
ControlMaster = auto
ControlPath = ~/.ssh/controlmaster/%h-%p-%r.sock
EscapeChar = ~

Installation

Download the latest build

$ curl -L https://github.com/moul/advanced-ssh-config/releases/download/v1.0.1/assh-`uname -s`-`uname -m` > /usr/local/bin/assh
$ chmod +x /usr/local/bin/assh

Using Pypi

$ pip install advanced-ssh-config

Or by cloning

$ git clone https://github.com/moul/advanced-ssh-config
$ cd advanced-ssh-config
$ make install

First run

Automatically generate a new .ssh/config.advanced based on your current .ssh/config file:

$ assh init > ~/.ssh/config.advanced
$ assh build -f

Tests

$ make test

Docker

Build

$ docker build -t moul/advanced-ssh-config .

Run

$ docker run -rm -i -t moul/advanced-ssh-config
or
$ docker run -rm -i -t -v $(pwd)/:/advanced_ssh_config moul/advanced-ssh-config
or
$ docker run -rm -i -t -v moul/advanced-ssh-config python setup.py test

Contributors

Christo DeLange

yetone/advanced-ssh-config