Copyright 2012 by Derek A. Thomas
Working on large servers containing multiple machines hidden behind a central server is a pain. I find myself taking time just to jump between the different computers with an anoying middle man getting in the way. That's where tunneling comes in, which is frequently use to forward ports so that we can more easily connect from one machine to another.
# the setup is kinda like this:
+----------------+
Time consuming multiple jumps | |
+-------o other computer |
+-----------+ +-------------+ | | |
| | | central | | +----------------+
| my local | |-------------| |
| computer +----------> | gate +---------+
| | | keeper | |
| | | | | +---------------+
+------v----+ +-------------+ | | remote server |
| +-------o ----------- |
| using tssh, the connection seems direct | Gotta get work|
+------------->----------->------------>----------o done |
+---------------+
With tssh, I hope that the whole act of tunneling can be greatly simplified with the least amount of load or cost to your computers or servers.
Installation is quite simple. Here's an example script that installs tssh.
#!/bin/sh
tmp=$(mktemp -d)
git clone [email protected]:scicalculator/tssh.git $tmp
pushd . > /dev/null
cd $tmp/bin
# now link the files to our bin directory
for file in $(ls) ; do
ln -s $PWD/$file $HOME/bin
done
popd > /dev/null
rm -r $tmp
# all done
You can copy it to any file usch as tssh-install.sh and run it like:
$ chmod +x tssh-install.sh
$ ./tssh-install.sh
tssh uses a log file ~/.tsshrc to hold a list of know servers and central
servers (currently limited to 1) that several machines are behind. The file can
be automatically generated like follows:
# let's set up our server list
$ tssh-setup
tssh-setup: setup for server list
- creating new file: ~/.tsshrc
- append a star at the end of servernames
for the central, port-forwarding server
- Port is optional, but is used for port forwarding
1. Name: central*
address: example.com
user: my_username
port:
msg(not a password) :
2. Name: remote_server
address: 198.168.1.100
user: some_username
port: 7070
msg(not a password):
> tmux attach
3. Name: ^C
tssh-setup: 2 servers added
# now let's print out the server list just to make sure
$ tssh-setup -p
---- .tsshrc ----
name | address | user | port | message
********************************************************************************
central* | example.com | my_username | |
remote_server | 198.168.1.100 | some_username | 7070 | tmux attach
---- .tsshrc ----
# Remeber, it is important to give attach a '*' to the computer acting as your
# central gate. There are currently no checks in place to make sure you do this
# since you can add them in any order.
We're all setup now to bounce to remote_server directly! Time to get on over there.
Now to get to the meat of it, the actual tssh program. With this
program you can do some interesting things.
-
First, we can connect directly to the server, which automatically runs our default message. This setups up a tunnel through the "central" computer to "remote_server" on the remote LAN. Also, when you disconnect, it will automatically free up your port (e.g. 7070 or whatever you set it) when you are done.
$ tssh remote tssh: remote tunnel -> remote_server
-
A new message can be sent.
$ tssh remote "echo hello ; sleep 5 ; echo byebye" tssh: remote_server message: echo hello ; sleep 5 ; echo byebye tunnel -> remote_server hello byebye $
-
Also, we can setup a proxy server to our central node. This is helpful when your remote server has access to certain websites that you want to to gain access to from outside of the LAN.
$ tssh -P 5050 tssh: Proxy to central* > port 5050 my_username@central: ~ >
For those times you need to interact directly with your remote computer's file
system, I've got you covered. To use this, you must install sshfs, which is
available on most package distributions. By default, sshfs connects are mounted
in ~/sshfs/${server-name}, but the directory can be customized with the
environent variable SSHFS_DIR, which will be a place to mount your remote
file systems.
# ok, now let's get going
$ tssfs remote
tsshfs: successfully mounted /Users/user_name/sshfs/remote_server
# now you can go there and see what's available
$ cd ~/sshfs/remote_server
$ ls
another_dir dev some_file
$ tree
├── another_dir
├── dev
│ └── something.git
│ └── README.md
└── some_file
# now let's unmount it (you can do this from anywhere outside of the directory)
$ cd
$ tumount remote
tumount: successfully unmounted /Users/user_name/sshfs/remote_server
Copyright (c) 2012 Derek Ashley Thomas
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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