SSH to Google Colaboratory with Serveo.net

I love Google Colab! It is perfect for running Deep Learning experiments on a budget. I like how nonrestrictive it is and how you can run whatever you want inside the container you are given.

Sometimes I like to connect via SSH and use a proper editor to edit my python scripts, and while Jupyter-like environment is great for visualizing etc. sometimes you just want a shell. Luckily you can SSH into your Colab runtime.

Now, full disclaimer, I do not know if Google allows this explicitly or they just didn’t consider it. If I am asked to remove this guide I will immediately do so.

To get SSH access you need a bridge of some sort. There are already some tutorials using ngrok but that requires you to make an account there. What I came up with is much simpler.

Here are the steps:

1. Open a new Colab notebook (you can name it ssh for future use)

2. Set your runtime to Python 3 and GPU (optional)

3. In a cell run the following code:

import random, string, getpass

password = ''.join(random.choice(string.ascii_letters + string.digits) for i in range(20))
alias = ''.join(random.choice(string.ascii_letters + string.digits) for i in range(8))
! echo root:$password | chpasswd

! apt-get install -qq -o=Dpkg::Use-Pty=0 openssh-server pwgen > /dev/null
! mkdir -p /var/run/sshd
! echo "PermitRootLogin yes" >> /etc/ssh/sshd_config && echo "PasswordAuthentication yes" >> /etc/ssh/sshd_config
! echo "LD_LIBRARY_PATH=/usr/lib64-nvidia" >> /root/.bashrc && echo "export LD_LIBRARY_PATH" >> /root/.bashrc
get_ipython().system_raw('/usr/sbin/sshd -D &')

print('sshpass -p {} ssh -o "StrictHostKeyChecking no" -J serveo.net root@{}'.format(password, alias))
! ssh -o "StrictHostKeyChecking no" -R $alias:22:localhost:22 serveo.net

That’s it! The output will be a command that you can run locally to connect. Package sshpass is required if you want to skip the password prompt, but unnecessary otherwise.

Example output:

sshpass -p Xw11kuSeS3F4hBSFkYs2 ssh -o "StrictHostKeyChecking no" -J serveo.net root@7oaEZMqW
Forwarding SSH traffic from alias "7oaezmqw"
Press g to start a GUI session and ctrl-c to quit.

I suggest installing tmux so you can resume your experiments if you get disconnected. You are root inside the container so you can install anything.

Let me know how it works!