Set up SSH access for an Ubuntu server

You've signed up for a VPS, and now you have received root access into the server. Before you do anything else, it's always a good idea to properly set up ssh access, because it's more secure and more convenient.

Note: This guide assumes you are running OSX or Linux locally. The instructions for Windows will be different.

Here's how:

Step 1

If you haven't already, generate a public-private keypair on your local client.

ssh-keygen -t rsa

Feel free to leave all the options blank. You should get an output that looks like this:

Your identification has been saved in /home/vagrant/.ssh/id_rsa.
Your public key has been saved in /home/vagrant/.ssh/id_rsa.pub.
The key fingerprint is:
15:0b:f4:36:08:de:df:cb:7d:72:04:0e:7c:3d:97:51 vagrant@vagrant-ubuntu-trusty-64
The key's randomart image is:
+--[ RSA 2048]----+
|      ..o .    .E|
|     . o + +   .o|
|      . o * o ooo|
|         + o + .o|
|        S . . . .|
|           . o . |
|            o o o|
|               + |
|                 |
+-----------------+

Take note of the path to the public key, which in my case is /home/vagrant/.ssh/id_rsa.pub.

Step 2

Log into the VPS using ssh, replacing "123.456.789.12" with your VPS IP address:

ssh [email protected]

Step 3

Once you're in, create a new user account on the target server.

sudo adduser <username>

Follow the onscreen instructions to set up the account.

Step 4

Grant that user sudo access by adding it to the sudo group:

sudo adduser <username> sudo

Step 5

While you're here, it's always a good idea to disable root ssh access.

cp /etc/sshd_config /etc/backup_sshd_config
sudo nano /etc/sshd_config

Look for the line that begins with PermitRootLogin, and make sure it says

PermitRootLogin without-password

Restart the sshd service:

service ssh restart

Step 6

Return to your local terminal by typing exit. Now you need to copy your public key into the server, like so:

ssh-copy-id <username>@123.456.78.10

Enter that user's password when requested.

Congratulations, you're done! Check that you can access your server via SSH by entering

ssh <username>@123.456.78.10