indusism
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indusism

Add SSH key after creating a droplet

May 14, 2014 61k views
Hi There, I did not add the SSH key before creating the droplet. Now my server is all set and is about to go live. I cannot setup another one but really need to add an SSH key. Is there any way I could do that. Also I cannot se any droplet resize option available, any ideas why is that? I'm currently running LAMP on Ubuntu 12. 512 MB droplet. Thanks.
6 comments
9 Answers
To add a SSH key after the creation of the droplet, you need to add the contents of the public key to the file ~/.ssh/authorized_keys You can do that by running this on your local computer:


cat ~/.ssh/id_rsa.pub | ssh root@your.ip.address "cat >> ~/.ssh/authorized_keys"


You need to power down the droplet before you can resize it.
  • how do you do the adding shh? i mean please explain this command,, and where do i do this?

  • I get the following when entering the root password:

    WARNING: Your password has expired.
    Password change required but no TTY available.
    

    Nothing happens afterwards.

  • This worked perfectly for me. Thanks a million!

I would advise this guide here for the first part of your question:

https://www.digitalocean.com/community/articles/how-to-set-up-ssh-keys--2
by Etel Sverdlov
SSH keys provide a more secure way of logging into a virtual private server with SSH than using a password alone. With SSH keys, users can log into a server without a password. This tutorial explains how to generate, use, and upload an SSH Key Pair.
You definitely can add an SSH key after creating a droplet. See How To Set Up SSH Keys.
Also I cannot se any droplet resize option available, any ideas why is that?
It could be that the physical server that your droplet is on does not have enough available space to resize your droplet -- can you post a screenshot of the resize page?
by Etel Sverdlov
SSH keys provide a more secure way of logging into a virtual private server with SSH than using a password alone. With SSH keys, users can log into a server without a password. This tutorial explains how to generate, use, and upload an SSH Key Pair.
To resize the droplet, you're going to need to take a snapshot and then spin it up as a new droplet. A great guide can be found here.

https://www.digitalocean.com/community/articles/how-to-resize-droplets-using-snapshots
by Etel Sverdlov
This tutorial covers how to manually migrate droplets between hypervisors by taking a snapshot of the droplet and then spinning it up in a large or smaller size.

I didn't see this in the answers below.
But if you already have a public key that you want to reuse, you can just add it to ~/.ssh/authorized_keys file.

For anyone finding this via Google that found this answer: logging into your droplets via SSH on a Windows machine where you might be using a specialized client to generate your keys, the command asb uses in this comment thread doesn't work, and there really aren't any answers to tell you why.

Here's an explanation. For a quick command-line copy and paste answer, scroll to the bottom of this comment. Breaking down the command:

cat ~/.ssh/id_rsa.pub

On a *NIX machine, this would output your local public SSH key.

|

The pipe character is standard Shell-speak for "piping" data into the stdin (input console) of a program or file handle. An easy way to remember it is the output of the command on the left will be received as input for the command on the right.

ssh root@your.ip.address "cat >> ~/.ssh/authorized_keys"

This is standard use of the SSH command, except the part in quotes actually encloses a command to send to the server you're SSHing into.

What this adds up to mean is "output my local public key into the authorized_keys file on the server I'm SSHing into". Which, on Windows, unless you use a platform like Cygwin for all of your SSH, means it wouldn't work, because Windows isn't a *NIX-style platform.

Solution for Windows users using native SSH clients: Paste the following into a root shell on your droplet:

echo "YOUR_SSH_PUBKEY_GOES_HERE" >> ~/.ssh/authorized_keys

Your SSH key should now be authorized on the droplet.

by Etel Sverdlov
SSH keys provide a more secure way of logging into a virtual private server with SSH than using a password alone. With SSH keys, users can log into a server without a password. This tutorial explains how to generate, use, and upload an SSH Key Pair.

Here is the working guide on how to add a SSH key to existing droplet (for Windows users)
http://geektnt.com/how-to-add-ssh-key-to-existing-digitalocean-droplet.html

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