Using SSH with GitHub and Dreamhost

In setting up my new Jekyll blog, I needed to do some research on setting up passwordless login to GitHub and Dreamhost on OS X. There are two main articles I used for doing this (see below), however I thought I would consolidate the steps to make setting this up easier. Keep in mind - these steps are strictly for Mac OS X. The articles linked at the end include instructions for other platforms.

GitHub SSH

You can get this setup and working relatively quickly with these steps:

1. Generate a new SSH key

$ ssh-keygen -t rsa -C "your_email@example.com"

When prompted to enter a filename, I prefer to add a username suffix to make separate keys easier to manage and remember. So instead of accepting the default name of id_rsa, I add a suffix to make it id_rsa_username.

2. Add your key to the ssh-agent

# Start the ssh-agent service...
$ eval "$(ssh-agent -s)"

# Add your newly generated key...
$ ssh-add ~/.ssh/id_rsa_username

If you forget this step, you won’t be able to successfully verify your configuration in Step 4 below.

3. Add your key to your GitHub account

# Copy the contents of the public SSH key to the clipboard...
$ pbcopy < ~/.ssh/id_rsa_username.pub

Once you have that copied, just log in to GitHub, click the Settings cog-wheel in the top and choose SSH Keys in the sidebar.

4. Verify it works

# Verify you can log in...
$ ssh -T git@github.com

If everything works, you should get a really confusing message saying you were successful but GitHub doesn’t allow shell access. Don’t worry - this is expected and you can ignore it. Enjoy passwordless git commits.

Read more on the GiHub article.

Bonus!

You’ll want to make sure you start cloning repositories using the SSH option. This typically means your URLs will look like this - git@github.com:USERNAME/REPOSITORY.git. If you have existing repositories that are linked to remotes over HTTPS, you can quickly and easily change those remote URLs with the following git commands:

# Change from HTTPS to SSH...
$ git remote set-url origin git@github.com:USERNAME/REPOSITORY.git

# Verify the change...
$ git remote -v
origin  git@github.com:USERNAME/REPOSITORY.git (fetch)
origin  git@github.com:USERNAME/REPOSITORY.git (push)

Read more on the GiHub article.

Dreamhost SSH

Just like the GitHub setup above, there are a few easy steps:

1. Generate a new SSH key

$ ssh-keygen -t rsa -C "your_email@example.com"

Again, when prompted to enter a filename, I prefer to add a username suffix to make separate keys easier to manage and remember.

2. Copy your key to the Dreamhost server

The Dreamhost wiki says that this command doesn’t work on OS X, but I had the opposite experience. I tried using the secondary approach and that didn’t seem to work, so I tried this and it did. I’m going to recommend you start with this one and if it doesn’t work, fall back on the second option in the article.

# Run this command and see if it works...
$ ssh-copy-id -i ~/.ssh/id_rsa_username.pub user@server.dreamhost.com

# If it doesn't work, try this...
$ cat ~/.ssh/id_rsa_username.pub | ssh user@server.dreamhost.com "cat >> ~/.ssh/authorized_keys"

3. Verify it works

# If you set this up correctly, you should see your Dreamhost shell...
$ ssh user@server.dreamhost.com

Read more on the Dreamhost article.