Sometimes while working with the various ssh keys you have you might need to regenerate them. Specifically I ran into this need while working with some Google Cloud Platform (GCP) instances with Terraform and GCP’s gcloud CLI tool. Generally, when you start working with the gcloud CLI it will, upon need if it doesn’t exist, create a key for you. When it does so it sticks the key it generates in the ~/.ssh/ directory and names the key google_compute_engine. To create a new ssh key pair here, navigate to the ~/.ssh/ directory and issue the following command.

sudo ssh-keygen -t rsa -f ~/.ssh/google_compute_engine -C

Once that is command is executed, a few moments later and a few prompts later you’ll have a new key.

13:16 $ sudo ssh-keygen -t rsa -f ~/.ssh/google_compute_engine -C adron_hall@homedepot.comPassword:
Generating public/private rsa key pair.
/Users/axh6454/.ssh/google_compute_engine already exists.
Overwrite (y/n)? y
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/axh6454/.ssh/google_compute_engine.
Your public key has been saved in /Users/axh6454/.ssh/
The key fingerprint is:
The key's randomart image is:
+---[RSA 2048]----+
|           ooBB= |
|          o.=.E.+|
|          .= *.*o|
|          .o+o= o|
|        S . *=o= |
|         o * +=.o|
|          o o +oo|
|           . = .o|
|           .+ .  |
✔ ~/.ssh
13:16 $

That’s it. Sort of. For GCP be sure to check out the docs on managing ssh keys. There are docs on gcloud compute config-ssh and Adding and Removing SSH keys.