git-references

< Git References

USE MULTIPLE GIT IDENTITIES ON ONE MACHINE

manually switch ssh key

Go to your .ssh/ directory.

• id_ed25519
• id_ed25519.pub - public key

These files are the global ssh key your git installation will use. You can rename the files and generate a new ssh key for another account. I tack the username for the account onto the filenames:

• id_ed25519-crybx
• id_ed25519-crybx.pub

Whichever account you want to use to auth through ssh with needs to be the files named id_ed25519 and id_ed25519.pub. Any with username appended are not currently being used.

You can rename the files every time you want to switch, or…

use multiple ssh keys without file renaming

You can configure individual repositories to use a specific ssh key (e.g. one with a username appended).

This approach ensures that the designated key is used whenever you interact with that repo, without affecting other repos.

• Locate the repo’s config file: Navigate to the root directory of your local git repo in the terminal. The config file is located in the .git subdirectory and is named config.
• Edit the config file: Use any text editor to open it.
• Add or modify the core.sshCommand setting: Under the [core] section, add or modify the sshCommand setting to specify the ssh key to use for the repository. The format for this setting is:

[core]
    sshCommand = ssh -i /path/to/your/private_key -F /dev/null`

for my user

[core]
    sshCommand = ssh -i ~/.ssh/id_ed25519-crybx -F /dev/null

Replace /path/to/your/private_key with the actual path to your private key file. The -F /dev/null option prevents SSH from using the global ssh configuration file, ensuring that only the specified key is used. For example, if your private key is located at ~/.ssh/my_repo_key, the setting would look like this: [core] sshCommand = ssh -i ~/.ssh/my_repo_key -F /dev/null

• Save the changes: Save the modified config file.
• Verify the configuration: To confirm that the config is set correctly, you can use:

git config core.sshCommand

This will output the configured sshCommand value, allowing you to verify that it is pointing to the correct ssh key.

compare to global:

git config --global core.sshCommand

With this config in place, git will automatically use the specified ssh key when cloning, fetching, and pushing with the repo.

remember to update user and email for commits

You went to all that trouble to use a separate ssh key, don’t forget your username and email. Inside the repo that should use the different username and email address:

git config user.name "2ndusername"     
git config user.email "2nduseremailaddress"

Compare global vs local credentials:

git config user.name     
git config user.email
git config --global user.name     
git config --global user.email