SSH configuration for Git repository

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git
ssh
How to configure SSH access to Git repository

TL;DR

Generate SSH key and add to SSH agent in the local machine:

ssh-keygen -t ed25519 -C "sample.mail@gmail.com" # Specify appropiate key name when prompted
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/[key_name]

At this point, copy and paste the public key to your repo’s SSH key manager:

cat ~/.ssh/[key_name].pub # Copy the output of this command and paste to key manager

Configure a new SSH entry in the SSH config file ~/ssh/config. Write the following:

Host [repo_alias_hostname] # E.g. github.com, or some alias, e.g. work.github.com, if you want to manage multiple accounts
    HostName [repo_hostname] # Repo host name
    User [username] # User name in the repository
    PubKeyAuthentication yes
    IdentityFile ~/.ssh/[key_name] # Key file generated above

Breakdown

  1. There are several algorithms to generate the SSH keys. Check the references in your Git repository’s key manager. The key generation steps can be found in any popular Git repository (Github, Gitlab…).
  2. The SSH config file is not necessary but it is very useful to handle multiple Git accounts.
  3. In the SSH config file, HostName can be an IP address if known, which will skip domain resolution, or a host name, which will trigger domain resolution. This may be resolved locally via /etc/hosts or require DNS queries.

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