How To Specify The Private SSH-key To Use When Executing

When executing an SSH command (such as connecting to a remote server or running commands via SSH), you can specify a particular private SSH key using the -i option, followed by the path to the private key file. This is helpful if you have multiple SSH keys and need to specify which one to use for a specific connection.

Syntax:

ssh -i /path/to/private-key user@host

• /path/to/private-key: The full path to the private SSH key file you want to use.
• user: The username you are logging in with.
• host: The hostname or IP address of the remote server.

Example:

Suppose you have a private SSH key stored at ~/.ssh/my_private_key and you want to use it to connect to a server with the username username at example.com.

ssh -i ~/.ssh/my_private_key [email protected]

Additional Considerations:

1. Permissions of the Private Key: Make sure the private key has appropriate permissions (e.g., 600), which means only the owner can read and write the file:

   chmod 600 ~/.ssh/my_private_key
   

2. Using SSH with Other Tools (e.g., Git): If you’re using Git or other tools that rely on SSH, you can specify the private key by setting the SSH_AUTH_SOCK environment variable or configuring the SSH client to use a specific key in the ~/.ssh/config file.
   

   Example for Git:

   If you use Git and want to specify an SSH key for a specific repository, you can set the GIT_SSH_COMMAND environment variable:

   GIT_SSH_COMMAND="ssh -i ~/.ssh/my_private_key" git clone [email protected]:username/repository.git
   

3. Using SSH Config File: You can configure SSH to automatically use a specific key for a given host by adding an entry to your SSH config file (~/.ssh/config):

   Host example.com
       User username
       IdentityFile ~/.ssh/my_private_key
   

   With this configuration, you can simply run:

   ssh example.com
   

   And it will automatically use the specified key for that host.