title: Git: access a remote repository over ssh using a key file but without using ~/.ssh/config
body: <p>Is it possible to access (<code>fetch</code>/<code>push</code>) a remote repository using ssh and an identity file (with the private key) without adding an entry in the file <code>~/.ssh/config</code> such as:</p>
  
  <pre><code>Host tingle
    HostName 111.222.333.444
    User git
    IdentityFile c/tmp/my_id_rsa
  </code></pre>
  
  <p>Everything works fine when configuring the <code>~/.ssh/config</code> file. However we have a script which clones from a remote repo, checks out, starts testing, commits results and pushes them. The script need to run on any machine without touching the ssh config file.</p>