Username - The name of the user account that the SSH key will be associated with.
If an SSH key username is specified, it must match the username specified for the image used to create the virtual machine. Alternatively, the SSH key username can be left blank to allow access to all images.
Once these fields have been filled out appropriately, click the Save button. A job is submitted to create the SSH key. To use the SSH key to access a virtual machine, the SSH key must be extracted from the virtual machine's metadata. The easiest way to ensure that this happens is to add the SSH key to the server's metadata before the virtual machine is first booted. The firstboot script should then extract the SSH key from the virtual machine's metadata. Global SSH keys are automatically added to the metadata of all new virtual machines. Non-global SSH keys can be added to the metadata of a virtual machine when managing the virtual machine.