def add_ssh_key(identity_file=None):
"""Install ssh key into user's iot-lab account"""
if identity_file is None:
identity_file = IDENTITY_FILE
api = Api(*get_user_credentials())
keys_json = api.get_ssh_keys()
pub_key = identity_file + '.pub'
with open(pub_key) as key_fh:
key = key_fh.read().strip()
keys = keys_json['sshkeys']
if key in keys:
msg = f'Key is already configured:\n"{key}"'
raise ValueError(msg)
keys.append(key)
api.set_ssh_keys(keys_json)
