def ssh_into_instance()

in ebcli/operations/sshops.py [0:0]

• 60 lines of code
• 26 McCabe index (conditional complexity)

def ssh_into_instance(instance_id, keep_open=False, force_open=False, custom_ssh=None, command=None):
    instance = ec2.describe_instance(instance_id)
    try:
        keypair_name = instance['KeyName']
    except KeyError:
        raise NoKeypairError()
    try:
        ip = instance['PublicIpAddress']
    except KeyError:
        if 'PrivateIpAddress' in instance:
            ip = instance['PrivateIpAddress']
        else:
            raise NotFoundError(strings['ssh.noip'])
    security_groups = instance['SecurityGroups']

    user = 'ec2-user'

    ssh_group = None
    has_restriction = False
    rule_existed_before = False
    group_id = None
    for group in security_groups:
        group_id = group['GroupId']
        group = ec2.describe_security_group(group_id)
        for permission in group.get('IpPermissions', []):
            if permission.get('ToPort', None) == 22:
                ssh_group = group_id
                for rng in permission.get('IpRanges', []):
                    ip_restriction = rng.get('CidrIp', None)
                    if ip_restriction is not None:
                        if ip_restriction != '0.0.0.0/0':
                            has_restriction = True
                        elif ip_restriction == '0.0.0.0/0':
                            rule_existed_before = True

    if has_restriction and not force_open:
        io.log_warning(strings['ssh.notopening'])
    elif group_id and not rule_existed_before:
        io.echo(strings['ssh.openingport'])
        ec2.authorize_ssh(ssh_group or group_id)
        io.echo(strings['ssh.portopen'])

    try:
        if custom_ssh:
            custom_ssh = custom_ssh.split()
        else:
            ident_file = _get_ssh_file(keypair_name)
            custom_ssh = ['ssh', '-i', ident_file, '-o', 'IdentitiesOnly yes']

        custom_ssh.extend([user + '@' + ip])

        if command:
            custom_ssh.extend(command.split())

        io.echo('INFO: Running ' + ' '.join(custom_ssh))
        returncode = subprocess.call(custom_ssh)
        if returncode != 0:
            LOG.debug(custom_ssh[0] + ' returned exitcode: ' + str(returncode))
            raise CommandError('An error occurred while running: ' + custom_ssh[0] + '.')
    except OSError:
        CommandError(strings['ssh.notpresent'])
    finally:
        if keep_open:
            pass
        elif (not has_restriction or force_open) and group_id and not rule_existed_before:
            ec2.revoke_ssh(ssh_group or group_id)
            io.echo(strings['ssh.closeport'])