~launchpad-pqm/launchpad/devel

# Copyright 2009 Canonical Ltd.  This software is licensed under the

# GNU Affero General Public License version 3 (see the file LICENSE).

"""Support for reading Amazon Web Service credentials from '~/.ec2/aws_id'."""

__metaclass__ = type

__all__ = [

    'CredentialsError',

    'EC2Credentials',

    ]

import os

import boto

from bzrlib.errors import BzrCommandError

from devscripts.ec2test.account import EC2Account

class CredentialsError(BzrCommandError):

    """Raised when AWS credentials could not be loaded."""

    def __init__(self, filename, extra=None):

        message = (

            "Please put your aws access key identifier and secret access "

            "key identifier in %s. (On two lines)." % (filename,))

        if extra:

            message += extra

        Exception.__init__(self, message)

class EC2Credentials:

    """Credentials for logging in to EC2."""

    DEFAULT_CREDENTIALS_FILE = '~/.ec2/aws_id'

    def __init__(self, identifier, secret):

        self.identifier = identifier

        self.secret = secret

    @classmethod

    def load_from_file(cls, filename=None):

        """Load the EC2 credentials from 'filename'."""

        if filename is None:

            filename = os.path.expanduser(cls.DEFAULT_CREDENTIALS_FILE)

        try:

            aws_file = open(filename, 'r')

        except (IOError, OSError), e:

            raise CredentialsError(filename, str(e))

        try:

            identifier = aws_file.readline().strip()

            secret = aws_file.readline().strip()

        finally:

            aws_file.close()

        return cls(identifier, secret)

    def connect(self, name):

        """Connect to EC2 with these credentials.

        :param name: ???

        :return: An `EC2Account` connected to EC2 with these credentials.

        """

        conn = boto.connect_ec2(self.identifier, self.secret)

        return EC2Account(name, conn)

    def connect_s3(self):

        """Connect to S3 with these credentials.

        :return: A `boto.s3.connection.S3Connection` with these credentials.

        """

        return boto.connect_s3(self.identifier, self.secret)