<filename>libcloud/common/base.py
# Licensed to the Apache Software Foundation (ASF) under one or more
# contributor license agreements.  See the NOTICE file distributed with
# this work for additional information regarding copyright ownership.
# The ASF licenses this file to You under the Apache License, Version 2.0
# (the "License"); you may not use this file except in compliance with
# the License.  You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

import httplib
import urllib
import time
import hashlib
import StringIO
import ssl
import os
import socket
import struct

from pipes import quote as pquote

import libcloud

from libcloud.httplib_ssl import LibcloudHTTPSConnection
from httplib import HTTPConnection as LibcloudHTTPConnection

class RawResponse(object):

    def __init__(self, response=None):
        self._status = None
        self._response = None
        self._headers = {}
        self._error = None
        self._reason = None

    @property
    def response(self):
        if not self._response:
            self._response = self.connection.connection.getresponse()
        return self._response

    @property
    def status(self):
        if not self._status:
            self._status = self.response.status
        return self._status

    @property
    def headers(self):
        if not self._headers:
            self._headers = dict(self.response.getheaders())
        return self._headers

    @property
    def reason(self):
        if not self._reason:
            self._reason = self.response.reason
        return self._reason

class Response(object):
    """
    A Base Response class to derive from.
    """
    NODE_STATE_MAP = {}

    object = None
    body = None
    status = httplib.OK
    headers = {}
    error = None
    connection = None

    def __init__(self, response):
        self.body = response.read()
        self.status = response.status
        self.headers = dict(response.getheaders())
        self.error = response.reason

        if not self.success():
            raise Exception(self.parse_error())

        self.object = self.parse_body()

    def parse_body(self):
        """
        Parse response body.

        Override in a provider's subclass.

        @return: Parsed body.
        """
        return self.body

    def parse_error(self):
        """
        Parse the error messages.

        Override in a provider's subclass.

        @return: Parsed error.
        """
        return self.body

    def success(self):
        """
        Determine if our request was successful.

        The meaning of this can be arbitrary; did we receive OK status? Did
        the node get created? Were we authenticated?

        @return: C{True} or C{False}
        """
        return self.status == httplib.OK or self.status == httplib.CREATED

#TODO: Move this to a better location/package
class LoggingConnection():
    """
    Debug class to log all HTTP(s) requests as they could be made
    with the C{curl} command.

    @cvar log: file-like object that logs entries are written to.
    """
    log = None

    def _log_response(self, r):
        rv = "# -------- begin %d:%d response ----------\n" % (id(self), id(r))
        ht = ""
        v = r.version
        if r.version == 10:
            v = "HTTP/1.0"
        if r.version == 11:
            v = "HTTP/1.1"
        ht += "%s %s %s\r\n" % (v, r.status, r.reason)
        body = r.read()
        for h in r.getheaders():
            ht += "%s: %s\r\n" % (h[0].title(), h[1])
        ht += "\r\n"
        # this is evil. laugh with me. ha arharhrhahahaha
        class fakesock:
            def __init__(self, s):
                self.s = s
            def makefile(self, mode, foo):
                return StringIO.StringIO(self.s)
        rr = r
        if r.chunked:
            ht += "%x\r\n" % (len(body))
            ht += body
            ht += "\r\n0\r\n"
        else:
            ht += body
        rr = httplib.HTTPResponse(fakesock(ht),
                                  method=r._method,
                                  debuglevel=r.debuglevel)
        rr.begin()
        rv += ht
        rv += ("\n# -------- end %d:%d response ----------\n"
               % (id(self), id(r)))
        return (rr, rv)

    def _log_curl(self, method, url, body, headers):
        cmd = ["curl", "-i"]

        cmd.extend(["-X", pquote(method)])

        for h in headers:
            cmd.extend(["-H", pquote("%s: %s" % (h, headers[h]))])

        # TODO: in python 2.6, body can be a file-like object.
        if body is not None and len(body) > 0:
            cmd.extend(["--data-binary", pquote(body)])

        cmd.extend([pquote("https://%s:%d%s" % (self.host, self.port, url))])
        return " ".join(cmd)

class LoggingHTTPSConnection(LoggingConnection, LibcloudHTTPSConnection):
    """
    Utility Class for logging HTTPS connections
    """

    def getresponse(self):
        r = LibcloudHTTPSConnection.getresponse(self)
        if self.log is not None:
            r, rv = self._log_response(r)
            self.log.write(rv + "\n")
            self.log.flush()
        return r

    def request(self, method, url, body=None, headers=None):
        headers.update({'X-LC-Request-ID': str(id(self))})
        if self.log is not None:
            pre = "# -------- begin %d request ----------\n"  % id(self)
            self.log.write(pre +
                           self._log_curl(method, url, body, headers) + "\n")
            self.log.flush()
        return LibcloudHTTPSConnection.request(self, method, url, body, headers)

class LoggingHTTPConnection(LoggingConnection, LibcloudHTTPConnection):
    """
    Utility Class for logging HTTP connections
    """

    def getresponse(self):
        r = LibcloudHTTPConnection.getresponse(self)
        if self.log is not None:
            r, rv = self._log_response(r)
            self.log.write(rv + "\n")
            self.log.flush()
        return r

    def request(self, method, url, body=None, headers=None):
        headers.update({'X-LC-Request-ID': str(id(self))})
        if self.log is not None:
            pre = "# -------- begin %d request ----------\n"  % id(self)
            self.log.write(pre +
                           self._log_curl(method, url, body, headers) + "\n")
            self.log.flush()
        return LibcloudHTTPConnection.request(self, method, url,
                                               body, headers)

class ConnectionKey(object):
    """
    A Base Connection class to derive from.
    """
    #conn_classes = (LoggingHTTPSConnection)
    conn_classes = (LibcloudHTTPConnection, LibcloudHTTPSConnection)

    responseCls = Response
    rawResponseCls = RawResponse
    connection = None
    host = '127.0.0.1'
    port = (80, 443)
    secure = 1
    driver = None
    action = None

    def __init__(self, key, secure=True, host=None, force_port=None):
        """
        Initialize `user_id` and `key`; set `secure` to an C{int} based on
        passed value.
        """
        self.key = key
        self.secure = secure and 1 or 0
        self.ua = []
        if host:
            self.host = host

        if force_port:
            self.port = (force_port, force_port)

    def connect(self, host=None, port=None):
        """
        Establish a connection with the API server.

        @type host: C{str}
        @param host: Optional host to override our default

        @type port: C{int}
        @param port: Optional port to override our default

        @returns: A connection
        """
        host = host or self.host
        port = port or self.port[self.secure]

        kwargs = {'host': host, 'port': port}

        connection = self.conn_classes[self.secure](**kwargs)
        # You can uncoment this line, if you setup a reverse proxy server
        # which proxies to your endpoint, and lets you easily capture
        # connections in cleartext when you setup the proxy to do SSL
        # for you
        #connection = self.conn_classes[False]("127.0.0.1", 8080)

        self.connection = connection

    def _user_agent(self):
        return 'libcloud/%s (%s)%s' % (
                  libcloud.__version__,
                  self.driver.name,
                  "".join([" (%s)" % x for x in self.ua]))

    def user_agent_append(self, token):
        """
        Append a token to a user agent string.

        Users of the library should call this to uniquely identify thier requests
        to a provider.

        @type token: C{str}
        @param token: Token to add to the user agent.
        """
        self.ua.append(token)

    def request(self,
                action,
                params=None,
                data='',
                headers=None,
                method='GET',
                raw=False):
        """
        Request a given `action`.

        Basically a wrapper around the connection
        object's `request` that does some helpful pre-processing.

        @type action: C{str}
        @param action: A path

        @type params: C{dict}
        @param params: Optional mapping of additional parameters to send. If
            None, leave as an empty C{dict}.

        @type data: C{unicode}
        @param data: A body of data to send with the request.

        @type headers: C{dict}
        @param headers: Extra headers to add to the request
            None, leave as an empty C{dict}.

        @type method: C{str}
        @param method: An HTTP method such as "GET" or "POST".

        @return: An instance of type I{responseCls}
        """
        if params is None:
            params = {}
        if headers is None:
            headers = {}

        self.action = action
        self.method = method
        # Extend default parameters
        params = self.add_default_params(params)
        # Extend default headers
        headers = self.add_default_headers(headers)
        # We always send a content length and user-agent header
        headers.update({'User-Agent': self._user_agent()})
        headers.update({'Host': self.host})
        # Encode data if necessary
        if data != '' and data != None:
            data = self.encode_data(data)

        if data is not None:
            headers.update({'Content-Length': str(len(data))})

        if params:
            url = '?'.join((action, urllib.urlencode(params)))
        else:
            url = action

        # Removed terrible hack...this a less-bad hack that doesn't execute a
        # request twice, but it's still a hack.
        self.connect()
        try:
            # @TODO: Should we just pass File object as body to request method
            # instead of dealing with splitting and sending the file ourselves?
            if raw:
                self.connection.putrequest(method, action)

                for key, value in headers.iteritems():
                    self.connection.putheader(key, value)

                self.connection.endheaders()
            else:
                self.connection.request(method=method, url=url, body=data,
                                        headers=headers)
        except ssl.SSLError, e:
            raise ssl.SSLError(str(e))

        if raw:
            response = self.rawResponseCls()
        else:
            response = self.responseCls(self.connection.getresponse())

        response.connection = self
        return response

    def add_default_params(self, params):
        """
        Adds default parameters (such as API key, version, etc.)
        to the passed `params`

        Should return a dictionary.
        """
        return params

    def add_default_headers(self, headers):
        """
        Adds default headers (such as Authorization, X-Foo-Bar)
        to the passed `headers`

        Should return a dictionary.
        """
        return headers

    def encode_data(self, data):
        """
        Encode body data.

        Override in a provider's subclass.
        """
        return data

class ConnectionUserAndKey(ConnectionKey):
    """
    Base connection which accepts a user_id and key
    """

    user_id = None

    def __init__(self, user_id, key, secure=True, host=None, port=None):
        super(ConnectionUserAndKey, self).__init__(key, secure, host, port)
        self.user_id = user_id
