Add some documentation for cluster management
[kamaki] / kamaki / clients / __init__.py
index 990e65e..266b3fc 100644 (file)
@@ -1,4 +1,4 @@
-# Copyright 2011-2012 GRNET S.A. All rights reserved.
+# Copyright 2011-2013 GRNET S.A. All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or
 # without modification, are permitted provided that the following
 # interpreted as representing official policies, either expressed
 # or implied, of GRNET S.A.
 
-import json
-import logging
-from .connection import HTTPConnectionError
-#from .connection.request import HTTPRequest
-from .connection.kamakicon import KamakiHTTPConnection
+from urllib2 import quote, unquote
+from urlparse import urlparse
+from threading import Thread
+from json import dumps, loads
+from time import time
+from httplib import ResponseNotReady, HTTPException
+from time import sleep
+from random import random
+from logging import getLogger
 
-sendlog = logging.getLogger('clients.send')
-recvlog = logging.getLogger('clients.recv')
+from objpool.http import PooledHTTPConnection
+
+
+TIMEOUT = 60.0   # seconds
+HTTP_METHODS = ['GET', 'POST', 'PUT', 'HEAD', 'DELETE', 'COPY', 'MOVE']
+
+log = getLogger(__name__)
+sendlog = getLogger('%s.send' % __name__)
+recvlog = getLogger('%s.recv' % __name__)
+
+
+def _encode(v):
+    if v and isinstance(v, unicode):
+        return quote(v.encode('utf-8'))
+    return v
 
 
 class ClientError(Exception):
-    def __init__(self, message, status=0, details=''):
-        super(ClientError, self).__init__(message, status, details)
-        self.message = message
-        self.status = status
-        self.details = details
+    def __init__(self, message, status=0, details=None):
+        log.debug('ClientError: msg[%s], sts[%s], dtl[%s]' % (
+            message,
+            status,
+            details))
+        try:
+            message += '' if message and message[-1] == '\n' else '\n'
+            serv_stat, sep, new_msg = message.partition('{')
+            new_msg = sep + new_msg[:-1 if new_msg.endswith('\n') else 0]
+            json_msg = loads(new_msg)
+            key = json_msg.keys()[0]
+            serv_stat = serv_stat.strip()
+
+            json_msg = json_msg[key]
+            message = '%s %s (%s)\n' % (
+                serv_stat,
+                key,
+                json_msg['message']) if (
+                    'message' in json_msg) else '%s %s' % (serv_stat, key)
+            status = json_msg.get('code', status)
+            if 'details' in json_msg:
+                if not details:
+                    details = []
+                if not isinstance(details, list):
+                    details = [details]
+                if json_msg['details']:
+                    details.append(json_msg['details'])
+        except Exception:
+            pass
+        finally:
+            while message.endswith('\n\n'):
+                message = message[:-1]
+            super(ClientError, self).__init__(message)
+            self.status = status if isinstance(status, int) else 0
+            self.details = details if details else []
+
+
+class Logged(object):
+
+    LOG_TOKEN = False
+    LOG_DATA = False
+    LOG_PID = False
+    _token = None
+
+
+class RequestManager(Logged):
+    """Handle http request information"""
+
+    def _connection_info(self, url, path, params={}):
+        """ Set self.url to scheme://netloc/?params
+        :param url: (str or unicode) The service url
+
+        :param path: (str or unicode) The service path (url/path)
+
+        :param params: (dict) Parameters to add to final url
+
+        :returns: (scheme, netloc)
+        """
+        url = _encode(str(url)) if url else 'http://127.0.0.1/'
+        url += '' if url.endswith('/') else '/'
+        if path:
+            url += _encode(path[1:] if path.startswith('/') else path)
+        delim = '?'
+        for key, val in params.items():
+            val = '' if val in (None, False) else _encode(u'%s' % val)
+            url += '%s%s%s' % (delim, key, ('=%s' % val) if val else '')
+            delim = '&'
+        parsed = urlparse(url)
+        self.url = url
+        self.path = parsed.path or '/'
+        if parsed.query:
+            self.path += '?%s' % parsed.query
+        return (parsed.scheme, parsed.netloc)
+
+    def __init__(
+            self, method, url, path,
+            data=None, headers={}, params={}):
+        method = method.upper()
+        assert method in HTTP_METHODS, 'Invalid http method %s' % method
+        if headers:
+            assert isinstance(headers, dict)
+        self.headers = dict(headers)
+        self.method, self.data = method, data
+        self.scheme, self.netloc = self._connection_info(url, path, params)
+
+    def dump_log(self):
+        plog = '\t[%s]' if self.LOG_PID else ''
+        sendlog.info('- -  -   -     -        -             -')
+        sendlog.info('%s %s://%s%s%s' % (
+            self.method, self.scheme, self.netloc, self.path, plog))
+        for key, val in self.headers.items():
+            if key.lower() in ('x-auth-token', ) and not self.LOG_TOKEN:
+                self._token, val = val, '...'
+            sendlog.info('  %s: %s%s' % (key, val, plog))
+        if self.data:
+            sendlog.info('data size:%s%s' % (len(self.data), plog))
+            if self.LOG_DATA:
+                sendlog.info(self.data.replace(self._token, '...') if (
+                    self._token) else self.data)
+        else:
+            sendlog.info('data size:0%s' % plog)
+
+    def perform(self, conn):
+        """
+        :param conn: (httplib connection object)
+
+        :returns: (HTTPResponse)
+        """
+        self.dump_log()
+        conn.request(
+            method=str(self.method.upper()),
+            url=str(self.path),
+            headers=self.headers,
+            body=self.data)
+        sendlog.info('')
+        keep_trying = TIMEOUT
+        while keep_trying > 0:
+            try:
+                return conn.getresponse()
+            except ResponseNotReady:
+                wait = 0.03 * random()
+                sleep(wait)
+                keep_trying -= wait
+        plog = '\t[%s]' if self.LOG_PID else ''
+        logmsg = 'Kamaki Timeout %s %s%s' % (self.method, self.path, plog)
+        recvlog.debug(logmsg)
+        raise ClientError('HTTPResponse takes too long - kamaki timeout')
+
+
+class ResponseManager(Logged):
+    """Manage the http request and handle the response data, headers, etc."""
+
+    def __init__(self, request, poolsize=None, connection_retry_limit=0):
+        """
+        :param request: (RequestManager)
+
+        :param poolsize: (int) the size of the connection pool
+
+        :param connection_retry_limit: (int)
+        """
+        self.CONNECTION_TRY_LIMIT = 1 + connection_retry_limit
+        self.request = request
+        self._request_performed = False
+        self.poolsize = poolsize
+
+    def _get_response(self):
+        if self._request_performed:
+            return
+
+        pool_kw = dict(size=self.poolsize) if self.poolsize else dict()
+        for retries in range(1, self.CONNECTION_TRY_LIMIT + 1):
+            try:
+                with PooledHTTPConnection(
+                        self.request.netloc, self.request.scheme,
+                        **pool_kw) as connection:
+                    self.request.LOG_TOKEN = self.LOG_TOKEN
+                    self.request.LOG_DATA = self.LOG_DATA
+                    self.request.LOG_PID = self.LOG_PID
+                    r = self.request.perform(connection)
+                    plog = ''
+                    if self.LOG_PID:
+                        recvlog.info('\n%s <-- %s <-- [req: %s]\n' % (
+                            self, r, self.request))
+                        plog = '\t[%s]' % self
+                    self._request_performed = True
+                    self._status_code, self._status = r.status, unquote(
+                        r.reason)
+                    recvlog.info(
+                        '%d %s%s' % (
+                            self.status_code, self.status, plog))
+                    self._headers = dict()
+                    for k, v in r.getheaders():
+                        if k.lower in ('x-auth-token', ) and (
+                                not self.LOG_TOKEN):
+                            self._token, v = v, '...'
+                        v = unquote(v)
+                        self._headers[k] = v
+                        recvlog.info('  %s: %s%s' % (k, v, plog))
+                    self._content = r.read()
+                    recvlog.info('data size: %s%s' % (
+                        len(self._content) if self._content else 0, plog))
+                    if self.LOG_DATA and self._content:
+                        data = '%s%s' % (self._content, plog)
+                        if self._token:
+                            data = data.replace(self._token, '...')
+                        sendlog.info(data)
+                    sendlog.info('-             -        -     -   -  - -')
+                break
+            except Exception as err:
+                if isinstance(err, HTTPException):
+                    if retries >= self.CONNECTION_TRY_LIMIT:
+                        raise ClientError(
+                            'Connection to %s failed %s times (%s: %s )' % (
+                                self.request.url, retries, type(err), err))
+                else:
+                    from traceback import format_stack
+                    recvlog.debug(
+                        '\n'.join(['%s' % type(err)] + format_stack()))
+                    raise ClientError(
+                        'Failed while http-connecting to %s (%s)' % (
+                            self.request.url, err))
 
-class Client(object):
+    @property
+    def status_code(self):
+        self._get_response()
+        return self._status_code
 
-    def __init__(self, base_url, token, http_client=KamakiHTTPConnection()):
-    #def __init__(self, base_url, token, http_client=HTTPRequest()):
+    @property
+    def status(self):
+        self._get_response()
+        return self._status
+
+    @property
+    def headers(self):
+        self._get_response()
+        return self._headers
+
+    @property
+    def content(self):
+        self._get_response()
+        return self._content
+
+    @property
+    def text(self):
+        """
+        :returns: (str) content
+        """
+        self._get_response()
+        return '%s' % self._content
+
+    @property
+    def json(self):
+        """
+        :returns: (dict) squeezed from json-formated content
+        """
+        self._get_response()
+        try:
+            return loads(self._content)
+        except ValueError as err:
+            raise ClientError('Response not formated in JSON - %s' % err)
+
+
+class SilentEvent(Thread):
+    """Thread-run method(*args, **kwargs)"""
+    def __init__(self, method, *args, **kwargs):
+        super(self.__class__, self).__init__()
+        self.method = method
+        self.args = args
+        self.kwargs = kwargs
+
+    @property
+    def exception(self):
+        return getattr(self, '_exception', False)
+
+    @property
+    def value(self):
+        return getattr(self, '_value', None)
+
+    def run(self):
+        try:
+            self._value = self.method(*(self.args), **(self.kwargs))
+        except Exception as e:
+            recvlog.debug('Thread %s got exception %s\n<%s %s' % (
+                self,
+                type(e),
+                e.status if isinstance(e, ClientError) else '',
+                e))
+            self._exception = e
+
+
+class Client(Logged):
+
+    MAX_THREADS = 7
+    DATE_FORMATS = ['%a %b %d %H:%M:%S %Y', ]
+    CONNECTION_RETRY_LIMIT = 0
+
+    def __init__(self, base_url, token):
+        assert base_url, 'No base_url for client %s' % self
         self.base_url = base_url
         self.token = token
-        self.headers = {}
-        self.DATE_FORMATS = ["%a %b %d %H:%M:%S %Y",
-            "%A, %d-%b-%y %H:%M:%S GMT",
-            "%a, %d %b %Y %H:%M:%S GMT"]
-        self.http_client = http_client
+        self.headers, self.params = dict(), dict()
+
+    def _init_thread_limit(self, limit=1):
+        assert isinstance(limit, int) and limit > 0, 'Thread limit not a +int'
+        self._thread_limit = limit
+        self._elapsed_old = 0.0
+        self._elapsed_new = 0.0
+
+    def _watch_thread_limit(self, threadlist):
+        self._thread_limit = getattr(self, '_thread_limit', 1)
+        self._elapsed_new = getattr(self, '_elapsed_new', 0.0)
+        self._elapsed_old = getattr(self, '_elapsed_old', 0.0)
+        recvlog.debug('# running threads: %s' % len(threadlist))
+        if self._elapsed_old and self._elapsed_old >= self._elapsed_new and (
+                self._thread_limit < self.MAX_THREADS):
+            self._thread_limit += 1
+        elif self._elapsed_old <= self._elapsed_new and self._thread_limit > 1:
+            self._thread_limit -= 1
+
+        self._elapsed_old = self._elapsed_new
+        if len(threadlist) >= self._thread_limit:
+            self._elapsed_new = 0.0
+            for thread in threadlist:
+                begin_time = time()
+                thread.join()
+                self._elapsed_new += time() - begin_time
+            self._elapsed_new = self._elapsed_new / len(threadlist)
+            return []
+        return threadlist
+
+    def async_run(self, method, kwarg_list):
+        """Fire threads of operations
+
+        :param method: the method to run in each thread
+
+        :param kwarg_list: (list of dicts) the arguments to pass in each method
+            call
+
+        :returns: (list) the results of each method call w.r. to the order of
+            kwarg_list
+        """
+        flying, results = {}, {}
+        self._init_thread_limit()
+        for index, kwargs in enumerate(kwarg_list):
+            self._watch_thread_limit(flying.values())
+            flying[index] = SilentEvent(method=method, **kwargs)
+            flying[index].start()
+            unfinished = {}
+            for key, thread in flying.items():
+                if thread.isAlive():
+                    unfinished[key] = thread
+                elif thread.exception:
+                    raise thread.exception
+                else:
+                    results[key] = thread.value
+            flying = unfinished
+        sendlog.info('- - - wait for threads to finish')
+        for key, thread in flying.items():
+            if thread.isAlive():
+                thread.join()
+            if thread.exception:
+                raise thread.exception
+            results[key] = thread.value
+        return results.values()
 
     def _raise_for_status(self, r):
-        message = "%d %s" % (r.status_code, r.status)
+        log.debug('raise err from [%s] of type[%s]' % (r, type(r)))
+        status_msg = getattr(r, 'status', None) or ''
         try:
-            details = r.text
+            message = '%s %s\n' % (status_msg, r.text)
         except:
-            details = ''
-        raise ClientError(message, r.status_code, details)
+            message = '%s %s\n' % (status_msg, r)
+        status = getattr(r, 'status_code', getattr(r, 'status', 0))
+        raise ClientError(message, status=status)
 
     def set_header(self, name, value, iff=True):
-        """Set a header 'name':'value' provided value is not None and iff is True"""
+        """Set a header 'name':'value'"""
         if value is not None and iff:
-            self.http_client.set_header(name, value)
+            self.headers[name] = unicode(value)
 
     def set_param(self, name, value=None, iff=True):
         if iff:
-            self.http_client.set_param(name, value)
-
-    def set_default_header(self, name, value):
-        self.http_client.headers.setdefault(name, value)
+            self.params[name] = unicode(value)
 
-    def request(self, method, path, **kwargs):
+    def request(
+            self, method, path,
+            async_headers=dict(), async_params=dict(),
+            **kwargs):
+        """Commit an HTTP request to base_url/path
+        Requests are commited to and performed by Request/ResponseManager
+        These classes perform a lazy http request. Present method, by default,
+        enforces them to perform the http call. Hint: call present method with
+        success=None to get a non-performed ResponseManager object.
+        """
+        assert isinstance(method, str) or isinstance(method, unicode)
+        assert method
+        assert isinstance(path, str) or isinstance(path, unicode)
         try:
+            headers = dict(self.headers)
+            headers.update(async_headers)
+            params = dict(self.params)
+            params.update(async_params)
             success = kwargs.pop('success', 200)
-
-            binary = kwargs.pop('binary', False)
             data = kwargs.pop('data', None)
-            self.set_default_header('X-Auth-Token', self.token)
-
+            headers.setdefault('X-Auth-Token', self.token)
             if 'json' in kwargs:
-                data = json.dumps(kwargs.pop('json'))
-                self.set_default_header('Content-Type', 'application/json')
+                data = dumps(kwargs.pop('json'))
+                headers.setdefault('Content-Type', 'application/json')
             if data:
-                self.set_default_header('Content-Length', unicode(len(data)))
+                headers.setdefault('Content-Length', '%s' % len(data))
 
-            self.http_client.url = self.base_url + path
-            r = self.http_client.perform_request(method=method, data=data)
+            plog = '\t[%s]' if self.LOG_PID else ''
+            sendlog.debug('\n\nCMT %s@%s%s', method, self.base_url, plog)
+            req = RequestManager(
+                method, self.base_url, path,
+                data=data, headers=headers, params=params)
+            #  req.log()
+            r = ResponseManager(
+                req, connection_retry_limit=self.CONNECTION_RETRY_LIMIT)
+            r.LOG_TOKEN, r.LOG_DATA, r.LOG_PID = (
+                self.LOG_TOKEN, self.LOG_DATA, self.LOG_PID)
+            r._token = headers['X-Auth-Token']
+        finally:
+            self.headers = dict()
+            self.params = dict()
 
-            req = self.http_client
-            sendlog.info('%s %s', method, req.url)
-            for key, val in req.headers.items():
-                sendlog.info('%s: %s', key, val)
-            sendlog.info('')
-            if data:
-                sendlog.info('%s', data)
-
-            recvlog.info('%d %s', r.status_code, r.status)
-            for key, val in r.headers.items():
-                recvlog.info('%s: %s', key, val)
-            recvlog.info('')
-            if r.content:
-                recvlog.debug(r.content)
-
-            if success is not None:
-                # Success can either be an in or a collection
-                success = (success,) if isinstance(success, int) else success
-                if r.status_code not in success:
-                    self._raise_for_status(r)
-        except Exception as err:
-            self.http_client.reset_headers()
-            self.http_client.reset_params()
-            if isinstance(err, HTTPConnectionError):
-                raise ClientError(message=err.message, status=err.status, details=err.details)
-            raise
-
-        self.http_client.reset_headers()
-        self.http_client.reset_params()
+        if success is not None:
+            # Success can either be an int or a collection
+            success = (success,) if isinstance(success, int) else success
+            if r.status_code not in success:
+                self._raise_for_status(r)
         return r
 
     def delete(self, path, **kwargs):
@@ -148,4 +492,3 @@ class Client(object):
 
     def move(self, path, **kwargs):
         return self.request('move', path, **kwargs)
-