__init__.py

import traceback
import sys
import os
import socket
import logging
from pynimbusauthz.cmd_opts import cbOpts
from cbPosixSecurity import cbPosixSec
from cbPosixBackend import cbPosixBackend
from ConfigParser import SafeConfigParser
from pycb.cbAuthzSecurity import cbAuthzUser
from pycb.cbAuthzSecurity import cbAuthzSec
import random
from optparse import OptionParser
import hmac
try:
    from hashlib import sha1 as sha
    from hashlib import sha256 as sha256
except ImportError:
    import sha
import boto
import boto.utils
import base64

Version = "0.1"
logger = None
authenticated_user_id = "CumulusAuthenticatedUser"
public_user_id = "CumulusPublicUser"

def log(level, msg, tb=None):
    global logger

    if logger == None:
        print msg
        return

    logger.log(level, msg)

    if tb != None:
        logger.log(level, "Stack trace")
        logger.log(level, "===========")
        stack = tb.format_exc()
        logger.log(level, stack)
        logger.log(level, "===========")
        logger.log(level, sys.exc_info()[0])

class CBConfig(object):

    def __init__(self):
        self.default_settings()
        self.load_settings()

        conf_err_msg = ""
        config_error = False
        if self.auth == None:
            config_error = True
            conf_err_msg = "No authentication module set: |%s|" % (self.auth_error)

        if self.bucket == None:
            config_error = True
            conf_err_msg = conf_err_msg + " No backend set"

        if self.installdir == None:
            config_error = True
            conf_err_msg = conf_err_msg + " No install dir set"

        if config_error:
            msg = """cumulus.ini file must have the following set:
installdir=<path to cumulus installation>

The search path for cumulus.ini is:

    /etc/nimbus/cumulus.ini
    $CUMULUS_HOME/etc/cumulus.ini
    ~/.nimbus/cumulus.ini
    cumulus.ini
    env 'CUMULUS_SETTINGS_FILE
"""
            raise Exception(msg + "\n" + conf_err_msg)

        self.setup_logger()

    def setup_logger(self):
        global logger
        if self.log_filename == None:
            self.log_filename = self.installdir + "/log/cumulus.log"

        logger = logging.getLogger('cumulus')
        handler = logging.handlers.RotatingFileHandler(
          self.log_filename, maxBytes=100*1024*1024, backupCount=2)
        logger.addHandler(handler)
        logger.setLevel(self.log_level)
        formatter = logging.Formatter("%(asctime)s - %(process)d - %(levelname)s - %(message)s")
        handler.setFormatter(formatter)
        logger.addHandler(handler)

    def default_settings(self):
        self.auth_error = ""
        self.hostname = socket.gethostname()
        self.installdir = None
        self.port = 8888
        self.auth = None
        self.bucket = None
        self.log_level = logging.INFO
        self.log_filename = None
        self.location = "CumulusLand"
        self.https_key = None
        self.https_cert = None
        self.use_https = False
        self.block_size = 1024*512
        self.lb_file = None
        self.lb_max = 0
        self.redirector = cbRedirectorIface()

    def get_contact(self):
        return (self.hostname, self.port)

    def load_settings(self):
        config_path = []
        config_path.append("/etc/nimbus/cumulus.ini")
        if 'CUMULUS_HOME' in os.environ:
            config_path.append(os.path.join(os.environ['CUMULUS_HOME'], "etc/cumulus.ini"))
        config_path.append(os.path.expanduser('~/.nimbus/cumulus.ini'))
        config_path.append(os.path.expanduser('cumulus.ini'))
        config_path.append(os.environ.get('CUMULUS_SETTINGS_FILE'))
        log_levels = {'debug': logging.DEBUG,
            'info': logging.INFO,
            'warning': logging.WARNING,
            'error': logging.ERROR,
            'critical': logging.CRITICAL}

        for cp in config_path:
            try:
                s = SafeConfigParser()
                s.readfp(open(cp, "r"))
            except:
                continue

            try:
                self.installdir = s.get("cb", "installdir")
            except:
                pass
            try:
                self.port = int(s.get("cb", "port"))
            except:
                pass
            try:
                self.hostname = s.get("cb", "hostname")
            except:
                pass
            try:
                self.location = s.get("cb", "location")
            except:
                pass

            try:
                backend = s.get("backend", "type")
                if backend == "posix":
                    posix_dir = s.get("backend", "data_dir")
                    self.bucket = cbPosixBackend(posix_dir)
                    block_size = s.get("backend", "block_size")
            except:
                pass

            try:
                sec = s.get("security", "type")
                self.sec_type = sec
                if sec == "posix":
                    posix_dir = s.get("security", "security_dir")
                    self.auth = cbPosixSec(posix_dir)
                elif sec == "authz":
                    self.authzdb = s.get("security", "authzdb")
                    self.auth = cbAuthzSec(self.authzdb)
                else:
                    self.auth_error = self.auth_error + "no type %s" % (sec)
            except:
                traceback.print_exc(file=sys.stderr)
                x = str(sys.exc_info()[0])
                self.auth_error = x + self.auth_error

            try:
                log_level_str = s.get("log", "level")
                self.log_level = log_levels[log_level_str]
            except Exception, ex:
                pass
            try:
                self.log_filename = s.get("log", "file")
            except:
                pass

            try:
                self.https_key = s.get("https", "key").strip()
                self.https_cert = s.get("https", "cert").strip()
                self.use_https = s.getboolean("https", "enabled")
            except:
                pass

            try:
                self.lb_file = s.get("load_balanced", "hostfile")
                self.lb_max = int(s.get("load_balanced", "max"))
            except:
                pass

            try:
                redirector_name = s.get("redirector", "type")
                if redirector_name == "basic":
                    self.redirector = cbBasicRedirector(s)
            except:
                pass


    def parse_cmdline(self, argv):
        global Version

        self.opts = []
        opt = cbOpts("port", "p", "use the give port number", None, range=(0, 65536))
        self.opts.append(opt)
        opt = cbOpts("https", "s", "Enable https", False, flag=True)
        self.opts.append(opt)

        u = """ [options]"""
    
        version = "%prog " + (Version)
        parser = OptionParser(usage=u, version=version)
        for o in self.opts:
            o.add_opt(parser)

        (options, args) = parser.parse_args(args=argv)

        for o in self.opts:
            o.validate(options)

        # override anything from the files        
        if options.port != None:
            self.port = int(options.port)


def get_auth_hash(key, method, path, headers, uri):

    sub_resources = ["?acl", "?location", "?logging", "?torrent"]
    for sr in sub_resources:
        ndx = uri.find(sr)
        if ndx > 0:
            path = path + sr

    myhmac = hmac.new(key, digestmod=sha)
    c_string = boto.utils.canonical_string(method, path, headers)
    myhmac.update(c_string)
    auth_hash = base64.encodestring(myhmac.digest()).strip()
    return auth_hash

config = CBConfig()

# this is not a long term solution
def get_next_host():
    if not config.lb_file:
        return None

    try:
        hosts = []
        f = open(config.lb_file, "r")
        for l in f.readlines():
            hosts.append(l.strip())
        f.close()

        my_host = "%s:%d" % (config.hostname, config.port)

        for i in range(0, 10):
            ndx = random.randint(0, len(hosts)-1)
            h = hosts[ndx]
            if h != my_host:
                return h
        return h
    except Exception, ex:
        log(logging.ERROR, "get next host error %s" % (str(ex)))
        return None