source: fedd/fedd.py @ c35207d

#!/usr/local/bin/python

import sys

from BaseHTTPServer import BaseHTTPRequestHandler

from ZSI import Fault, ParseException, FaultFromNotUnderstood, \
    FaultFromZSIException, FaultFromException, ParsedSoap, SoapWriter

from M2Crypto import SSL
from M2Crypto.SSL.SSLServer import ThreadingSSLServer
import xmlrpclib

from optparse import OptionParser

from fedd_util import fedd_ssl_context
from fedid import fedid
from fedd_deter_impl import new_feddservice
from fedd_services import ns0
from service_error import *

from threading import *
from signal import signal, pause, SIGINT, SIGTERM
from select import select, error
from time import sleep
import logging
from ConfigParser import *

# The SSL server here is based on the implementation described at
# http://www.xml.com/pub/a/ws/2004/01/20/salz.html

# Turn off the matching of hostname to certificate ID
SSL.Connection.clientPostConnectionCheck = None

class fedd_config_parser(SafeConfigParser):
    """
    A SafeConfig parser with a more forgiving get attribute
    """

    def safe_get(self, sect, opt, method, default=None):
        """
        If the option is present, return it, otherwise the default.
        """
        if self.has_option(sect, opt): return method(self, sect, opt)
        else: return default

    def get(self, sect, opt, default=None):
        """
        This returns the requested option or a given default.

        It's more like getattr than get.
        """

        return self.safe_get(sect, opt, SafeConfigParser.get, default)

    def getint(self, sect, opt, default=0):
        """
        Returns the selected option as an int or a default.
        """

        return self.safe_get(sect, opt, SafeConfigParser.getint, default)

    def getfloat(self, sect, opt, default=0.0):
        """
        Returns the selected option as an int or a default.
        """

        return self.safe_get(sect, opt, SafeConfigParser.getfloat, default)

    def getboolean(self, sect, opt, default=False):
        """
        Returns the selected option as a boolean or a default.
        """

        return self.safe_get(sect, opt, SafeConfigParser.getboolean, default)

class fedd_server(ThreadingSSLServer):
    """
    Interface the fedd services to the XMLRPC and SOAP interfaces
    """
    def __init__(self, ME, handler, ssl_ctx, impl):
        """
        Create an SSL server that handles the transport in handler using the
        credentials in ssl_ctx, and interfacing to the implementation of fedd
        services in fedd.  ME is the host port pair on which to bind.
        """
        ThreadingSSLServer.__init__(self, ME, handler, ssl_ctx)
        self.impl = impl
        self.soap_methods = impl.soap_services
        self.xmlrpc_methods = impl.xmlrpc_services
        self.log = logging.getLogger("fedd")

class fedd_soap_handler(BaseHTTPRequestHandler):
    """
    Standard connection between SOAP and the fedd services in impl.

    Much of this is boilerplate from 
    http://www.xml.com/pub/a/ws/2004/01/20/salz.html
    """
    server_version = "ZSI/2.0 fedd/0.1 " + BaseHTTPRequestHandler.server_version

    def send_xml(self, text, code=200):
        """Send an XML document as reply"""
        self.send_response(code)
        self.send_header('Content-type', 'text/xml; charset="utf-8"')
        self.send_header('Content-Length', str(len(text)))
        self.end_headers()
        self.wfile.write(text)
        self.wfile.flush()
        self.request.socket.close()

    def send_fault(self, f, code=500):
        """Send a SOAP encoded fault as reply"""
        self.send_xml(f.AsSOAP(processContents="lax"), code)

    def check_headers(self, ps):
        """Send a fault for any required envelope headers"""
        for (uri, localname) in ps.WhatMustIUnderstand():
            self.send_fault(FaultFromNotUnderstood(uri, lname, 'fedd'))
            return False
        return  True

    def check_method(self, ps):
        """Confirm that this class implements the namespace and SOAP method"""
        root = ps.body_root
        if root.namespaceURI not in self.server.impl.soap_namespaces:
            self.send_fault(Fault(Fault.Client, 
                'Unknown namespace "%s"' % root.namespaceURI))
            return False

        if getattr(root, 'localName', None) == None:
            self.send_fault(Fault(Fault.Client, 'No method"'))
            return False
        return True

    def do_POST(self):
        """Treat an HTTP POST request as a SOAP service call"""
        try:
            cl = int(self.headers['content-length'])
            data = self.rfile.read(cl)
            ps = ParsedSoap(data)
        except ParseException, e:
            self.send_fault(Fault(Fault.Client, str(e)))
            return
        except Exception, e:
            self.send_fault(FaultFromException(e, 0, sys.exc_info()[2]))
            return
        if not self.check_headers(ps): return
        if not self.check_method(ps): return
        try:
            resp = self.soap_dispatch(ps.body_root.localName, ps,
                    fedid(cert=self.request.get_peer_cert()))
        except Fault, f:
            self.send_fault(f)
            resp = None
        
        if resp != None:
            sw = SoapWriter()
            sw.serialize(resp)
            self.send_xml(str(sw))

    def log_request(self, code=0, size=0):
        """
        Log request to the fedd logger
        """
        self.server.log.info("Successful SOAP request code %d" % code)

    def soap_dispatch(self, method, req, fid):
        """
        The connection to the implementation, using the  method maps

        The implementation provides a mapping from SOAP method name to the
        method in the implementation that provides the service.
        """
        if self.server.soap_methods.has_key(method):
            try:
                return self.server.soap_methods[method](req, fid)
            except service_error, e:
                de = ns0.faultType_Def(
                        (ns0.faultType_Def.schema,
                            "FeddFaultBody")).pyclass()
                de._code=e.code
                de._errstr=e.code_string()
                de._desc=e.desc
                if  e.is_server_error():
                    raise Fault(Fault.Server, e.code_string(), detail=de)
                else:
                    raise Fault(Fault.Client, e.code_string(), detail=de)
        else:
            raise Fault(Fault.Client, "Unknown method: %s" % method)


class fedd_xmlrpc_handler(BaseHTTPRequestHandler):
    """
    Standard connection between XMLRPC and the fedd services in impl.

    Much of this is boilerplate from 
    http://www.xml.com/pub/a/ws/2004/01/20/salz.html
    """
    server_version = "ZSI/2.0 fedd/0.1 " + BaseHTTPRequestHandler.server_version

    def send_xml(self, text, code=200):
        """Send an XML document as reply"""
        self.send_response(code)
        self.send_header('Content-type', 'text/xml; charset="utf-8"')
        self.send_header('Content-Length', str(len(text)))
        self.end_headers()
        self.wfile.write(text)
        self.wfile.flush()
        # Make sure to close the socket when we're done
        self.request.socket.close()

    def do_POST(self):
        """Treat an HTTP POST request as an XMLRPC service call"""
        # NB: XMLRPC faults are not HTTP errors, so the code is always 200,
        # unless an HTTP error occurs, which we don't handle.

        resp = None
        data = None
        method = None
        cl = int(self.headers['content-length'])
        data = self.rfile.read(cl)

        try:
            params, method = xmlrpclib.loads(data)
        except xmlrpclib.ResponseError:
            data = xmlrpclib.dumps(xmlrpclib.Fault("Client", 
                "Malformed request"), methodresponse=True)

        if method != None:
            try:
                resp = self.xmlrpc_dispatch(method, params,
                            fedid(cert=self.request.get_peer_cert()))
                data = xmlrpclib.dumps((resp,), encoding='UTF-8', 
                        methodresponse=True)
            except xmlrpclib.Fault, f:
                data = xmlrpclib.dumps(f, methodresponse=True)
                resp = None

        self.send_xml(data)

    def log_request(self, code=0, size=0):
        """
        Log request to the fedd logger
        """
        self.server.log.info("Successful XMLRPC request code %d" % code)


    def xmlrpc_dispatch(self, method, req, fid):
        """
        The connection to the implementation, using the  method maps

        The implementation provides a mapping from XMLRPC method name to the
        method in the implementation that provides the service.
        """
        if self.server.xmlrpc_methods.has_key(method):
            try:
                return self.server.xmlrpc_methods[method](req, fid)
            except service_error, e:
                raise xmlrpclib.Fault(e.code_string(), e.desc)
        else:
            raise xmlrpclib.Fault(100, "Unknown method: %s" % method)

class fedd_opts(OptionParser):
    """Encapsulate option processing in this class, rather than in main"""
    def __init__(self):
        OptionParser.__init__(self, usage="%prog [opts] (--help for details)",
                version="0.1")

        self.set_defaults(host="localhost", port=23235, transport="soap",
                logfile=None, debug=0)

        self.add_option("-d", "--debug", action="count", dest="debug", 
                help="Set debug.  Repeat for more information")
        self.add_option("-f", "--configfile", action="store",
                dest="configfile", help="Configuration file (required)")
        self.add_option("-H", "--host", action="store", type="string",
                dest="host", help="Hostname to listen on (default %default)")
        self.add_option("-l", "--logfile", action="store", dest="logfile", 
                help="File to send log messages to")
        self.add_option("-p", "--port", action="store", type="int",
                dest="port", help="Port to listen on (default %default)")
        self.add_option("-s", "--service", action="append", type="string",
                dest="services",
                help="Service description: host:port:transport")
        self.add_option("-x","--transport", action="store", type="choice",
                choices=("xmlrpc", "soap"),
                help="Transport for request (xmlrpc|soap) (Default: %default)")
        self.add_option("--trace", action="store_const", dest="tracefile", 
                const=sys.stderr, help="Print SOAP exchange to stderr")

servers_active = True       # Sub-servers run while this is True
services = [ ]              # Service descriptions
servers = [ ]               # fedd_server instances instantiated from services
servers_lock = Lock()       # Lock to manipulate servers from sub-server threads

def shutdown(sig, frame):
    """
    On a signal, stop running sub-servers.  
    
    This is connected to signals below
    """
    global servers_active, flog

    servers_active = False
    flog.info("Received signal %d, shutting down" % sig);

def run_server(s):
    """
    Operate a subserver, shutting down when servers_active is false.

    Each server (that is host/port/transport triple) has a thread running this
    function, so each can handle requests independently.  They all call in to
    the same implementation, which must manage its own synchronization.
    """
    global servers_active   # Not strictly needed: servers_active is only read
    global servers          # List of active servers
    global servers_lock     # Lock to manipulate servers

    while servers_active:
        try:
            i, o, e = select((s,), (), (), 1.0)
            if s in i: s.handle_request()
        except error:
            # The select call seems to get interrupted by signals as well as
            # the main thread.  This essentially ignores signals in this
            # thread.
            pass

    # Done.  Remove us from the list
    servers_lock.acquire()
    servers.remove(s)
    servers_lock.release()

opts, args = fedd_opts().parse_args()

# Logging setup
flog = logging.getLogger("fedd")
ffmt = logging.Formatter("%(asctime)s %(name)s %(message)s",
        '%d %b %y %H:%M:%S')

if opts.logfile: fh = logging.FileHandler(opts.logfile)
else: fh = logging.StreamHandler(sys.stdout)

# The handler will print anything, setting the logger level will affect what
# gets recorded.
fh.setLevel(logging.DEBUG)

if opts.debug: flog.setLevel(logging.DEBUG)
else: flog.setLevel(logging.INFO)

fh.setFormatter(ffmt)
flog.addHandler(fh)



# Initialize the implementation
if opts.configfile != None: 
    try:
        config= fedd_config_parser()
        config.read(opts.configfile)
    except e:
        sys.exit("Cannot parse confgi file: %s" % e)
else: 
    sys.exit("--configfile is required")

try:
    impl = new_feddservice(config)
except RuntimeError, e:
    str = getattr(e, 'desc', None) or getattr(e,'message', None) or \
            "No message"
    sys.exit("Error configuring fedd: %s" % str)

if impl.cert_file == None:
    sys.exit("Must supply certificate file (probably in config)")

# Create the SSL credentials
ctx = None
while ctx == None:
    try:
        ctx = fedd_ssl_context(impl.cert_file, impl.trusted_certs, 
                password=impl.cert_pwd)
    except SSL.SSLError, e:
        if str(e) != "bad decrypt" or impl.cert_pwd != None:
            raise

# Walk through the service descriptions and pack them into the services list.
# That list has the form (transport (host, port)).
if opts.services:
    for s in opts.services:
        try:
            h, p, t  = s.split(':')
        except ValueError:
            sys.exit("Invalid services specification: %s" % s)

        if not h: h = opts.host
        if not p: p = opts.port
        if not t: h = opts.transport

        p = int(p)

        services.append((t, (h, p)))
else:
    services.append((opts.transport, (opts.host, opts.port)))

# Create the servers and put them into a list
for s in services:
    if s[0] == "soap":
        servers.append(fedd_server(s[1], fedd_soap_handler, ctx, impl))
    elif s[0] == "xmlrpc":
        servers.append(fedd_server(s[1], fedd_xmlrpc_handler, ctx, impl))
    else: flog.warning("Unknown transport: %s" % s[0])

#  Make sure that there are no malformed servers in the list
services = [ s for s in services if s ]

# Catch signals
signal(SIGINT, shutdown)
signal(SIGTERM, shutdown)

# Start the servers
for s in servers:
    Thread(target=run_server, args=(s,)).start()

# Main thread waits for signals
while servers_active:
    sleep(1.0)

#Once shutdown starts wait for all the servers to terminate.
while True:
    servers_lock.acquire()
    if len(servers) == 0: 
        servers_lock.release()
        flog.info("All servers exited.  Terminating")
        sys.exit(0)
    servers_lock.release()
    sleep(1)