Introduction
This is the eleventh part of the Twisted tutorial Twisted from Scratch, or The Evolution of Finger.
In this part, we make it easier for non-programmers to configure a finger server, and show how to package it in the .deb and RPM package formats.
Plugins
So far, the user had to be somewhat of a programmer to be able to configure stuff. Maybe we can eliminate even that? Move old code to finger/__init__.py and...
Full source code for finger module here:
# finger.py module from zope.interface import Interface, implements from twisted.application import internet, service, strports from twisted.internet import protocol, reactor, defer from twisted.words.protocols import irc from twisted.protocols import basic from twisted.python import components from twisted.web import resource, server, static, xmlrpc, microdom from twisted.web.woven import page, model, interfaces from twisted.spread import pb from OpenSSL import SSL import cgi class IFingerService(Interface): def getUser(user): """Return a deferred returning a string""" def getUsers(): """Return a deferred returning a list of strings""" class IFingerSetterService(Interface): def setUser(user, status): """Set the user's status to something""" def catchError(err): return "Internal error in server" class FingerProtocol(basic.LineReceiver): def lineReceived(self, user): d = self.factory.getUser(user) d.addErrback(catchError) def writeValue(value): self.transport.write(value+'\n') self.transport.loseConnection() d.addCallback(writeValue) class IFingerFactory(Interface): def getUser(user): """Return a deferred returning a string""" def buildProtocol(addr): """Return a protocol returning a string""" class FingerFactoryFromService(protocol.ServerFactory): implements(IFingerFactory) protocol = FingerProtocol def __init__(self, service): self.service = service def getUser(self, user): return self.service.getUser(user) components.registerAdapter(FingerFactoryFromService, IFingerService, IFingerFactory) class FingerSetterProtocol(basic.LineReceiver): def connectionMade(self): self.lines = [] def lineReceived(self, line): self.lines.append(line) def connectionLost(self, reason): if len(self.lines) == 2: self.factory.setUser(*self.lines) class IFingerSetterFactory(Interface): def setUser(user, status): """Return a deferred returning a string""" def buildProtocol(addr): """Return a protocol returning a string""" class FingerSetterFactoryFromService(protocol.ServerFactory): implements(IFingerSetterFactory) protocol = FingerSetterProtocol def __init__(self, service): self.service = service def setUser(self, user, status): self.service.setUser(user, status) components.registerAdapter(FingerSetterFactoryFromService, IFingerSetterService, IFingerSetterFactory) class IRCReplyBot(irc.IRCClient): def connectionMade(self): self.nickname = self.factory.nickname irc.IRCClient.connectionMade(self) def privmsg(self, user, channel, msg): user = user.split('!')[0] if self.nickname.lower() == channel.lower(): d = self.factory.getUser(msg) d.addErrback(catchError) d.addCallback(lambda m: "Status of %s: %s" % (msg, m)) d.addCallback(lambda m: self.msg(user, m)) class IIRCClientFactory(Interface): """ @ivar nickname """ def getUser(user): """Return a deferred returning a string""" def buildProtocol(addr): """Return a protocol""" class IRCClientFactoryFromService(protocol.ClientFactory): implements(IIRCClientFactory) protocol = IRCReplyBot nickname = None def __init__(self, service): self.service = service def getUser(self, user): return self.service.getUser(user) components.registerAdapter(IRCClientFactoryFromService, IFingerService, IIRCClientFactory) class UsersModel(model.MethodModel): def initialize(self, *args, **kwargs): self.service=args[0] def wmfactory_users(self, request): return self.service.getUsers() components.registerAdapter(UsersModel, IFingerService, interfaces.IModel) class UserStatusTree(page.Page): template = """<html><head><title>Users</title></head><body> <h1>Users</h1> <ul model="users" view="List"> <li pattern="listItem"><a view="Anchor" /></li> </ul></body></html>""" def initialize(self, *args, **kwargs): self.service=args[0] def getDynamicChild(self, path, request): return UserStatus(user=path, service=self.service) def wchild_RPC2 (self, request): return UserStatusXR(self.service) components.registerAdapter(UserStatusTree, IFingerService, resource.IResource) class UserStatus(page.Page): template='''<html><head><title view="Text" model="user"/></head> <body><h1 view="Text" model="user"/> <p model="status" view="Text" /> </body></html>''' def initialize(self, **kwargs): self.user = kwargs['user'] self.service = kwargs['service'] def wmfactory_user(self, request): return self.user def wmfactory_status(self, request): return self.service.getUser(self.user) class UserStatusXR(xmlrpc.XMLRPC): def __init__(self, service): xmlrpc.XMLRPC.__init__(self) self.service = service def xmlrpc_getUser(self, user): return self.service.getUser(user) def xmlrpc_getUsers(self): return self.service.getUsers() class IPerspectiveFinger(Interface): def remote_getUser(username): """return a user's status""" def remote_getUsers(): """return a user's status""" class PerspectiveFingerFromService(pb.Root): implements(IPerspectiveFinger) def __init__(self, service): self.service = service def remote_getUser(self, username): return self.service.getUser(username) def remote_getUsers(self): return self.service.getUsers() components.registerAdapter(PerspectiveFingerFromService, IFingerService, IPerspectiveFinger) class FingerService(service.Service): implements(IFingerService) def __init__(self, filename): self.filename = filename self._read() def _read(self): self.users = {} for line in file(self.filename): user, status = line.split(':', 1) user = user.strip() status = status.strip() self.users[user] = status self.call = reactor.callLater(30, self._read) def getUser(self, user): return defer.succeed(self.users.get(user, "No such user")) def getUsers(self): return defer.succeed(self.users.keys()) class ServerContextFactory: def getContext(self): """Create an SSL context. This is a sample implementation that loads a certificate from a file called 'server.pem'.""" ctx = SSL.Context(SSL.SSLv23_METHOD) ctx.use_certificate_file('server.pem') ctx.use_privatekey_file('server.pem') return ctx # Easy configuration def makeService(config): # finger on port 79 s = service.MultiService() f = FingerService(config['file']) h = internet.TCPServer(79, IFingerFactory(f)) h.setServiceParent(s) # website on port 8000 r = resource.IResource(f) r.templateDirectory = config['templates'] site = server.Site(r) j = internet.TCPServer(8000, site) j.setServiceParent(s) # ssl on port 443 # if config.get('ssl'): # k = internet.SSLServer(443, site, ServerContextFactory()) # k.setServiceParent(s) # irc fingerbot if config.has_key('ircnick'): i = IIRCClientFactory(f) i.nickname = config['ircnick'] ircserver = config['ircserver'] b = internet.TCPClient(ircserver, 6667, i) b.setServiceParent(s) # Pespective Broker on port 8889 if config.has_key('pbport'): m = internet.TCPServer( int(config['pbport']), pb.PBServerFactory(IPerspectiveFinger(f))) m.setServiceParent(s) return s
# finger/tap.py from twisted.application import internet, service from twisted.internet import interfaces from twisted.python import usage import finger class Options(usage.Options): optParameters = [ ['file', 'f', '/etc/users'], ['templates', 't', '/usr/share/finger/templates'], ['ircnick', 'n', 'fingerbot'], ['ircserver', None, 'irc.freenode.net'], ['pbport', 'p', 8889], ] optFlags = [['ssl', 's']] def makeService(config): return finger.makeService(config)
And register it all:
#finger/plugins.tml register('finger', 'finger.tap', description='Build a finger server tap', type='tap', tapname='finger')
And now, the following works
% mktap finger --file=/etc/users --ircnick=fingerbot % sudo twistd -nf finger.tap
OS Integration
If we already have the finger
package installed in
PYTHONPATH (e.g. we added it to site-packages), we can achieve easy
integration:
Debian
% tap2deb --unsigned -m "Foo <foo@example.com>" --type=python finger.tac % sudo dpkg -i .build/*.deb
Red Hat / Mandrake
% tap2rpm --type=python finger.tac #[maybe other options needed] % sudo rpm -i .build/*.rpm
Will properly register the tap/tac, init.d scripts, etc. for the given file.
If it doesn't work on your favorite OS: patches accepted!