This is the eighth part of the Twisted tutorial Twisted from Scratch, or The Evolution of Finger .
In this part, we add HTTPS support to our web frontend, showing how to have a single factory listen on multiple ports. More information on using SSL in Twisted can be found in the SSL howto .
All we need to do to code an HTTPS site is just write a context factory (in
this case, which loads the certificate from a certain file) and then use the
twisted.internet.endpoints.serverFromString method to build a SSL endpoint.
Note that one factory (in this case, a site) can listen on multiple ports with
multiple protocols.
Of course, this endpoint doesn’t work without a TLS certificate and a private key. You’ll need to create a self-signed cert and key. This will obviously not be trusted by your web browser, so you’ll see a warning when you connect. In this case, don’t worry: you’re not at risk.
To create a certificate and key that can be used by this tutorial, run the following:
openssl req -x509 -newkey rsa:2048 -keyout key.pem -out cert.pem -days 365
# Do everything properly, and componentize
import cgi
from zope.interface import Interface, implementer
from OpenSSL import SSL
from twisted.application import internet, service, strports
from twisted.internet import defer, endpoints, protocol, reactor
from twisted.protocols import basic
from twisted.python import components
from twisted.spread import pb
from twisted.web import resource, server, static, xmlrpc
from twisted.words.protocols import irc
class IFingerService(Interface):
def getUser(user):
"""
Return a deferred returning L{bytes}.
"""
def getUsers():
"""
Return a deferred returning a L{list} of L{bytes}.
"""
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 + b"\r\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.
"""
@implementer(IFingerFactory)
class FingerFactoryFromService(protocol.ServerFactory):
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 L{bytes}.
"""
def buildProtocol(addr):
"""
Return a protocol returning L{bytes}.
"""
@implementer(IFingerSetterFactory)
class FingerSetterFactoryFromService(protocol.ServerFactory):
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.encode("ascii"))
d.addErrback(catchError)
d.addCallback(lambda m: f"Status of {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.
"""
@implementer(IIRCClientFactory)
class IRCClientFactoryFromService(protocol.ClientFactory):
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 UserStatusTree(resource.Resource):
def __init__(self, service):
resource.Resource.__init__(self)
self.service = service
# add a specific child for the path "RPC2"
self.putChild("RPC2", UserStatusXR(self.service))
# need to do this for resources at the root of the site
self.putChild("", self)
def _cb_render_GET(self, users, request):
userOutput = "".join(
[f'<li><a href="{user}">{user}</a></li>' for user in users]
)
request.write(
"""
<html><head><title>Users</title></head><body>
<h1>Users</h1>
<ul>
%s
</ul></body></html>"""
% userOutput
)
request.finish()
def render_GET(self, request):
d = self.service.getUsers()
d.addCallback(self._cb_render_GET, request)
# signal that the rendering is not complete
return server.NOT_DONE_YET
def getChild(self, path, request):
return UserStatus(user=path, service=self.service)
components.registerAdapter(UserStatusTree, IFingerService, resource.IResource)
class UserStatus(resource.Resource):
def __init__(self, user, service):
resource.Resource.__init__(self)
self.user = user
self.service = service
def _cb_render_GET(self, status, request):
request.write(
"""<html><head><title>%s</title></head>
<body><h1>%s</h1>
<p>%s</p>
</body></html>"""
% (self.user, self.user, status)
)
request.finish()
def render_GET(self, request):
d = self.service.getUser(self.user)
d.addCallback(self._cb_render_GET, request)
# signal that the rendering is not complete
return server.NOT_DONE_YET
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.
"""
@implementer(IPerspectiveFinger)
class PerspectiveFingerFromService(pb.Root):
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
)
@implementer(IFingerService)
class FingerService(service.Service):
def __init__(self, filename):
self.filename = filename
self.users = {}
def _read(self):
self.users.clear()
with open(self.filename, "rb") as f:
for line in f:
user, status = line.split(b":", 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, b"No such user"))
def getUsers(self):
return defer.succeed(list(self.users.keys()))
def startService(self):
self._read()
service.Service.startService(self)
def stopService(self):
service.Service.stopService(self)
self.call.cancel()
application = service.Application("finger", uid=1, gid=1)
f = FingerService("/etc/users")
serviceCollection = service.IServiceCollection(application)
f.setServiceParent(serviceCollection)
strports.service("tcp:79", IFingerFactory(f)).setServiceParent(serviceCollection)
site = server.Site(resource.IResource(f))
strports.service(
"tcp:8000",
site,
).setServiceParent(serviceCollection)
strports.service(
"ssl:port=443:certKey=cert.pem:privateKey=key.pem", site
).setServiceParent(serviceCollection)
i = IIRCClientFactory(f)
i.nickname = "fingerbot"
internet.ClientService(
endpoints.clientFromString(reactor, "tcp:irc.freenode.org:6667"), i
).setServiceParent(serviceCollection)
strports.service(
"tcp:8889", pb.PBServerFactory(IPerspectiveFinger(f))
).setServiceParent(serviceCollection)