#!/usr/bin/python2.2
from slides import Slide, Bullet, SubBullet, URL, Image, PRE
from twslides import Lecture
class PythonSource:
def __init__(self, content):
self.content = content
def toHTML(self):
return '<pre class="python">%s</pre>' % (self.content,)
class Raw:
def __init__(self, content):
self.content = content
def toHTML(self):
return self.content + '\n'
lecture = Lecture(
"Applications of Twisted",
Slide("Twisted.names",
Bullet("Domain Name Server", SubBullet(
Bullet("Authoritative"),
Bullet("Caching"),
Bullet("Other!"),
)),
Bullet("Domain Name Client"),
),
Slide("Mostly Functional",
Bullet("All common records support; 22 supported total", SubBullet(
Bullet("A, NS, CNAME, SOA, PTR, HINFO, MX, TXT"),
Bullet("IPv6 records AAAA and A6"),
)),
Bullet("No DNSSEC support"),
Bullet("Server and Client functionality"),
),
Slide("Rapidly Developed",
Bullet("One month initial development period", SubBullet(
Bullet("Python is good for rapid development"),
Bullet("Twisted handles all the boring network details"),
)),
Bullet("Easily extended", SubBullet(
Bullet("Doesn't choke on unrecognized record types"),
Bullet("Support for a new record type can be added in "
"just a few minutes"),
Bullet(PythonSource("""\
from twisted.protocols import dns
class Record_A:
__implements__ = (dns.IEncodable,)
TYPE = dns.QUERY_TYPES['A'] = 1
def __init__(self, address = '0.0.0.0'):
self.address = socket.inet_aton(address)
def encode(self, strio, compDict = None):
strio.write(self.address)
def decode(self, strio, length = None):
self.address = readPrecisely(strio, 4)
"""
)),
)),
),
Slide("Easily Configured",
Bullet("BIND zonefile syntax"),
Bullet("Python source", SubBullet(
Bullet(PythonSource("""\
zone = [
AAAA('intarweb.us', '3ffe:b80:1886:1::1'),
SRV('_http._tcp.www.intarweb.us', 0, 0, 8080, 'intarweb.us'),
MX('intarweb.us', 10, 'mail.intarweb.us')
]
"""
)),
)),
Bullet("Twisted's mktap and twistd tools", SubBullet(
PRE("mktap dns --pyzone a.domain.zonefile --recursive --cache"),
PRE("twistd -f dns.tap"),
)),
),
Slide("Client API",
Bullet("Asynchronous", SubBullet(
Bullet("All lookup functions return Deferred objects"),
Bullet(PythonSource(
"""\
import random
from twisted.names import client
def addressFor(service, protocol, domain):
d = client.theResolver.lookupService(
'_%s._%s.%s' % (service, protocol, domain)
)
def grabPayload((answers, authority, additional)):
return [r.payload for r in answers]
def randomAnswer(results):
if len(results) == 1 and results[0] == '.':
raise RuntimeException, "No service records found"
return random.choice(results)
return d.addCallback(grabPayload).addCallback(randomAnswer)
"""
)),
)),
),
Slide("Uses",
Bullet("Service Records", SubBullet(
Bullet("Potential to simplify user experience"),
Bullet("Not widely accessible"),
Bullet("Names' client API makes accessing them trivial"),
)),
),
Slide("Pynfo: A Network Information 'Bot",
Bullet("A 'bot with the goal of integrating access to miscellaneous data inputs"),
),
Slide("Architecture",
Bullet("Factories", SubBullet(
Bullet("Takes care of connecting to different services"),
Bullet("Acts as a central storage for shared data"),
Bullet("Currently only IRC is supported"),
Bullet("Planned support for web, IM, and PB interfaces")
)),
Bullet("Protocols", SubBullet(
Bullet("Created by Factories"),
Bullet("Handles all service-specific interaction"),
Bullet("Refers back to the factory for shared data"),
Bullet("Current support for IRC only")
)),
Image("pynfo-chart.png"),
Bullet("Separation of Factory and Protocols", SubBullet(
Bullet("Per-protocol data separate, per-robot data shared"),
Bullet("Protocols destroyed on disconnect, factory manage reconnecting"),
)),
),
Slide("Plugins",
Bullet("Plugins are modules plus some metadata", SubBullet(
Bullet("A plugin name"),
Bullet("A plugin description"),
Bullet("A plugin type"),
Bullet("Any other data appropriate for the type"),
)),
Bullet("Initialization / Finalization hooks"),
Bullet("Input filtering, for behaviors like ignore"),
Bullet("An example", SubBullet(
Bullet(PythonSource("""
from twisted.names import client
def info_LOOKUP(bot, user, channel, query):
def tellUserResponse((ans, auth, add)):
bot.reply(user, "%s: %s" % (query, [str(a.payload) for a in ans]))
def tellUserError(failure):
bot.reply(user, "Host lookup failed.")
client.lookupAddress(query).addCallbacks(
tellUserResponse, tellUserError
)
"""
)),
)),
),
Slide("But where do they come from?",
Bullet("Twisted's plugin module", SubBullet(
Bullet(PythonSource("""\
from twisted.python import plugin
class InfoBotFactory:
...
def loadPlugins(self):
...
p = plugin.getPlugIns('infobot')
....
"""
)),
)),
),
Slide("Persistence",
Bullet("Addresses to connect to and protocols to use"),
Bullet("Administrators, passwords, keys"),
Bullet("Connection statistics"),
Bullet("Plugins can store objects for later retrieval")
),
Slide("Components",
Bullet("Shared and pluggable behavior is implemented as Adapters for Interfaces", SubBullet(
Bullet("IScheduler, IStorage, IAuthenticator"),
)),
Bullet("Plugins can register their own adapters for the factory", SubBullet(
Bullet("Gracefully add new capabilities without __class__ hacks"),
Bullet("Share capabilities with other plugins"),
Bullet("Avoids namespace collisions"),
)),
),
Slide("Interaction",
Bullet("Commands and responses are issued through normal protocol actions"),
Bullet('Three levels of command "security"'),
Bullet("Access to some commands is unrestricted",
Raw("<code>"),
SubBullet("<exarkun> pyn: networks"),
SubBullet("<pyn> Connected to: oftc -> ('irc.oftc.net', 6667), fn -> ('irc.freenode.net', 6667)"),
Raw("</code>"),
),
Bullet("Access to others is granted via an ACL",
Raw("<code>"),
SubBullet("<exarkun> pyn: rebuild"),
SubBullet("<pyn> You aren't allowed to do that."),
Raw("</code>"),
),
Bullet("Still further access is granted by the possession of a secret key",
Raw("<code>"),
SubBullet("<exarkun> pyn: spill self.transport.getHost()"),
SubBullet("<pyn> Command queued. Challenge: BBKSkYCRCGQETx4kTmceUg==%"),
SubBullet("<exarkun> pyn: respond 2lwcgSVnJPzrW6Yvq7sg+g==%"),
SubBullet("<pyn> ('INET', '192.168.123.137', 45539)"),
Raw("</code>"),
)
),
Slide("Network Bridging",
Bullet("Pass messages between networks",
Raw("<code>"),
SubBullet("<pyn> Yosomono (~fake@hostmask) has joined on efnet"),
SubBullet("<pyn> <Yosomono@efnet> hello"),
Raw("</code>"),
),
Bullet("Requesting user information across networks",
Raw("<code>"),
SubBullet("<exarkun> pyn: whois Yosomono@efnet"),
SubBullet("<pyn> Hostmask: Yosomono!fake@hostmask"),
SubBullet("<pyn> Channels: @#python"),
Raw("</code>"),
),
),
Slide("Conversation Logging",
Bullet("The 'conversation' command", SubBullet(
Raw("<code>"),
SubBullet("<exar[con]> pyn: conversation begin PyCon example conversation"),
SubBullet("<pyn> Beginning tagged conversation 'PyCon example conversation'."),
SubBullet("<exar[con]> Hello, PyCon"),
SubBullet("<exar[con]> Enjoy the example!"),
SubBullet("<exar[con]> pyn: conversation end PyCon example conversation"),
SubBullet("<pyn> Ended tagged conversation 'PyCon example conversation'."),
Raw("</code>"),
)),
Bullet("Web interface", SubBullet(
URL("http://c.intarweb.us:8008/%23tanstaafl/PyCon%20example%20conversation"),
)),
Bullet("Search previous logs and add conversation tags"),
),
Slide("Various other plugins",
Bullet("PyPI monitor and querying"),
Bullet("Network specific operations - IRC operator module"),
Bullet("Freshmeat and Google querying"),
Bullet("Link shortener"),
Bullet("PyMetar plugin"),
Bullet("Manhole"),
),
Slide("Questions?"),
)
lecture.renderHTML(".", "applications-%d.html", css="stylesheet.css")