Mailman 3 - Twisted-web

Twisted HTTPS Server-Client Communication problem
by Ohad Shai 22 Oct '17

22 Oct '17

Hi, I have an important question about twisted HTTPS client-server communication. I ran an HTTPS server with my own certs and tried to communicate with a twisted HTTPS client with the specific cert. I am getting an error that says: "Invalid DNS-ID". all the error info with all my code is in here: https://gist.github.com/anonymous/e46d4d8dc1c102857497cde9e2fc4725#file-gis… Twisted-HTTPS-client-server<https://gist.github.com/anonymous/e46d4d8dc1c102857497cde9e2fc4725#file-gis…> gist.github.com Twisted-HTTPS-client-server I will be appreciate if someone has a clue how can I fix this error. Thanks, Ohad Shai Software Engineer, EDR Linux 972-052-6887792 ohad.shai(a)cyberbit.com<mailto:daniel.doron@cyberbit.com>

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IPolicyForHTTP supporting cert based mutual auth
by Jason Litzinger 12 Sep '17

12 Sep '17

Recently, I had to implement a client that supported cert based mutual auth. I searched a bit in both Twisted and treq but didn't find an existing implementation (maybe I missed it), so I implemented a custom IPolicyForHTTPS. It was pretty easy, and though it needs more testing, seems to be working well. My question is whether this would be of interest as a PR to Twisted itself (or a project under that umbrella)? The use case comes to mind is IoT (though it isn't the only one), and a specific example is the AWS IoT API: http://docs.aws.amazon.com/iot/latest/developerguide/authorization.html Cheers, -Jason Litzinger

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Python and Cors
by Deve Krehbiel 27 Aug '17

27 Aug '17

First post so forgive me if I am not explaining this right. I am trying to make a baby cam and then heavily document it for everyone to have access to. I am using a Raspberry Pi with Rasbian. I am using mjpg-streamer for the streaming with no problems. The problem is I am also using two servos for pan and tilt. To accomplish this I am using an Arduino Uno. This is so I can add IR lighting for night vision, etc later. I am not a programmer so this is getting frustrating after a few weeks of failure. How is it failing you might ask..well, its working perfectly with only ONE exception: Every time I push the button for left/right/up/down I get this: XMLHttpRequest cannot load http://192.168.1.122:81/servos.rpy?value=100P. No 'Access-Control-Allow-Origin' header is present on the requested resource. Origin 'http://192.168.1.122:9000' is therefore not allowed access. On the local area network, it still works, but taking it to the internet it does not. Here are the two programs that make this happen. One is servos.rpy and the other is the supporting HTML/Get script; **** servos.rpy ----------------------------------- # Import necessary files import serial from twisted.web.resource import Resource # Setup Arduino at correct speed try: arduino = serial.Serial('/dev/ttyACM0', 9600) except: arduino = serial.Serial('/dev/ttyACM1', 9600) class MoveServo(Resource): isLeaf = True def render_GET(self,request): try: # Send value over serial to the Arduino arduino.write(request.args['value'][0]) return 'Success' except: return 'Failure' resource = MoveServo() *** Now for the HTML/Get script: ** <!doctype html> <html> <head> <title>Make Use Of DIY Security Camera</title> <style type="text/css"> #container { /* center the content */ margin: 0 auto; text-align: center; } </style> </head> <body> <div id="container"> <img src="/?action=stream" /><br> <script src=" https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script><br /> <button onclick="servos.move('P', 10)">Left</button> <button onclick="servos.move('P', -10)">Right</button> <button onclick="servos.move('T', -10)">Down</button> <button onclick="servos.move('T', 10)">Up</button> </div> </body> <script> var servos; $( document ).ready(function() { servos = moveServos(); }); function moveServos() { // Store some settings, adjust to suit var panPos = 70, tiltPos = 90, tiltMax = 170, tiltMin = 45, panMax = 170, panMin = 20; return { move:function(servo, adjustment) { var value; if(servo == 'P') { if(!((panPos >= panMax && adjustment > 0) || (panPos <= panMin && adjustment < 0))) { // Still within allowed range, "schedule" the movement panPos += adjustment; } value = panPos + 'P'; } else if(servo == 'T') { if(!((tiltPos >= tiltMax && adjustment > 0) || (tiltPos <= tiltMin && adjustment < 0))) { // Still within allowed range, "schedule" the movement tiltPos += adjustment; } value = tiltPos + 'T'; } // Use AJAX to actually move the servo $.get('http://192.168.1.122:81/servos.rpy?value=' + value); }, } } </script> </html> ***** Twisted is started: sudo twistd -n web -p 81 --path /usr/local/www/ I would be forever grateful if someone could take a serious look at this and tell me where I am going wrong. Once this is fixed, I can start documenting the entire system for everyone. Thank you! Deve

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Nevow 0.14.3rc1 released
by Tristan Seligmann 19 Aug '17

19 Aug '17

Hi all, I've uploaded a prerelease of Nevow 0.14.3 to PyPI[1]. This contains a fix for some Athena client-side timeout behaviour (or more specifically, the lack of one) and removes use of FilePath.getmtime. If you are using Athena, please a) let me know! and b) give this prerelease a try to see if anything breaks. As the de facto Nevow release manager, and one of its last users, I'd like to avoid going overboard on release engineering if it isn't necessary, but I'd also like to avoid making life worse for any other remaining users, so it would be useful to hear from any of you out there still using Nevow. [1] https://pypi.python.org/pypi/Nevow/0.14.3rc1

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Status for me implementing connection upgrade for the twisted.web.client.Agent.
by Mike Mestnik 04 Aug '17

04 Aug '17

I've started working with twisted git, not the old twisted-web. Current patch https://github.com/cheako/twisted/commit/969ea0bced7048a922efd4999fde951e6b… I'm lost trying to find where Response is created so I can remove the connection from the pool.

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Support for websockets.
by Mike Mestnik 04 Aug '17

04 Aug '17

I was working on Tor2web, a client of twisted web. I discover that to move forward I'd need [iResponce](https://github.com/racker/python-twisted-web/blob/master/twisted… to expose the socket or something to read/write on. Once it's necessary to edit twisted-web I might as well go all out and at least partially implement Websockets. Here is what I did for [Tor2web](https://pastebin.com/MbHVvwNz) It's incomplete, I was reading twisted-web and discovered the masked interface. Here is a [good reference for Websockets](https://developer.mozilla.org/en-US/docs/Web/API/WebSockets_API… at a protocol level, it does say server but if you'r not working in Javascript this is the document u need to read. Here is what I'd envision for an interface, knowing only a little Python and almost no twisted. 1. Upon receiving the response headers indicating a change of protocol(connection: upgrade). Remove the socket from any connection pool, as it can't ever be used for http. The connection will be upgraded until it's closed. 2. Expose a socket interface in the iResponse class, it could be the class itself or an attribute. This could be a copy of the twisted socket interface or even that interface itself. With at least. a. onRead callback. b. Write. c. Close. d. onClose callback. e. onError, ect. The api does not NEED a method to determine if the connection was upgraded, since the headers indicate as much. However to prevent attempts to access the Websocket API when it's not available a python(ish) method for detecting as much I'll leave to your discretion. Thank you.

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Looks like a whitespace bug.
by Mike Mestnik 04 Aug '17

04 Aug '17

See: https://github.com/racker/python-twisted-web/commit/c58ea9b3f192106c3e3d1c1…

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Question regarding custom contextFactory for twisted.web.client.Agent
by Jason Litzinger 06 Jul '17

06 Jul '17

Hello, I have an optimization question in the realm of "before I do something foolish..." regarding the contextFactory passed to twisted.web.client.Agent. Background: I have (several) twisted applications running on a Cortex-A5 system, one of which interfaces with a web service using the twisted.web.client.Agent API*. The problem I've observed is that requests to this web service result in a higher than desired CPU load. To understand the source of the load I isolated the server interactions and profiled. Investigation: The profile data revealed the load in question stemmed from TLS related calls, specifically optionsForClientTLS, which is called once per connection. In looking (briefly) at what optionsForClientTLS does, it seemed (perhaps wrongly) that there was an opportunity for optimization in my specific case. The optimization is to create a custom contextFactory that caches the connection creator since the host is not changing. I prototyped an implementation and the load was reduced by a factor of ten. Question: Is it safe/sane to reuse a connection creator if the host to which I'm connecting is not going to change? Thanks, -Jason Litzinger * Technically this code is inside an open source third party SDK, but were I in their shoes I'd write it the same way, so I've no issues with their implementation.

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[ANN] txkube 0.1.0
by Jean-Paul Calderone 10 Apr '17

10 Apr '17

Hello all, I'm pleased to announce the first release of txkube, a Twisted-based library for interacting with Kubernetes using the HTTP API. This release supports several of the most commonly used basic Kubernetes objects, including Services, ConfigMaps, Deployments, ReplicaSets, and Pods. While Kubernetes has many, many more object kinds, this collection of kinds already supports a very useful set of interactions. Here is an example of txkube usage, taken from the README: from __future__ import print_function from twisted.internet.task import react from txkube import v1, network_kubernetes_from_context @react def main(reactor): k8s = network_kubernetes_from_context(reactor, u"minikube") client = k8s.client() d = client.list(v1.Namespace) d.addCallback(print) return d You can download txkube from PyPI <https://pypi.python.org/pypi> ( https://pypi.python.org/pypi). You can contribute to its development on GitHub <https://github.com/LeastAuthority/txkube> ( https://github.com/LeastAuthority/txkube). Thanks to Least Authority Enterprises <https://leastauthority.com/> ( https://leastauthority.com/) for sponsoring this development. Jean-Paul Calderone http://as.ynchrono.us/

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[ANN] txAWS 0.3.0
by Jean-Paul Calderone 10 Apr '17

10 Apr '17

Hello all, I'm pleased to announce the release of txAWS 0.3.0. txAWS is a library for interacting with Amazon Web Services (AWS) using Twisted. You can download the release from PyPI <https://pypi.python.org/pypi/txAWS> (https://pypi.python.org/pypi/txAWS). txAWS development uses GitHub for issues and source control <https://github.com/twisted/txaws> (https://github.com/twisted/txaws). Since the last release, the following enhancements have been made: - Jean-Paul Calderone added basic Route53 support. - Mark Williams add Auth v4, now used by the S3 and Route53 support. - Francisco Souza added support for VPCs to some EC2 APIs. - Drew Smathers added multi-part S3 upload support. - Several people added other S3 client features such as pagination and streaming uploads. - *txaws.testing* now provides S3 and Route53 support. Additionally, the following APIs have been deprecated: - The *client* attribute of *txaws.client.base.BaseQuery* - The *date* attribute of *txaws.s3.client.Query* Thanks to everyone who contributed and to Least Authority Enterprises <https://leastauthority.com/> (<https://leastauthority.com/>) for sponsoring my work on this release. Jean-Paul Calderone

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