Anybody has a pointer to an example that implements a HTTP2 Server (in clear text mode) using nghttp2 ?
It depends how you want to implement this.
The easiest way is to use the nghttpd command:
nghttpd --no-tls 80
This is the easiest way of getting a HTTP/2 server up and running to test client implementations. You can also add the -v switch to use verbose mode and log all the frames used.
If you want to write the server in C then the example in the documentation is a HTTPS server, so this would need to be adapted for clear text (h2c).
Finally there is a much easier C++ implementation in the documentation.
Related
I have two applications which I cannot change:
A: provides a URL protected by HTTP basic auth.
B: needs to access this URL but does not support basic auth.
Credentials are available.
How can I make my two applications work together?
I thought a local proxy might be great which injects the authentication. E.g. using socat:
socat TCP4-LISTEN:81,reuseaddr,fork TCP:UrlToA:80,<inject-basic-auth>=user:pass
However, socat does not provide an option like < inject-basic-auth >. Anybody knows any tool that might help? Any other way out?
You must set up a HTTP reverse proxy server that does the authentication for you. No need to hack any software.
Your reverse proxy listens on some socket (e.g. proxy:8080) and forwards requests to your actual application A, inserting the headers.
client_B ----> http://proxy:8080 -----> http://server_A:80
Nginx is lightweight, high performance and easy to set up. And it's easy to find docs online for what you want.
See for example http://wiki.apache.org/couchdb/Nginx_As_a_Reverse_Proxy
This problem seems to be very specific. So you probably won't find a ready-to-use tool.
If you want to do it yourself, your best approach is probably to extend socat:
http://www.dest-unreach.org/socat/download/socat-1.7.2.2.tar.gz
Good luck!
I'm looking into building a service to run in the background that allows clients to connect and send commands, and get data back. I'm planning on writing the service in Ruby (as a gem) but wanted to know what the best method would be to allow clients to connect to the API?
I figured a socket connection would make sense, like you'd connect with Redis or something, but I'm not sure where to start!
Any tips would be much appreciated :)
Yep, you're on the right path. A socket is just a bidirectional communication channel that allows two programs to exchange bytes. If both endpoints are on the same machine, UNIX sockets are the obvious choice; otherwise, you'll need a TCP socket to communicate over the network. The principle is the same in either case.
On top of the socket, you'll have to define your own protocol, or you could use an existing one (such as HTTP) if it applies to your situation.
A random sockets tutorial.
Since you ask for any tips, my advice to you is that building a service container is hard work. Since you don't actually need to, there being lots of awesome service containers already, you should probably use one of those.
I would recommend something behind HTTP, which gives you a whole lot of advantages around existing tooling, message framing, content negotiation, scaling your service, and deployment and upgrade models.
If you want to avoid external dependencies, using something like Webrick or Mongel that is pure Ruby is a fine way to avoid needing to wrap Apache or Nginx around your system.
This also allows you to separate out the concerns in your project: work on building the actual service layer first, handling commands and returning responses. Run that under any web server, and get it going.
Then when you have time, focus separately on how to build the service container to meet your needs: because you know that the underlying service layer works fine, you can focus on only solving the container problems.
If you really do want to build your own container, I strongly recommend you use something higher level than a socket. Tools like 0mq provide framing and other message layer features that you don't get from a socket, and make it much easier to focus on defining the interesting parts of your problem space - the commands - rather than low level details like parsing a wire format and protocol.
I'm using a Ruby/Rails app with Redis running in the background on an EC2 server (Amazon Web Services AWS). This is the ubuntu build I found to be easiest to work with:
Linux version 2.6.32-341-ec2 (buildd#crested) (gcc version 4.4.3 (Ubuntu 4.4.3-4ubuntu5) ) #42-Ubuntu SMP Tue Dec 6 14:56:13 UTC 2011
In my main .rb file that does most of the polling/searching I have this rubygems required, you should definitely check them out:
require 'aws'
require 'redis'
require 'timeout'
require 'json'
Let me know what you are specifically trying to do if that doesn't help you enough. Good luck!
I've built a couple of daemons with EventMachine in the past. It is efficient and powerful, supports TCP, HTTP and everything else. People even write web servers on top of it.
Is it possible to somehow mimic the slower download speeds of my website, as if it is hosted on a web server, but from my localhost?
It's hard to test things like Ajax loading icons when the content loads so quick from your local machine so I think this could help me out a lot?
I was wondering if there was a tool that you could use for this or if you'd need to use javascript to add setTimeout or setInterval code?
If you are using Windows, then download the Fiddler tool Fiddler.
This will setup a HTTP proxy that you can use for testing HTTP headers and view all the HTTP traffic within the PC and browser. You can then use the Rules > Performance > Simulate Modem Speeds option to slow the browser's HTTP connection.
There is also a Fiddler Switch plug-in for Firefox available to toggle the Fiddler proxy.
First of all, please never mangle your code with if ( DEBUG ) workSlowly(); statements. You will get bitten by this practice, and it will hurt.
Second of all, use one of the traffic throttling solutions which have already been posted here. I'm going to add a Java-based solution: Sloppy. It's dead easy to set up and runs everywhere where Java runs.
This question may help you out.
Personally, I add something like this at the top of my library file or whatever file always gets included:
if(DEBUG) {
sleep(2);
}
The above is PHP, but most languages are going to have something similar.
If you're on a *nix platform, you could alter the 'nice' level to basically make your process an afterthought behind most others until you achieve a level of 'lag' that is satisfactory to your needs.
One option is (if You are on linux, but other unix system have similar tools) Traffic shaping (google for 'HTB', 'qdics' and 'tc' command)
Second option will be apache_mod_cband module, this is also probably easer to get going.
You could try Charles. It's cross platform - I use it and it works really well.
http://www.charlesproxy.com/
On windows you can use Proxomitron or you can install fiddler (for ie). Both let you set the download speed.
If you use Fiddler 2, you can install this Add-On: Fiddler - Connection Simulator.
It gives you a nice UI to setup Bandwith and different simulation kinds.
I have a socket app that needs to have support for SOCKS 4 and 5 proxy connections, since my users may be behind firewalls. I am using WPF and C# 3.5 SP1. I see no options in the default Socket class for proxys, do I have to roll my own?
I'd prefer not to use 3rd party libs if possible - how difficult is it to enable proxy support with a standard C# Socket?
It is not terribly hard but you have to read through a couple of RFCs. You need to read the RFC spec on Socks v4, Socks v4a and Socks v5. I wrote a library that will do all the work for you but if you would rather write you own that is cool too. My library was mentioned in the previous post (Starksoft). You can implement the Socks protocol using a standard TcpClient object or a Socket connection. The TcpClient is easier. You simply need to send the commands immediately after connection to your proxy server. Those command will instruct the proxy server what final end point you are interested in connecting to. There is also specs for a UDP Socks connection but it sounds like you won't be needing that.
You can find all the RFCs and generation information on wikipedia. I can't post more because this crazy stackoverflow site limits the number of hyperlinks I am allowed to 1 since I am not a regular user. Very annoying.
http://en.wikipedia.org/wiki/SOCKS
Finally, you can rip off my code if you like since it is under the MIT license and I let you do that kind of thing. :) Take at look at my class Socks4ProxyClient.cs that implements the Socks v4 protocol. The method of most interest to you is named SendCommand() located on line 282. You can find my code at Google Code. Search for Starksoft. Or you can go to my web site directly and I have link to the source code in Google.
Socks5 implementation is a little trickier with more options to specify and a little more chatter to the server but basically very similar to Socks4.
Good luck and you should implement a solution yourself if you want to learn Socks. So, kudos to you!
Benton
You could ask google for some info. One of the first links will lead you to Mentalis.org and their free proxy implementation. They were once well known for their free network and security stuff but the projects seem to not being maintained for a while.
But it might be worth a look anyway.
I know you said that you did not want to use 3rd party librarys if possbile, but I would like to recommend this http://www.starksoft.com/prod_proxy.html.
I want to create a test DNS server in ruby, but could not find anything suitable. I found pnet-dns(http://rubyforge.org/projects/pnet-dns/). This project is incomplete and buggy. Is there any alternative?
A language-agnostic alternative is to use PowerDNS pipe backend. Because it communicates with a name server across a simple pipe, it can be written in any language, including Ruby. (The simple example in the documentation uses Perl but it should be easy to translate.)
RubyDNS is what you're looking for.
Checkout an another approach of DNS server in ruby using celluloid: https://github.com/celluloid/celluloid-dns
The original celluloid-dns is horribly incomplete (v0.0.1). Recently, RubyDNS is being copied into celluloid-dns (I'm doing this as we speak). RubyDNS will be modified to work with the updated celluloid-dns since all core functions will be moved from RubyDNS to celluloid-dns.
If you want something that works right now, use RubyDNS. However, in the future, if you just want the low level APIs, use celluloid-dns.
Have you looked at Dnsruby?
It aims to be fully RFC compliant, although it focuses primarily on the client side. It is, however, possible to write your own server - use Dnsruby::Message#decode to decode incoming packets, and a zone of RRSets holding your test records. You can then encode your packets to send back to the client.