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.
Related
I currently have a primitive RPC setup relying on JSON transferred over secured sockets, but I would like to switch to gRPC. Unfortunately I also need access to AF_UNIX on windows (Which Microsoft recently started supporting, but gRPC has not implemented).
Since I have an existing working connection (managed with a different library), my preference would be to just use that in conjunction with GRPC to send/receive commands in place of my JSON parsing, but I am struggling to identify the best way to do that.
I have seen Plugging custom transport into gRPC but this question differs in the following ways (As well as my hope for a more recent answer)
I am wanting to avoid making changes to the core of gRPC. I'd prefer to extend it if possible from within my library, but the answer here implies adding a new transport to gRPC.If I did need to do this at the transport level, is there a mechanism to register it with gRPC after the core has been built?
I am unsure if I need to define this as a full custom transport, since I do already have an existing connection established and ready. I have seen some things that imply I could simply extend Channel, but I might be wrong.
I need to be able to support Windows, or at least modern versions of it (Which means that the from_fd options gRPC provides are not available since they are currently only implemented for POSIX)
Has anyone solved similar problems with gRPC?
I may have figured out my own answer. I seem to have been overly focused on gRPC, when the service definition component of Protobuf is not dependent on that.
How can i write my own RPC Implementation for Protocol Buffers utilizing ZeroMQ is very similar to my use case, with https://developers.google.com/protocol-buffers/docs/proto#services seeming to resolve my issue (And this also explains why I seem to have been mixing up the different kinds of "Channels" involved
I welcome any improvements/suggestions, and hope that maybe this can be found in future searches by people that had the same confusion.
I need to do something relatively simple, and I don't really want to install a MOM like RabittMQ etc.
There are several programs that "register" with a central
"service" server through TCP. The only function of the server is to
call back all the registered clients when they all in turn say
"DONE". So it is a kind of "join" (edit: Barrier) for distributed client processes.
When all clients say "DONE" (they can be done at totally different times), the central server messages
them all saying "ALL-COMPLETE". The clients "block" until asynchronously called back.
So this is a kind of distributed asynchronous Observer Pattern. The server has to keep track of where the clients are somehow. It is ok for the client to pass its IP address to the server etc. It is constructable with things like Boost::Signal, BOOST::Asio, BOOST::Dataflow etc, but I don't want to reinvent the wheel if something simple already exists. I got very close with ZeroMQ, but non of their patterns support this use-case very well, AFAIK.
Is there a very simple system that does this? Notice that the server can be written in any language. I just need C++ bindings for the clients.
After much searching, I used this library
https://github.com/actor-framework
It turns out that doing this with this framework is relatively straightforward. The only real "impediment" to using it is that the library seems to have gotten an API transition recently and the documentation .pdf file has not completely caught up with the source. No biggie since the example programs and the source (.hpp) files get you over this hump. However, they need to bring the docs in sync with the source. In addition, IMO they need to provide more interesting examples on how to use c++ Actors for extreme performance. For my case it is not needed, but the idea of actors (shared nothing) in this use-case is one of the reasons people use it instead shared memory communication when using threads.
Also, getting used to the syntax that the library enforces (get used to lambdas!) if one is not used to state of the art c++11 programs it can be a bit of a mind-twister at first. Then, the triviality of remembering all the clients that registered with the server was the only other caveat.
STRONGLY RECOMMENDED.
I can't find this on Google (so maybe it doesn't exist), but I basically'd like to install something on a web server such that I can run a site on Scheme, PHP is starting to annoy me, I want to get rid off it, what I want is:
Run Scheme sources towards UTF-8 output (duh)
Support for SXML, SXLT et cetera, I plan to compose the damned thing in SXML and -> to normal representation on at the end.
Ability to read other files from the server, write them, set permissions et cetera
Also some things to for instance determine the filesize of files, height of images, mime-types and all that mumbo-jumbo
(optionally) connect to a database, but for what I want to do storing the entire database in S-expressions itself is feasible enough
I don't need any fancy libraries and other things that come with it like CMS'es and what-not, except the support for SXML but I'm sure I can just find a lib for that anyway that I can load.
Spark-Scheme has a full web server. If you don't need that, it also has a FastCGI interface so that you can serve Scheme scripts from a web servers like Apache, Lighttpd etc. Spark-Scheme also seem to meet your requirements for database support, UTF-8, file handling and SXML. See the Spark-Scheme Programming Guide (pdf) for more information.
mod_lisp and FastCGI are the only two Apache modules I'm aware of that might work at this time. mod_lisp provides Scheme support because it's architecture is similar to FastCGI, where CGI like parameters are sent over a socket to a second process which remains running as the Scheme backend to the web server. Basically you use one or the other to send CGI like parameters across a socket to a running Scheme backend.
You can find some information about these solutions here. There was another FastCGI like effort called SCGI which demoed a simple SCGI receiver in Scheme called gambit. That code is probably not maintained anymore, but the scheme receiver might be useful.
Back in the Apache 2.0 days, there were more projects playing with scheme and clisp bindings. I don't believe that mod_scheme ever released anything, but if they did, odds are it is not compatible with the modern releases of Apache.
Did you come across Fermion (http://vijaymathew.wordpress.com/2009/08/19/fermion-the-scheme-web-server/)?
If you're looking for a lispy language to develop web applications in, I'd recommend looking into Clojure. Clojure is a lisp variant that's fairly close to scheme; here is a list of some of the differences.
Clojure runs on the Java virtual machine and integrates well with Java libraries, and there's a great webapp framework available called Compojure.
Check out Chicken Scheme's Eggs Unlimited. I think what you want is a combination of the sxml- packages coupled with the fastcgi package.
PLT Scheme has a web application server here: http://docs.plt-scheme.org/web-server/index.html
I'm trying to create a raw socket using Ruby.
The problem is, there isn't anything called "raw socket" there and, on the other hand, the Socket class itself is not fully documented.
Does anybody have some code samples for that kind of socket in Ruby, or maybe some kind of a documentation for that?
By the way, I already know how to work with TCPSocket and TCPServer classes, and what I need is particularly a raw socket.
Google brings up the following result: http://www.ruby-forum.com/topic/90408
Short version:
require 'socket'
rsock = Socket.open(Socket::PF_INET, Socket::SOCK_RAW, Socket::IPPROTO_RAW)
rsock.send(string, flags)
rsock.recv(1024)
More documentation on the various Socket classes: http://www.rubycentral.com/pickaxe/lib_network.html
(The whole raw sockets thing is rather nasty on unices since it usually requires root access. I did not test this code. You may need to construct the whole packet yourself if you're not using IPSocket)
Have a look at the racket gem (https://rubygems.org/gems/racket). It seems to be a bit outdated since the last version was released in 2009 but its also used in the metasploit framework.
Have a look at PacketFu. It is very well maintained and used by the Metasploit Project.
I'm looking to start a MUD client application, which connects to a MUD hosted on a telnet server. The only thing important to me is that it runs painlessly and efficiently across any OS. Aside from that requirement, I'm not really sold on any language.
So I'm looking for a freely available telnet client library on which I can base my application, so I don't have to deal with the details of the protocol too much.
I would always consider Twisted for this kind of thing (Python).
The beauty is that if you later decide to swap it out to SSH or anything more secure than telnet, you can with little pain.
Twisted, twisted, twisted!
To use telnet, see package twisted.conch.telnet. It's got some spartan API docs, but the real information on using it comes from searching on Google Code Search, such as this nugget from grailmud - a MUD server.
For all of my MUD programming, I just created my own routines from the ground up using the RFCs.
In case you'd like to avoid some of my pain, I wrapped it up into a fairly simple C# class that handles Telnet properly. In case you'd like to peruse it, you can view it here.
This code has been copy/pasted and run on Windows and on Linux (through Mono) on a handful of separate projects and works pretty good.
There is a telnet interface in CPAN if you like Perl. It's pretty minimal, but it should get the job done.
[edit]
libcurl is also supposed to be able to do telnet, although I couldn't find any examples of it.
pmc ( http://sourceforge.net/projects/perlmudclient/ ) was an attempt to do exactly this. I've spent some of the last week going through it; it uses an older modified version of Net::Telnet to do its connectivity work.
My problem is that Net::Telnet seems to have a blocking interface when a partial line is sent by the server, i.e. a line not terminated by a newline. It has two features that support this (waitfor and its prompt mechanism), because almost all telnet servers have prompts that are not newline-terminated.
MUDs often have "prompts" that are non-standard and vary through the course of the game; the MUD I admin on has a "Your choice: " prompt as its login [it's not just for usernames], and many game features present alternative prompts. So I suspect you'll need to bear this in mind when you go looking for a cross-platform Telnet library!
If you like C, I heartily recommend libtelnet. It will maintain an internal state that does all the IAC sequence parsing for you, and handles option negotiation using the Q method.