2008年2月19日 星期二

open source supermarket

original


Launchpad is kinda hard to describe. When I’m asked what it is, I normally use three or more of the words “open source free software support project Q&A code registration bugs management listing bazaar planning hosting”. Most people make comparisons to Sourceforge, Savannah, Berlios and Google code hosting, and while those are useful, it’s only a part of the picture. The other part, which is perhaps not as well understood, is that it’s also a public project registration service, similar to Freshmeat. Well, except for a twist.

Launchpad’s source code directory

In addition to providing a project registration service open to the public for free (with probably the best Google juice out there; this has caught some people off-guard before!), Launchpad takes this to a next step, and actually provides a unified interface for interacting with each project registered. The most obvious unified service that you can use today is our code directory, which I want to introduce here.

Now Launchpad provides some key features related to source code for free software projects:

  • Project registration: you can register any free software project on Launchpad (and separately, of course, have it hosted here — if you own it and want to).
  • Bazaar hosting: you can host Bazaar branches for any project, and you can fetch code using the bzr client.
  • Code imports: we allow you to request code imports for any externally-hosted project that uses CVS or Subversion.

There’s a really cool thing that falls out of the combination of code imports, branch mirrors and Bazaar: you can use bzr and Launchpad to fetch any piece of software we have registered code for. And Bazaar even provides a little shortcut that makes it even easier to grab the default branch for any project: bzr branch lp:.

An open source supermarket

The effect is that you can, right now, pull a /lot/ of software in less than 30 keystrokes, without knowing or caring about what its native version-control system is, or where it’s hosted. Want to grab the Python source code? Just do bzr branch lp:python. How about Storm? bzr branch lp:storm. In fact, there are thousands of native Bazaar branches and over one thousand imported branches. Here are just a few examples of major projects you can pull right now:

  • Ruby on Rails:
    bzr branch lp:rails
  • Blender:
    bzr branch lp:blender
  • F-Spot:
    bzr branch lp:f-spot
  • Grub:
    bzr branch lp:grub
  • Twisted:
    bzr branch lp:twisted
  • Bazaar itself:
    bzr branch lp:bzr
  • GCC:
    bzr branch lp:gcc

Couldn’t find a branch listed for the project you want? We can sort this out for you, too. If it’s in CVS or Subversion elsewhere, you can just follow the instructions for setting up an import. If it’s a Bazaar branch, just register it and we’ll hook it up with the project’s mainline series record.

More on project branches

If you visit https://code.launchpad.net/ you’ll notice that it has an abbreviated project cloud, which lists all the projects with branches in Launchpad. The project’s name is rendered in different sizes and intensities according to how active the actual project is; the size of the name in the cloud is defined by the number of branches that the project has, and the intensity of the tag in the cloud is determined by how recent the last commit to any active branch is. And green indicates that there’s a default branch for the project, which means that the bzr branch lp:foo abbreviation works for it. There’s a also a page with the full code cloud.

So each of those projects has active source code branches that you can pull from Launchpad using Bazaar. For instance, to check the source code for Apport, you could click on its entry in the listing and getting there you could inspect the branches available and select one of them for pulling. For instance, if you chose Will Woods’ Fedora support branch you get instructions on how to pull it: bzr branch http://bazaar.launchpad.net/~wwoods/apport/fedora or even just
bzr branch lp:~wwoods/apport/fedora

Imports and today’s deliveries

Import requests are handled in a queue by Launchpad code ninjas; normally this it Michael Hudson’s responsibility but starting today I’ll be helping out too. Of the import requests I handled today, the following succeeded and are ready for grabbing in the great bzr-get-lp-colon fashion:

I’ll keep you posted on new imports as they come online. Meanwhile, go grab some branches and post some comments telling me what you think. If you have any problems or questions about our code hosting service, feel free to ask on the Launchpad code section in answers.launchpad.net.

2008年2月18日 星期一

pjsua as a testing client

原文, original

PJSIP: Command-Line VoIP Client for Linux

January 20, 2008 – 11:10 pm

Some time ago, I was tasked at work with finding an IP telephony client that used the SIP protocol, ran on linux, and did everything from the command line. The goal was to have a program that could be deployed at remote networks to test the quality and performance of VoIP calls between the remote site and our central Asterisk VoIP server. I thought this would be an easy task, but it turned out to be far more difficult to find a client that had all of the necessary features. There are a few command-line SIP clients for linux, and most of them are designed for testing, but paradoxically this means that their feature sets have been limited to simply making a call and playing some sort of wav file or reading text from a file. This was handy for sure, but we needed something that would for all intents and purposes be a full-fledged SIP phone that we could control remotely either with a web script or through SSH.

Yesterday I finally stumbled across a program that fit the bill. More than just a program with a static set of features, PJSIP contains a complete library of functions so that you can build your own programs based on the SIP protocol in practically any language you like. However, it does come with several example applications you can build and use on multiple platforms. The primary application is called pjsua, and contains a fully-featured, menu-based interface for the command line. This program alone did everything we needed and more.

Pjsua is incredibly easy to use. Run without any options, it presents you with a nice menu-interface where you can add accounts, add and view the status of other SIP users, make calls, transfer calls, put calls on hold, conference calls, and even pipe in audio from wav files. If you’re in a hurry, you can make a call with the following short and simple command:

pjsua sip:<user>@<domain>

Or if you know the IP address of the other user, you can do the following:

pjsua sip:<ip address>

Chances are you’ll want to have a registered account on a server running something like Asterisk. You can use command-line options to specify the account details every time, or you can put the command-line options into a config file and have pjsua load that instead using the following syntax:

pjsua –config-file=<config file>

One of the neatest features of pjsua is the ability to run it in “daemon” mode, officially called auto-answer. In this mode, pjsua sits idling, waiting for an incoming call. When it detects an incoming call, pjsua answers and can do several different things. Here is an example command:

pjsua –null-audio –play-file=data3.wav –auto-play –rec-file=call001.wav –auto-rec –auto-answer=200 –config-file=pj-config

Broken down, this command tells pjsua to run, register itself with the central server with the details provided in “pj-config”, to listen for incoming calls and automatically answer with code 200 (for those of you familiar with HTTP status codes, SIP status codes are remarkably similar), to loop data3.wav after answering the call, and to record any audio on the line (except the wav file being piped in).

Why on earth would this be useful? Say, for instance, I have a business client using my VoIP service at the other end of the state. He calls me to complain that call quality has been atrocious for the past few days. There are a few things I can do. I can take up a bunch of his time having him troubleshoot with me on the phone, I can drive all the way across the state and troubleshoot the issue myself, or I can use the web server we’ve also installed on his network to make my own test calls without ever leaving my office or tying up the client’s time or phone line. I can simply place a call to the test number and listen to the looped recording for evidence of audio quality issues. This only tells me half the story however, as often times with VoIP sessions only one side of the conversation is affected. This is where the recording comes in, as I can now download it from the remote server and analyze it for problems. This saves both time and money, and provides an easy yet effective way to track down problems.

Pjsua is a fully featured SIP client, so if you have speakers and a microphone on your system, you can use this just like you would any other soft-phone. However, given that there are several other soft-phones for linux with a nice GUI interface, one of them may be a better choice if your goal is simply to make and receive calls from your computer. But if you need something to run in a windowless environment, or you’re like me and need something lightweight to help troubleshoot VoIP issues, you can download Pjsua and the entire PJSIP library from http://www.pjsip.org.