Archive for the ‘Fedora’ Category

Why automatically push to rawhide?

Wednesday, December 8th, 2010

One of the things that bothers me about Fedora development is that things automatically end up anywhere after being built. I’m a big believer in having to do something to put software in the hands of users, even if they are running a development distribution, and even if they should “be able to fix whatever breaks”. Today, if you build something in rawhide, it’ll land on user machines tomorrow (in the default case). This applies especially if you do a “known good” build and then do “just one more” before the early morning hours when the mirrors get updated with today’s version.

In my opinion, rawhide isn’t a playpen. It’s supposed to be a place where things bake, but it should not be the place where random crap is shoved that might (or might not) randomly break things because it hasn’t even been tested on a local machine somewhere first. I think packages should always at least pass a boot/login test (or whatever appropriately similar activity) on a local system before they are made available in rawhide, and there should be some minimal activity involved to indicate that a package is intended for pushing (not just a build that wasn’t done as a scratch or that needs to be tested, etc.). It doesn’t have to require any proventester, any specific QE, any whatever, but it should require that the packager type something that indicates they built this package intending for it to be used by a lot of rawhide users. Again, rawhide is for fun, but it’s not a playpen.


[rant] How do I do that?

Friday, December 3rd, 2010

So, I was sitting in a hotel room earlier looking at their (simple) instructions for folks to configure their windows laptops. The instructions say exactly what menu options to select, where to find them, etc. Those menu items are always in the same place, with the same names, and have the same functionality across all updates.

I’ve been thinking a lot recently about how Linux is increasingly defining inter-operability based on the random decisions of engineers hacking on projects, and not on industry standards. Engineers who run the latest and greatest software at all times are absolutely the last people who should ever get to make such decisions because they will never notice when someone with a three-year-old distro runs into trouble. Conversely, the groaning starts the moment something is more than ten minutes old. In the real world (a place where people don’t run rawhide, and might be on F-12 by now…maybe – trust me, I talk to computer people who use Linux but aren’t hard core Linux kernel/distro hackers every day), people don’t upgrade every day, don’t run the latest software, and compatible standards matter.

Not only should we not re-invent the wheel as often as does happen (for no gain other than to make it impossible to have a simple “Linux way” to do something – sure your whizz-bang solution boots faster and looks prettier but I never asked you for it and what I had was probably good enough), but we should actually use industry bodies to produce standards, or at least make a bigger effort to standardize. I want, in the future to walk into a hotel room and see “this is how you do this in Linux” instructions, not instructions for Fedora, Ubuntu, blah blah. Because in the latter case nobody is going to care enough to do it and Linux will continue to be a mere afterthought.

Two steps to fix this problem:

  • 1). Every project should have architects who set direction and whose opinion counts as gospel on decisions that will impact user experience. They can veto the silly wheel re-invention exercises. People who don’t like that can go hack on Linux From Scratch in their basement.
  • 2). Every project should work with independent industry bodies to standardize the moment some new feature comes along. So that there is one “Linux way” to do it, and not ten different but similar ways to do the same thing.

That’s my two cents (sense) on a Friday. If those things happened, users would be the better for it. You may now arrogantly tell me how wrong I am and how much better the world would be if none of that happened.


Automated recording with Asterisk

Saturday, November 20th, 2010

So I decided to write a recipe for recording conference calls with Asterisk. Let’s say you have a dialin bridge number and a bridge passcode and you want your server to connect at certain times, announce that you are going to record (and periodically remind that you are doing so), and then do so. Optionally, you might ask the moderator to confirm this by pressing a key. You might spend many hours figuring this out, which is why I’m going to show you how.

First, you need some canned audio files. I use the following in my example (which I record using a studio microphone and then convert into sln files with the sox command: sox jcm-beep.wav -t raw -r 8000 -s -c 1 jcm-beep.sln):

  • jcm-beep – a tone indicating recording is ongoing
  • jcm-record_question – ask the moderator if they want to record
  • jcm-record_confirm – confirm that you will begin recording
  • jcm-record_cancel – announce that you have not made a recording
  • jcm-record_reminder – reminder that you are recording
  • jcm-record_limit – announce that recording time has been exceeded
  • jcm-record_timeout – announce that the limit for a response was exceeded

With those recordings in place (/usr/share/asterisk/sounds for example), add the following subroutine “context” to your /etc/asterisk/extensions.conf:


exten => h,1,Set(GOSUB_RESULT=ABORT)
exten => h,2,Return()

exten => s,1,Answer()
exten => s,2,Wait(2)
exten => s,3,Set(STARTSTAMP=${EPOCH})
exten => s,4,Set(TIMEOUTSECS=30)                                                ; 30 second timeout
exten => s,5,SendDTMF(00${CONFCALLPWD},200)
exten => s,6,Wait(15)
exten => s,7,Set(WAITSTART=${EPOCH})
exten => s,8,GotoIf($[${ASKTORECORD} == 1]?100)
exten => s,9,Goto(9,1)

exten => s,100,Set(WAITTIME=$[${EPOCH}-${WAITSTART}])
exten => s,101,BackGround(jcm-record_question)
exten => s,102,WaitExten(5)
exten => s,103,GotoIf($[${WAITTIME} <= ${TIMEOUTSECS}]?100)
exten => s,104,PlayBack(jcm-record_timeout)
exten => s,105,Set(GOSUB_RESULT=ABORT)
exten => s,106,Return()

exten => 6,1,Answer()
exten => 6,2,PlayBack(nothing-recorded)
exten => 6,3,PlayBack(goodbye)
exten => 6,4,Set(GOSUB_RESULT=ABORT)
exten => 6,5,Return()

exten => 9,1,Answer()
exten => 9,2,Set(MAXRECORDSECS=4000)                                            ; just over 1 hour
exten => 9,3,GotoIf($["${CONFCALLNAME}" != ""]?100)
exten => 9,4,Set(CONFCALLNAME=conf-call-${STRFTIME(,,%Y%m%d-%H%M%S)})
exten => 9,5,Goto(100)

exten => 9,100,Set(CALLREMINDBEEPINT=180) ; time in secs between beeps
; every 3 minutes
exten => 9,101,Set(CALLREMINDMSGMULT=5) ; number of beeps before message        ; every 15 minutes
exten => 9,102,Set(CALLREMINDBEEPCNT=0) ; current number of beeps
exten => 9,103,Set(CALLFILENAME=${CONFCALLNAME}-${STRFTIME(,,%Y%m%d-%H%M%S)})
exten => 9,104,Monitor(wav,${CALLFILENAME},m)
exten => 9,105,Set(RECORDSTART=${EPOCH})
exten => 9,106,PlayBack(jcm-beep)
exten => 9,107,PlayBack(jcm-record_reminder)
exten => 9,108,Goto(200)

exten => 9,200,Set(RECORDTIME=$[${EPOCH}-${RECORDSTART}])
exten => 9,201,Wait(${CALLREMINDBEEPINT})
exten => 9,202,PlayBack(jcm-beep)
exten => 9,204,GotoIf($[${CALLREMINDBEEPCNT} < ${CALLREMINDMSGMULT}]?210)
exten => 9,205,PlayBack(jcm-record_reminder)
exten => 9,206,Set(CALLREMINDBEEPCNT=0)
exten => 9,207,Goto(210)
exten => 9,210,GotoIf($[${RECORDTIME} <= ${MAXRECORDSECS}]?200)
exten => 9,211,PlayBack(jcm-record_limit)
exten => 9,212,Set(GOSUB_RESULT=ABORT)
exten => 9,213,Return()

Notice that there are still a few hard-coded variables in there, and that the bridge password is always prefixed with a “00″ since these first digits are generally lost in my case). There are two good ways to use this. The first is to add a test extension on your local server, which you can do using the Dial command with an option including U(conf-record). Since there’s a bug in the version of Asterisk I am running (now fixed upstream), I also append S(1) to force the call to hangup on successful connection. A more useful way to use this is with a call file. Create something like the following file (I prefix variables with double underscores to ensure they are always inherited with call properties):

Channel:	SIP_OR_IAX_TRUNK_HERE/19783038021
WaitTime:	60
Context:	conf-record
Extension:	s
Priority:	1
SetVar:		__CONFCALLNAME=fedora-talk-testcall
SetVar:		__CONFCALLPWD=2014

This is configured to connect to Fedora Talk conference room 2014 (general purpose room), announce itself, ask if it is ok to record, and then begin the recording (some conferenece systems don’t pass through DTMF, so you might need to explicitly disable ASKTORECORD in those cases – especially if you have permission anyway). If you copy this file into your /var/spool/asterisk/outgoing directory with correct ownership (for example, using vixie cron) then Asterisk will detect it and begin the recording. Those on the call will hear (for example): “beep…just a reminder that this call is being recorded”. Then every 3 minutes they will hear a (gentle!) sound, and every 15 they will hear an audible reminder that the call is being recorded like at the beginning. After recording, the call will be placed in the usual monitor directory. Have fun!


Android and Linux

Thursday, November 18th, 2010

So I went to the BLU – Boston Linux User Group – meeting tonight. I hadn’t been in a long time, but the talk was by a guy (Greg Milette) writing actual Android apps that have sold in the app. Market, so I thought it might be fun. It certainly was interesting to hear about practical app. development, not just listening to the same folks bitching again about how Google might or might not have modified the kernel and other bits to provide their desired user experience. Greg demonstrated writing an app, building, and testing, it, and I certainly got the feeling that my intention to have a small app that updates my GPS location on a server periodically (in order to allow me to have my Asterisk and IRC servers automatically route calls/set me away, etc.) would not be too tricky to pull off in a reasonable amount of time. I upgraded my Nexus One to CyanogenMod 6.0 recently and think I’ll find some time to play sometime.

Linux User Groups used to be very hard core affairs, where you’d have some pretty meaty stuff. These days, I generally avoid them because they’re catering to a different audience – not a wrong audience, but just not my cup of coffee. These days it’s often about pretty GUI stuff I don’t care about, and very “high level” discussion. And everyone has a laptop or netbook open and is reading email rather than paying attention. Tonight wasn’t too bad, although there was a guy in front who had discovered a “cow” application that could be run on the command line and would display a picture of a cow with a speech bubble full of whatever text he passed to it. That guy sat there for about 20 minutes (at least) playing with this, typing in various text, laughing to himself, and reminding me why I stopped going to LUGs at least 5 years ago (or maybe that was when he was on YouTube and found a video of dancing cows to complete the theme for his evening). Of course, all of this was on a laptop running Ubuntu. As was everyone else. Nobody there was running anything other than Ubuntu. Not a Fedora in sight. I have opinions on pragmatism that I believe explain precisely why nobody was running Fedora, but nobody is interested in hearing those anyway.


More fun with Asterisk (video)

Tuesday, November 9th, 2010

So tonight I added some more database directories to my Asterisk server. For example, it now knows the numbers of most of my colleagues and will give them a special message (including internal contact information, etc.), has several databases for unwanted callers, specific greetings for others, and additional logic to handle various other fun. Here’s a video:


Some more fun with Asterisk

Monday, November 8th, 2010

So I moved to the US a while back. When I did that, I retained a mobile number in the UK that many people already had in their address books, and for those occasions when I might visit. For the longest time, I had it setup on permanent divert to a SIP trunk in the UK, that connected to an Asterisk server in Texas and then a SIP trunk in the US, out to my US cellphone. Callers never even realized that they were actually speaking to me on my US cellphone when calling my “UK” one. A nice hack for cheap roaming (I wrote an article on this some years ago now), and a great way to say “screw you” (but slightly more strongly) to the phone carriers who still overcharge for roaming. But we can do better.

Recently, I learned that A&A have started a UK mobile service that uses SIP extensions exclusively, basically giving you a SIP trunk into a cellphone handset. No more call forwarding. The phone is the SIP extension and can be configured just like any other (when will US carriers wake up? ever?). I’m hoping to get one the moment they can port my existing number (they’re still working on number porting), so that I can just have a UK SIP extension for when I am in the country. In the interim, I got another SIP trunk for playing around and forwarded my old mobile number to that one, with a customized message that will still forward to me after a delay. The message informs the caller that I am in a different timezone and since it now knows that calls to that number can only have come from the mobile, it can do some other nice things too. Ultimately, the call still winds up hitting my US cellphone, unless it’s from sales or marketing folks.

Anyway. While I was at it, I used what is commonly known as “ex-girlfriend logic” (someone once had to solve the “problem” of handling calls from their ex, so it became known as this, but it’s used for many different purposes!) to add special rules for all kinds of numbers. For example, I recorded special messages for organizations that routinely call to harass me and added rules to catch their calls through their caller ID (fakeable, but most organizations don’t do this today). These messages say things such as: “Organization A, your number has been recognized as belonging to Organization A. I have previously requested that you stop calling me with sales or marketing calls. If your call is not for sales or marketing reasons, please leave a message. If you are calling to sell me something, please also leave a message, explaining that you have heard this, have added me to a do not call list, and won’t be calling me again”. The messages vary, but the gist is clear. Then the call goes to voicemail and my phone never even rings.

A similar process happens when callers to my UK trunk need to be informed that I am not “Iceland Express”, the airline which has a number very similar to my own. Calls still reach me, but after a message explaining that I am not the airline they might be trying to reach. In due course, I would like to have the system record numbers that have already heard this message and don’t need to hear it again (if they aren’t exchange numbers – need a way to detect that also, maybe in the signalling data somewhere?). Conversely, the phone system recognizes my family and girlfriend and saves them from listening to my greeting every time, making their calls reach me a few seconds faster than some others, though with a funny message for fun.

At this point, I have a growing number of Cisco 7940 series IP phones around my apartment, as well as soft phones, and a number of trunks and mobiles that are all hooked together. When you call me, your call has all of the rich features of Asterisk. For example, you will (and have for years now) hear music on hold while the system rings all of my phones in unison, have a menu with various options, etc. I can easily record calls, transfer them between phones or countries, and I have speed dials configured for popular numbers that I need to reach (some of which will also setup pre-agreed recording, if it’s a conference). Oh, and I’ve been hooked into Fedora VoIP for a while now too, so that just gets handled like any other incoming call. My phone has a special dialplan prefix for Fedora, the same as how it also recognizes UK numbers and automatically dials the international bit and routes cheaply through the UK trunk without any need to do anything special.

What I would like to do next is to have a DNS service (perhaps RFC2916 compliant) that I could use my Asterisk server against in order to do anti-spam filtering of the form that I do already with spam-assassin. I would love to know if such a service exists, and if not, why not? I would love to be able to add wildcard rules to my Asterisk server to match on specific names of organizations, whose exact number might vary (but can be looked up in the database to find their name), in order that they will always get the special handling that I have deemed appropriate for them. With such a service, you could also easily and automatically exclude all known telemarketing numbers with a single command. Anyone point me to such a setup?


Playing with EDID and rawhide

Monday, November 8th, 2010

Photo: Modesetting problems with 2.6.37-rc1 and the i915 driver.

So there was an innocuous patch to i915 EDID code (in the intel_lvds setup code) that introduced cacheing of the EDID data, but in the process stopped reading panel data correctly on boot, which would result in all kinds of weird modesetting problems on these Intel parts. Like my ASUS Eee PC 1015PEM, where the screen was moved down an inch or so such that there was blank space at the top and the bottom inch of the screen was “missing”. You can see a photo above (and my upstream posting had a video). A lot of bisecting over the weekend tracked this down, and I very much enjoyed working briefly with the excellent Chris Wilson to test fixes. It should be that 2.6.37-rc1+the posted fix on LKML works well on various random panels again, such as this netbook.

Meanwhile, I’ve been actually using rawhide on the netbook, in the spirit of dogfooding (which is why I bought that netbook – to have a controlled and safe environment for playing with unstable software). It’s been tough though. A small list of the many issues currently includes: Lots of the conversion from GNOME2 to GNOME3 is hitting me. I’m unable to run rhythmbox (hasn’t worked in ages), the volume control applet won’t start, and ABRT frequently generates traces that are unusable (so I removed ABRT). Also, the screensaver won’t ever exit (without killing gnome-screensaver on the command line), and recently my sound stopped working completely. I fixed the latter by completely removing pulseaudio from the system (and filing several bugs – including one to have gnome-bluetooth not depend on PA). But it’s not all bad. The desktop mostly works, the browser has been fine, and evolution is able to send email now that the annoying “crash on sending mail” bug has gone away for me.

Nonetheless, at this point, my “exclude” yum configuration grows larger daily. The system is, at this point, usable for poking and playing around with experimental kernels, but I simply could not use rawhide on a daily basis as my main desktop environment, without a lot of deep meditative breathing. In my own personal opinion (of which all of this is personal opinion), the lack of any stability in rawhide is counter-productive. Sure, yea, it means you can shove anything you like in the distribution. But it also means you can shove anything you like into the distribution. I know there is a updates testing staging area, but part of me pines for the old days of Debian testing, where you knew you’d get cutting edge stuff, but you’d also know it had baked for a week or two first. I personally would like a direct equivalent in the rawhide space, which isn’t the same as the branching we have now. I like the branching, and I think it’s a far better system, but I’d also like a two-stage rawhide. And a pony, let’s not forget about the pony before people think I don’t realize how not trivial this stuff can be to implement.

UPDATE: I tried a combination of pulseaudio and gnome-shell. This results in sound, but the mixer in gnome-shell doesn’t control the PA output (just slides up and down with no effect), sound settings crashes, contol center won’t start, etc. I suspect I will go back to GNOME2 again tomorrow with PA removed again.

UPDATE2: Yup. Removed PA again and went back to GNOME2.