i-am.ws |
Alpha for PNG with NetPBM
As a co-developer of pnmtopng / pngtopnm it's already a long time my plan to update those two NetPBM programs for the PAM format, allowing for proper alpha channel support. On sourceforge you can find a pngtopam program — not sure how full featured it is — but there is currently no pamtopng, which is IMHO the more important of the two.
Two weeks ago I was myself in desperate need for a PAM to PNG converter, and I didn't have the time to do some proper development, therefore decided to do a quick & dirty one. Luckily I wrote 10+ years ago two PngMinus tools, which was targeting the same type of converters, but without the need for the NetPBM libraries.
Long story short, I wrote a "pam2png" utility, which is not as feature rich as a pamtopng program would be, but it does the job. Its main purpose is to convert 4-channel "RGB_ALPHA" pam images to png, but it does the conversion of 2-channel "GRAY_ALPHA" as well. However, the latter wasn't extensively tested.
To be honest, I stopped testing and debugging when the program was good enough for the images I needed to convert to PNG. And I will not spend too much more time on it, because the real goal is a proper pamtopng implementation. But if you find bugs, send me the fixes and I will incorporate them. Don't waste your time on adding functionality, because this is just a temporary job.
Finally, if you don't know how to create those PAM images with R+G+B+A channels, check out the pamstack command. This tool allows you to combine a regular RGB ppm image with an alpha channel image packaged in a pgm file. The README file in the tar-ball shows how to do it.
@ 2011 Dec 18 12:33 AM, entry [ alpha_for_png_with_netpbm ] was posted in [ linux ]
jQuery Mobile on Android
I developed an app for BlackBerry PlayBook that is using the jQuery Mobile toolkit to create the user interface. Now jQM is a portable framework that can run on many platforms, ranging from your regular Chrome, FireFox or Safari browser, to mobile devices like iPhone or Android.
Searching for how to deploy jQuery Mobile on Android, most examples are written as a WebApp. The code is loaded on a web-server and you point your Android browser to it to start the app. But what I wanted was everything packaged in an .apk file that can be installed from the Android AppMarket. To achieve this, you have to create a small Java wrapper around your html and JavaScript code. In this tutorial I will be using Eclipse on CentOS as my development platform.
- First step is to create in Eclipse a new project: "File > New > Android Project" and give it a name (let's say "IceCream", I copied the jQM code from a blog by Matt Doyle), select the target and enter the package name, like "ws.iam.icecream". Keep Create Activity checked.
- Next we'll be adding a WebKit WebView to onCreate():
package ws.iam.icecream;
import android.app.Activity;
import android.os.Bundle;
import android.view.Window;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
public class IceCreamActivity extends Activity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.main);
WebView webView = (WebView) findViewById(R.id.webview);
WebSettings webSettings = webView.getSettings();
webSettings.setJavaScriptEnabled(true);
webView.setWebViewClient(new WebViewClient());
webView.loadUrl("file:///android_asset/index.html");
return;
}
}
- This WebView will replace the LinearLayout in res > layout > main.xml.
<WebView xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/webview"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:scrollbars="none" />
- While we're at it, we should update the AndroidManifest.xml file. Just after the <use-sdk> parameter, add the following line:
<uses-permission android:name="android.permission.INTERNET"></uses-permission>
- You probably want to replace the default res > drawable > icon.png files (in three resolutions) with your own.
- Now we get to the core of this tutorial. Which is how to wrap the html, css and javascript of jQuery Mobile. Those files get all placed in the "assets" folder of the Eclipse project. And our Java Activity is attaching to that with the "webView.loadUrl()" call that we saw above. So, right click "assets", then "New > File" and give it the name "index.html". Right click the file and do "Open With > Text Editor" and now copy-paste our Ice Cream Order html code into it.
- Typically the jQuery Mobile javascript libs get loaded from the web. But I prefer to make it part of the package. Again right click "assets" and "New > Folder" and call it "js". Now, outside of Eclipse, copy your "jquery-1.5.2.min.js" and "jquery.mobile-1.0a4.1.min.js" into this "Workspace/IceCream/assets/js" folder. Similarly create a folder "assets/css" and copy "jquery.mobile-1.0a4.1.min.css" into it.
- At the top of your index.html file, include the following lines:
<link rel="stylesheet" href="css/jquery.mobile-1.0a4.1.min.css" />
<script src="js/jquery-1.5.2.min.js"></script>
<script src="js/jquery.mobile-1.0a4.1.min.js"></script>
and if you have your own javascript and stylesheets, add those as well:
<link rel="stylesheet" href="css/icecream.css" />
<script type="text/javascript" src="js/icecream.js"></script>
Finally, within Eclipse, right click these files and do a "Refresh".
And now you're all set to run your new app. Probably first just in the emulator. Give it a shot and you should see something like this.
Although this is a working app now, with the java code doing nothing more than being a wrapper, I like to add some native Android functionality. And that is a menu to Reload the app and to Exit it. To do that we've to add two more methods: "onCreateOptionsMenu()" and "onOptionsItemSelected()". Check it out in the complete source code for the Activity.
That all being done, you've to package up the whole thing, sign it and upload it to the Android market. I use Eclipse for this:
- select your IceCream project
- then "File > Export"
- expand the "Android" option and select "Export Android Application", click "Next"
- and "Next" again
- enter the details of your key-store (I assume you have one), click "Next"
- select "Create new key", click "Next"
- give your key the alias name "icecream", enter and confirm a password, give it a validity of 25 years, enter your name and country code and click "Next"
- enter folder and filename "IceCream.apk"
- and finally you can click "Finish".
The resulting packaged and signed application can be uploaded to the Android market, or copied to your Android device using a USB key.
@ 2011 Nov 20 01:58 PM, entry [ jquery_mobile_on_android ] was posted in [ desktop ]
CentOS 6 boot from USB
Installing CentOS 6 on a laptop without CD/DVD seemed to be easiest by using a Live-USB stick. However, on the net there were warnings that version 6 behaves different from CentOS 5. And indeed, it took me too a couple of attempts before I was successful. I downloaded the LiveCD ISO for CD, not DVD, because with 700 MB, it would fit on the 1 GB USB key I had lying around.
After a little research, I opted for this livecd-iso-to-disk script (or get it from GIT), which promises to do it all automagically. My first problem was that my CentOS 5 system didn't have 'udevadm', which I solved by changing in the script "udevadm info" into "udevinfo" and swapping "udevadm settle" for "udevsettle". After that, the USB key would build, until the stick had to be made bootable. Long story short, the isolinux / extlinux in CentOS 5 is too old. I could have downloaded a more current tarball and built it, but I was too scared that that would break something else.
My solution was to move the whole project to another system running a more current OS, in this case Fedora 15. After installing extlinux with a "yum install syslinux-extlinux", not only my udevadm issues were solved, but it also had a more recent isolinux, version 4. One tip: if you copy everything to the USB key and then at the end something breaks, like my extlinux, you can use the option "--skipcopy" to save quite a bit of time. Finally, I used an ext3 filesystem on my stick and it is a good idea to start each new attempt with a "mkfs.ext3 /dev/sd@#".
After booting from the USB stick, the next steps were of course an "Install to Hard Drive", then a "yum update", followed by using the GUI to install a whole slew of RPM packages.
@ 2011 Oct 15 06:03 PM, entry [ centos_6_boot_from_usb ] was posted in [ linux ]
Slimp3 server with Voyage
With two SLIMP3 players in the bottom drawer (if I remember correctly, each around sixty bucks on eBay), it got time to make some better use of them. Now I've always had a SlimpServer / SqueezeBox running on the same box that's doing my MythTV, but I needed a setup independant from that. A small server, running Linux and Slimp, making no noise and preferably being cheap. That was the goal.
I started my research for Single Board Computers (SBC) again, checking out the latest status on Fit-PC and SheevaPlug. But then I found this little gem: the "alix3d3" from PC Engines. A Swiss company that makes SBC's in a form factor smaller than micro ITX. The board I got is 10x16 cm, powered by an AMD Geode processor and includes VGA, network port, 2x USB, RS232. And if you add a mini-PCI you can even do wireless.
For my Slimp3 server, I added a 512 MB CompactFlash to boot from and a 16 GB USB stick for the music library. I could order all of that for less than 200 bucks including a pretty cool aluminum enclosure. The total size is smaller than an external 3.5" harddisk. Now the thing I'm still most amaized about is that that little Kingston thumbnail on the right is storing 300 CDs. I need quite a couple of bookshelves to store the physical CDs these MP3's came from.
Now the fun part was of course the software install. Did a bit of research and with this reduced hardware, a full blown Fedora or Ubuntu is not the way to go ..... but who needs X-Windows on a media server. The answer is a distro called Voyage. Based on Debian, but targetted at this type of SBC controllers. By itself it fits in roughly 100 MB, but when you include the squeezebox software and then the various dependant packages, it just fits in the 1/2 GB I had at hand.
Here follows my little HOWTO on installing it. The first step is to install Voyage on your CompactFlash, while it is still hooked up to your dekstop:
# fdisk -l /dev/sda Disk /dev/sda: 512 MB, 512483328 bytes 16 heads, 63 sectors/track, 993 cylinders Units = cylinders of 1008 * 512 = 516096 bytes Device Boot Start End Blocks Id System /dev/sda1 * 1 993 500440+ 83 Linux # mkfs.ext2 /dev/sda1 # tune2fs -c 0 /dev/sda1 # bunzip2 -k ./Voyage-0.7.5.tar.bz2 # tar xvf ./Voyage-0.7.5.tar # cd ./Voyage-0.7.5 # more ./README # more ./README.live-cd # # ./usr/local/sbin/voyage.update # What would you like to do? [Create new Voyage Linux disk] What would you like to do? [Select Target Profile] Please select Voyage profile: [ALIX] What would you like to do? [Select Target Disk] Which device accesses the target disk [/dev/sda]? Which partition should I use on /dev/sda for the Voyage system [1]? Where can I mount the target disk [/mnt/cf]? What would you like to do? [Select Target Bootstrap Loader] Which loader do you want (grub or lilo) [grub]? Which partition is used for bootstrap [1]? What would you like to do? [Configure Target Console] Select terminal type: [Console] What would you like to do? [Partition and Create Filesystem] What shall I do with your Flash Media? [Use Flash Media as-is] What would you like to do? [Copy Distribution to Target] OK to continue (y/n)? y What would you like to do? [Exit]
Next step is to move the CF card to your ALIX computer and boot that one. Then you've to install the SlimpServer / SqueezeBox packages. One of the problems is that the name of these packages has changed a couple of times, while Logitech took over Slimp. Based on this WiKi page, here is what finally worded for me:
# cat /etc/apt/sources.list deb http://debian.slimdevices.com stable main deb http://ftp.hk.debian.org/debian/ squeeze main contrib non-free deb http://security.debian.org/ squeeze/updates main contrib non-free # apt-get remove --purge slimserver # apt-get remove --purge squeezecenter # apt-get remove --purge squeezeboxserver # apt-get update # apt-get install squeezeboxserver
With that, your Slimp3 should work, but only when it is in "remountrw" mode. That's because SqueezeBox writes a cache to /var/lib, which is on Voyage a 'read-only' protected filesystem. To run your whole system, including the squeezebox software, in "remountro" mode, the trick is to modify your /etc/init.d/squeezeboxserver so that it copies the contents of /var/lib/squeezeboxserver to a new directory you create as /tmp/lib/squeezeboxserver. Next you've to change couple of environment variables in the squeezeboxserver setup to point to that directory instead of using /var/lib.
Enjoy the music!! The audio quality will be noticably better than what your typical computer can produce.
@ 2011 Oct 09 12:08 AM, entry [ slimp3_server_with_voyage ] was posted in [ linux ]
UCSand - You See Sand
UCSand is an Android application I recently developed to monitor a Cisco UCS blade system. The UCS Manager running on the Fabric Interconnects is based on an API using XML over HTTP. It is relatively easy to write shell or Perl scripts to collect data from the UCS system. Or to control it, like booting blades or turning the blue locator LED on or off.
A while back someone else developed a client GUI for the iPhone/iPad. With the Cius being released, a similar app for the Android platform is needed. Being a proud owner of an original "Google Developer Phone", it was time to get to work. Android code has to be developed in Java, so "talking XML over HTTP" isn't that difficult. It all comes down to old style socket programming.
I opted for keeping the app relatively simple. It's mainly a monitoring tool that allows you to check on the status of your system when you're remote. It shows the configuration of your blades and you can go through the alarms and warnings for the various components in your system. On purpose I didn't include more complex actions like (dis)associating a service profile. Those things are better done from the fully featured UCS Manager.
You can get the UCSand app from the Android Market, or just search the market for Cisco UCS. The current version will show more or less information about the blades depending on the size of the screen. On a phone, you've to click on a blade to see details, on a tablet you see some details and the status of the blade next to the image.
Finally, if you want to see the app in full action, check out the Mobility in the Datacenter blog of one of our customers at the City of Melrose.
@ 2011 Jul 24 10:37 AM, entry [ ucsand_you_see_sand ] was posted in [ datacenter ]
PnmBlend Disappearing Act
Recently I was working on an automated tool to create images of 19" racks with their content. I got a nice picture of the new Cisco R42610 rack, but with the doors off, it still showed the hinges. No big deal, but it made the picture a little ugly.
I wanted to let those hinges disappear and had to be able to make it a repeatable thing. Therefore I didn't want to do it with PhotoShop, but preferred to script it using NetPbm. Now, NetPbm didn't have the right tool for the job, so it was time to write my own. Wasn't the first time, ten years ago I wrote together with Alex the pnmtopng/pngtopnm converters and more recently I contributed "pnmmercator", a cartography application.
The result of my current effort is "pnmblend", a little utility that will take the top and bottom row of an image (or the left and right column) and replace everything in between with a fading (or gradient) from one to the other.
On the left you see the rack with the hinges still there. The next picture zooms in and the third shows the piece we've cut out to work on with "pnmblend". After that you see the output of my new utility and the last image is the result of putting it back in the original image using "pnmpaste".
This code isn't yet ready to be included in the official NetPbm package. For that I've to convert it from a 'pnm' to a 'pam' utility. Secondly, the current code isn't based on the NetPbm libraries, but is doing it all in itself. Which could in certain cases even be an advantage.
@ 2011 Jan 29 09:14 PM, entry [ pnmblend_disappearing_act ] was posted in [ linux ]
PQ PartitionMagic 983
On my Windows XP laptop, the C: drive partition had become too small. So, I freed up some space just after it to grow it to double its size. There are many ways to do that, but my favorite tool is PowerQuest's PartitionMagic. However it failed with an "Error 983 - Too many errors found, process halted.".
Googling that message proved that I wasn't the only one. The solutions ranged from doing a "Disk Cleanup" to running "chkdsk /f". An interesting suggestion was to remove old Restore Points on Microsoft's Support site. I tried all of those, but to no avail. And then there are the many "PC Health" or "Download 983 Repair Tool" ads at the top of the Google page. Everything else failing I opted for one of those, paid thirty bucks and let it do its magic. An hour later I tried Partition Magic again, but error 983 was still there.
While doing all that, I noticed an option in PQ Magic to convert the partition from NTFS to FAT32. That sounded intrusive enough :) that it could fix this 983 error. I went ahead and not surprisingly also that one failed, but now with an "Error 1681 - Data is compressed or sparse.". Researching this on the Symantec support site, suggested to "Turn off System Restore".
You find that option by right clicking "My Computer" (if your Desktop doesn't have a shortcut to My Computer, do this in Windows Explorer) and then click "Properties". Select the "System Restore" tab and enable "Turn off System Restore on all drives". Having done that, I went back to Partition Magic to try the resize operation again (yes, I put my convert to FAT32 on the back burner). Suddenly all went well and two minutes later I had doubled the size of my C: drive.
@ 2010 Nov 21 08:43 AM, entry [ pq_partitionmagic_error_983 ] was posted in [ desktop ]
Apache mod_substitute
When building my new Apache Roller system, I had quite a few challenges with the i-am.ws domain, served from a web-server in the DMZ and Roller on a Tomcat server in the backend. The mod_proxy Apache module takes care of most of it, but hardcoded URLs in the html code need to be translated as well from the internal IP to the external domain name.
A month went by and I found the solution in stumbling on the "mod_substitute" and "mod_sed" modules. With those, the proxy can fix on the fly the hard-coded URLs generated by Roller. In this scenario, substitute "http://192.168.1.23:8080/roller/" for "http://www.i-am.ws/" and you're all set. The only thing to be aware of is that you must be running a pretty recent version of Apache (2.2.7 for "mod_substitute" and even 2.3 for "mod_sed").
Now that sounds like a done deal, but it took me couple of weekends to figure out a nasty snag with "mod_substitute" and the like. I thought it was caused by mod_proxy and mod_substitute clashing with each other. So I thought I was clever :-) and moved mod_substitute to the back-end. I installed another Apache on a different port (8642) that would do a local proxy to Tomcat (on 8080). It didn't fix the problem, but by doing I discovered that when I retrieved the web-page with "wget" (one of my favorite hacking tools) instead of Firefox, string substitution worked fine. Now my suspision moved to issues with HTTP 1.0 vs. 1.1. Again, that wasn't the case.
Getting desperate, I decided to write my own proxy server. Grabbing some old bits and pieces of code still lying around :-), that wasn't too tough. At first, things went fine and then the same thing happened again. But with my own code – not running in the background – I had a much better handle on debugging. Checking the HTTP headers of the request, I suddenly noticed that Firefox sends to the server an "Accept-Encoding: gzip, deflate" http header record (BTW, same with IE). And yes, the server replied with all html code nicely compressed. Which suddenly explained why all this time mod-substitute couldn't do anything with it. It also explained why wget, not sending that header, was working fine.
For now, I'm sticking with my home-grown proxy, but the proper solution is I guess to use mod_rewrite to get rid of those compression HTTP headers. And then mod_substitute can do what it's supposed to do.
@ 2010 Apr 25 11:33 AM, entry [ apache_mod_substitute ] was posted in [ linux ]
Witte Fietsen Plan
Hopefully your Dutch is sufficient to understand the title :). In flower-power Holland – 45 years ago on my birthday – the Provo movement started an initiative in Amsterdam to provide everybody with free bicycles. Just grab one, and leave it when you're at your destination. To distinguish these bikes and prevent them from being stolen, they were painted white. The whole thing didn't work, at least not at the time in that form.
I had to think of that last week, when I came out of the office to grab my blue bike to go back home. Mmmm, not such a good plan. My bike wasn't dark blue anymore, but bright white. A sudden late afternoon snowstorm had turned my trusted piece of commute transportation into a solid piece of ice. Oh well, just a night in the garage fixed that problem.
@ 2010 Apr 17 11:44 AM, entry [ witte_fietsen_plan ] was posted in [ general ]
Alsa Microphone
While trying to install Skype on RedHat Linux, I discovered that although I thought that sound was running fine on my CentOS 5.3 box, in reality it was only doing half the job. Playing music was fine, but capturing sound from a microphone had never properly worked. Both "/usr/bin/system-config-soundcard" and "gnome-sound-properties" didn't show anything obvious (Autodetect for the three playback options and ALSA for the sound capture), but clicking the last test button didn't result in hearing the sound of the microphone on my headset.
Another way to test this is with:
# arecord -d 5 -f cd -t wav foobar.wav # aplay foobar.wav
and in my case, I didn't hear anything while doing the playback.
It took lots of googling, but here is what you need to do. First of all, you can have the problem that your system has audio ports both on the front and the back of the system. For speakers or headsets you just plug it in anywhere and it works. Typically the front plug will disable what's plugged into the back. But for mics those two ports are not the same.
# /usr/bin/amixer ... Simple mixer control 'Mic Select',0 Capabilities: enum Items: 'Mic1' 'Mic2' Item0: 'Mic1' ...
On my system Mic1 was the input on the back of my PC, so I had to switch to Mic2 to use my headset that is plugged into the front. To change, use "/usr/bin/alsamixer", which opens a clumsy GUI, then click 'right' to get to "Mic Select" and use 'up'/'down' to change the Mic. Press 'Esc' to quit.
But that's not enough. Let's go back to our 'amixer' output.
# /usr/bin/amixer ... Simple mixer control 'Mic',0 Capabilities: pvolume pvolume-joined pswitch pswitch-joined cswitch cswitch-exclusive Capture exclusive group: 0 Playback channels: Mono Capture channels: Front Left - Front Right Limits: Playback 0 - 31 Mono: Playback 22 [71%] [-1.50dB] [on] Front Left: Capture [on] Front Right: Capture [on] Simple mixer control 'Mic Boost (+20dB)',0 Capabilities: pswitch pswitch-joined Playback channels: Mono Mono: Playback [on] ...
When I was running this the first time, it showed "Front Left/Right: Capture [off]". That's no good!! But how to change, because my alsamixer didn't show this as an option that can be changed. The following command will do the job:
# amixer sset Mic Capture cap
After that, maybe you should go back to alsamixer and switch the "Mic Boost" option on. You do that by moving right with the cursor and then press the 'M' key. Another option further right is "Mono Out", which can be 'Mic' or 'Mix'. I'm not 100% sure what it should be, I settled for 'Mix'.
Finally, while you're doing all this, you should keep your 'Volume Control' window open. For example, playing test sounds with the soundcard config tool will mute the microphone. And in other cases the level gets automagically :-) set back to zero. You better watch out.
This was for me just the prologue for installing Skype. The best way to do that successfully I found on this Hackery blog. Here is the summary.
# the skype binaries are 32-bit, so if you're running a 64-bit system, you # need to make sure you have various 32-bit libraries installed in parallel yum install glib2.i386 qt4.i386 zlib.i386 alsa-lib.i386 libX11.i386 \ libXv.i386 libXScrnSaver.i386 # installing to /opt cd /tmp wget http://www.skype.com/go/getskype-linux-beta-static cd /opt tar jxvf /tmp/skype_static-2.1.0.47.tar.bz2 ln -s skype_static-2.1.0.47 skype # setup some symlinks (the first is required for sounds to work) ln -s /opt/skype /usr/share/skype ln -s /opt/skype/skype /usr/bin/skype
Other good tips can be found on this CentOS HowTo webpage.
@ 2010 Apr 07 02:13 PM, entry [ alsa_microphone ] was posted in [ linux ]
Yum Local Install
Yesterday I was trying to configure a music player on an old laptop running Fedora 8. It required some additional packages for mp3, but when I tried to do a "yum install gstreamer-plugins-ugly" it appeared that this old stuff didn't exist anymore in any of the on-line repositories.
Luckily, pbone.net came to the rescue. I downloaded the RPM package, then tried to install, but there were a whole slew of dependencies that needed to be resolved first. Damn .... normally it means that one-by-one you've to search the net to figure out which RPM includes that specific shared library and then the result is often even more unresolved dependencies.
Don't know why, but I checked the man-page for yum and found that there is a "localinstall" command. What it does is that you use yum to install an already downloaded rpm package, but it will then use the on-line repositories to resolve the dependencies. Kind of "best of both worlds" approach.
# yum localinstall gstreamer-plugins-ugly-0.10.8-1.fc8.i386.rpm
Of course you have to hope that not too many of the other packages you need has the same issue of having disappeared from the repositories. But luck was on my side yesterday. Couple of minutes later I had my Muine Music Player running and the MP3 music was flowing out of the speakers.
@ 2010 Mar 21 11:04 AM, entry [ yum_local_install ] was posted in [ linux ]
I-am.WS
All blog entries below this one were written as part of my "blogs.sun.com" weblog. But that blog comes to an end, because around Xmas 2009 I left Oracle/Sun to join Cisco. Similar role, Datacenter Architect for Cisco's new UCS platform, later more about that. As a consequence, I can't add to my old blog anymore and I presume that anyway blogs.sun.com will soon be rolled into one of Oracles blogging sites.
For me, time to figure out another venue. I decided to install my own apache-roller (the same blogging software Sun was using), on a box in my basement running Apache and Tomcat. One of the reasons for going this route was that, couple of years ago, I managed to acquire the domain name "i-am.ws". "WS" being my initials, that seemed pretty appropriate as the new name for a blogging site. The sat image in the header is West Samoa, where these domains originate from.
This not being a "what did we have for dinner" blog, but rather more "food for techies", I have to share here a few of my experiences moving my blog from Sun's IT into my basement. The laptop I'm using, is a "goldie-oldie" PII with 256 MB of RAM. That dates it pretty well and therefore it is running RedHat EL3, nothing fancier, but hey, it's doing the job. Therefore it also has an older MySQL version (3.23.58), the same for glibc, etc.
At first I tried to install latest-greatest Roller 4, which became a disaster, all kinds of dependency conflicts. And that makes sense, on top of a 5 year OS you better build a five year old software stack. However, it can be a little scramble to find all the older sw packages. In this case I "dropped down" to Roller 3.1, picked Java 1.5 SE JDK and Tomcat 5.5. Which combination seems to work pretty well together.
The bigger challenge was that my i-am.ws domain points to another webserver on my LAN, which functions as a proxy to my CMS-Made-Simple, my Myth-Web box and now this Roller instance on Tomcat. Typically I fix the fact that different domains are being served by the same webserver, by creating an Apache HTTPD "Virtual Host" with the following parameters.
ServerName ecliptic.net ServerAlias www.ecliptic.net ServerAdmin webmaster@ecliptic.net DocumentRoot /var/www/html/ecliptic.net
But in this situation, that's not enough. We've to proxy to the tomcat server on the other box. Therefore we need to add a couple of 'ProxyPass' and 'ProxyPassReverse' parameters. The following isn't perfect, but I wanted to have "/" (the root of my domain) point to "/roller/wwwillem" on the Tomcat engine. Which makes things a little trickier.
ServerName i-am.ws ServerAlias www.i-am.ws ServerAdmin webmaster@i-am.ws ProxyPass /roller/roller-ui/ http://192.168.1.23:8080/roller/roller-ui/ ProxyPassReverse /roller/roller-ui/ http://192.168.1.23:8080/roller/roller-ui/ ProxyPass /roller/theme/ http://192.168.1.23:8080/roller/theme/ ProxyPassReverse /roller/theme/ http://192.168.1.23:8080/roller/theme/ ProxyPass /roller/wwwillem/ http://192.168.1.23:8080/roller/wwwillem/ ProxyPassReverse /roller/wwwillem/ http://192.168.1.23:8080/roller/wwwillem/ ProxyPass /wwwillem/ http://192.168.1.23:80/roller/wwwillem/ ProxyPassReverse /wwwillem/ http://192.168.1.23:80/roller/wwwillem/ ProxyPass / http://www.i-am.ws/ ProxyPassReverse / http://192.168.1.23:8080/ CustomLog /var/log/httpd/i-am-ws_access.log common ErrorLog /var/log/httpd/i-am-ws_error.log
Finally, the biggest problem is that Roller generates in many spots HTML with the base URL hard baked into the code. So, if the browser finds the Tomcat application with "i-am.ws" or even "i-am.ws/roller/wwwillem" the html page will be created with hard-coded links to http://http://192.168.1.23:8080/roller/wwwillem/. These should have been relative links of course and probably Roller 4.0 fixed a lot of that, but after googling this for a long time, it seems that there are still many issues around this. I searched for an Apache module that would scrape the html returned to make the necessary corrections, but such a thing doesn't seem to exist.
Anyway, for me the most important thing is to have my WebLog up and running again. In some future I will probably upgrade the whole thing to some newer platform (likely CentOS 6 when that's out, or Fedora 12), but for now, this is good enough. As usual, it was a good learning experience.
@ 2010 Mar 15 11:41 PM, entry [ i_am_ws ] was posted in [ general ]
Oracle Sun Better Together
In some bottom drawer I found this old marketing credit card CD from Oracle and Sun. It's probably from the same era as the VOS (Veritas, Oracle, Sun) initiative.
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@ 2009 Oct 11 12:26 PM, entry [ better_together_cd ] was posted in [ datacenter ]
VirtualBox USB Ports
Running CentOS as my host OS and using VirtualBox to run "everything else", it didn't take long before I was running into USB problems. In my case I had a Windows 2000 guest on a CentOS 5 host (same for RedHat EL) and I wanted to use ActiveSync to connect to my WM5 Windows Mobile device.
I'm diverting for a sec, but this is the big reason why I like VirtualBox so much. I do software development for the Windows Mobile platform (http://www.locatea.net/) which requires a lot of software installation for Visual Studio and then even more for the various Windows Mobile SDKs. It is quite a job to get it all installed correctly. Previously that whole install could (and would) easily be screwed up because some completely unrelated application would mess up the registry, forcing you to reinstall the server and start from scratch.
Now, by virtualizing my desktop, I have an instance that I solely use for Windows Mobile software development. If I need Microsoft Office I do it in another Windows guest. And if I want to tryout a new software package that I don't really trust, I simply clone my base image and install it in there. If the app doesn't work out or behaves badly, I can simply blow the whole image.
So, where many people think that desktop virtualization is just great for running different types of OSes on a single host, IMHO it is even more important because it allows you to create multiple environments, that have very dissimilar functionality, but can have the same platform requirements. Of course I also use it to run OpenSolaris on my Mac. :-)
Back to USB in Windows guests. Out of the box it doesn't work, at least not on my platform. A little googling provides a lot of recommendations to add an entry to /etc/fstab (none /proc/bus/usb usbfs devgid=501,devmode=0664 0 0). It seems that for Ubuntu this fixes the problem, but not for RedHat / CentOS. It took me a lot of searching, but finally I found in an obscure corner of some forum a solution. You have to modify your /etc/rc.d/rc/sysinit file.
if [ ! -d /proc/bus/usb ]; then
modprobe usbcore >/dev/null 2>&1 && mount -n -t usbfs \
/proc/bus/usb /proc/bus/usb -o devgid=501,devmode=664
else
mount -n -t usbfs /proc/bus/usb /proc/bus/usb -o devgid=501,devmode=664
fi
This piece is mainly already there, but you need to add the "-o" parameters. In here "501" is the GID you have specified in your /etc/group for the vboxusers group.
After having done this, the Windows guest recognizes USB sticks, external hard drives and nicely connects to my mobile phone.
@ 2009 May 23 11:16 AM, entry [ virtualbox_usb_ports ] was posted in [ virtual ]
Bizarre ftp Behaviour
After spending couple of hours editing a webpage, I lost all that effort when copying the file to my webserver. And of course before the automatic backup had been made. :-(
As always, there is a lesson to be learned.
Try this yourself:
$ ftp webserver ftp> prompt Interactive mode off. ftp> mput * local: img_2.gif remote: img_2.gif 227 Entering Passive Mode (192,168,32,72,126,33) 150 Opening BINARY mode data connection for img_2.gif. 226 Transfer complete. 12980 bytes sent in 4.2e-05 seconds (3e+05 Kbytes/s) local: img_3.jpg remote: img_3.jpg 227 Entering Passive Mode (192,168,32,72,126,33) 150 Opening BINARY mode data connection for img_3.jpg. 226 Transfer complete. 28488 bytes sent in 0.017 seconds (1.6e+03 Kbytes/s) local: webpage.html remote: webpage.html 227 Entering Passive Mode (192,168,32,72,164,239) 150 Opening BINARY mode data connection for webpage.html. 226 Transfer complete. 12498 bytes sent in 4.5e-05 seconds (2.7e+05 Kbytes/s) ftp> ls * 227 Entering Passive Mode (192,168,32,72,219,226) 150 Opening ASCII mode data connection for /bin/ls. total 268 -rw-r--r-- 1 wwwillem wwwillem 12980 May 20 09:08 img_2.gif -rw-r--r-- 1 wwwillem wwwillem 28488 May 20 09:08 img_3.jpg -rw-r--r-- 1 wwwillem wwwillem 12498 May 20 09:08 webpage.html 226 Transfer complete. ftp> ls -l 227 Entering Passive Mode (192,168,32,72,207,63) 150 Opening ASCII mode data connection for /bin/ls. total 268 -rw-r--r-- 1 wwwillem wwwillem 12980 May 20 09:08 img_2.gif -rw-r--r-- 1 wwwillem wwwillem 28488 May 20 09:08 img_3.jpg -rw-r--r-- 1 wwwillem wwwillem 12498 May 20 09:08 webpage.html 226 Transfer complete.
So far all has gone well. Notice the file-size of webpage.html, 12 kB.
Now comes the problem:
ftp> ls -l *html 227 Entering Passive Mode (192,168,32,72,142,146) 150 Opening ASCII mode data connection for /bin/ls. 226 Transfer complete. ftp> quit 221-Thank you for using the FTP service on webserver. 221 Goodbye. $ ls -l webpage.html total 62 -rw-r--r-- 1 willem willem 209 May 20 09:07 webpage.html
Notice how the file has shrunk from 12 kB to only couple of hundred bytes? Let's have a look at the (new) content.
$ cat webpage.html total 123 -rw-r--r-- 1 willem willem 12980 May 20 09:01 img_2.gif -rw-r--r-- 1 willem willem 28488 May 20 09:01 img_3.jpg -rw-r--r-- 1 willem willem 209 May 20 09:07 webpage.html
What happened here? The 'ls *' ftp command was ok, same for 'ls -l'. However when we did 'ls -l *html', the result of the 'ls -l' command was written to the local html file, in this case webpage.html. That's definitely not what I would have expected to happen. Very weird behaviour!!
Finally, the client was ftp on CentOS 5 and the server was an ancient RedHat 6.2 server. And no, 6.2 is not the successor of EL5. :-)
@ 2009 May 20 08:42 AM, entry [ bizarre_ftp_behaviour ] was posted in [ linux ]
VirtualBox on Solaris
To implement a SunRay demo with a Windows Terminal Server back-end, normally we use two separate servers. But now, with virtualization all around us, why not put those two components on a single box. Of course, there are many ways to skin the cat. I decided to take the X4100 that I had in the lab, put Solaris 10u4 on it, then install Sun Ray Server Software (SRSS) and finally install VirtualBox with a Windows 2003 Enterprise Edition guest server for the backend.
However, this entry is not about Sun Ray or Windows, but about VirtualBox. When selecting the correct download, it was a bit unclear if there were separate versions for Open Solaris versus normal Solaris, or that it was all "one and the same". To jump couple of steps ahead, there is only one version, but it is clear that the developers of VirtualBox are doing their work with OpenSolaris and then expect it to work with regular Solaris as well.
Well, as I discovered, and with me many others, that doesn't always work out. The pkgadd is straight forward and without problems. At the end you will have VirtualBox in your path and you're ready to fire it up. But then I got the following error
bash-3.00# VirtualBox ld.so.1: VirtualBox: fatal: libGL.so: open failed: No such file or directory
Things like this have happened before, and my usual solution is "let's Google". In this case that was the wrong thing to do, :) because I got soooo many wrong suggestions. In some forum I read that something is wrong with the service "svc:/application/opengl/ogl-select:default" or that you have to install the package "sunwcslr". In my case, none of this was true.
I'm sure that most of the problem is related to the difference between 32 and 64 bit systems. Not only the CPU, but also the OS and therefore the libraries must be matching. With my X4100, I was running a 64 bit AMD Opteron. I had installed Solaris running in 64 bit mode and I hadn't made the mistake of downloading the 32 bit version of VirtualBox.
Here's some commands you can use to verify your own configuration regarding these issues.
bash-3.00# uname -a SunOS java3 5.10 Generic_120012-14 i86pc i386 i86pc bash-3.00# ls VirtualBox* VirtualBox-1.6.2-SunOS-amd64-r31466.pkg VirtualBox-1.6.2-SunOS_amd64.tar.gz VirtualBoxKern-1.6.2-SunOS-r31466.pkg bash-3.00# isainfo -k amd64 bash-3.00# which VirtualBox /usr/bin/VirtualBox
This looks good, 64 bits all where it matters. But why are things still going wrong when you start VirtualBox. No matter what all the other forum messages are saying, in my case it was in the end simply a matter of not finding the 64 bit version of libGL.so. I tried many other things first, but what solved it was setting LD_LIBRARY_PATH to include "/usr/X11/lib/mesa/64".
bash-3.00# VirtualBox ld.so.1: VirtualBox: fatal: libGL.so: open failed: No such file or directory Killed bash-3.00# echo $LD_LIBRARY_PATH bash-3.00# export LD_LIBRARY_PATH=/lib:/usr/lib/64:/usr/X11/lib/mesa/64 bash-3.00# echo $LD_LIBRARY_PATH /lib:/usr/lib/64:/usr/X11/lib/mesa/64 bash-3.00# VirtualBox ^C bash-3.00#
Which shows what went wrong and how it can be fixed.
@ 2008 Jul 26 08:56 AM, entry [ virtualbox_on_solaris ] was posted in [ solaris ]
Silence and Pavlov
Today I got my SunRay@Home. For those of you not working at Sun, that's a Sun Ray attached to your home network that directly VPNs (from the firmware) into SWAN, the corporate network. It allows for hot-desking from your cubicle to your study and vice versa. Pretty cool stuff.
Reason I wanted to have one at home was mainly eco driven. When I do things like software development I need a full blown desktop. But in the morning, between alarm clock and shower, I'm only drinking my first coffee and checking my email. Why should I fire-up the big desktop to only use a browser and an email client. And that was my background to sign up for the SunRay@Home program.
I got my unit today, installation was a jiffy. Everything fine, Sun Ray on my left display, PC on the right LCD. Around 10 PM I decided to shutdown the desktop PC. And then came the big surprise: For the first time in many, many years (probably twenty) I was using again a computer with zero background noise. No, not just the "nearly silent" that laptops give you, but simply absolute nothing!! It was lovely, but at the same time even weird, I guess a kind of reverse Pavlov effect (in this case I got the food but there was no bell). It appears that browsing the web and the noise of fans are by now in our minds tightly intertwined.
I do use a Sun Ray in the office, but of course modern offices can't be called noiseless. I have to go back 15 years, when I used my trusty VT220 and a modem into the office, for the last time I worked with a computer that didn't make noise. And then 20-25 years back when my desktop system consisted of a 6502 based BBC-micro computer. That one also without fans, but you still had the rattling sound of the floppy drives. :-) For the rest, it seems I've always had fans around me when I was doing my computer stuff.
So, this SunRay@Home is a keeper. I can hear the wall clock ticking again. The only thing I need to do is to replace the green power LED of my SR2 with a blue or a white one. That green is too ugly with the brushed aluminum.
@ 2008 Jul 18 10:30 PM, entry [ silence_and_pavlov ] was posted in [ desktop ]
ILOM and DHCP
It happens too often that at customer sites there are issues around the IP address for the Service Processor. The proper way to handle this is IMHO simple: For each server, add an entry to the DHCP server, where based on the MAC address of the SP, a known IP address will be assigned. This way, everything is controlled by a centralized DHCP configuration but still each server gets a "semi static" IP address.
Unfortunately, in many situations customers can not implement this, or they simply don't want to. The "can not" is most likely not based on technical arguments, but has mainly to do with organizational and responsibility issues.
Your second option is to set the Service Processor IP address from the BIOS. Which works fine, but sometimes it can be hard to find a monitor and keyboard in a Data Center. Or nobody is willing to give you a free static IP address. Third option is to let the SP do a DHCP request and monitor the logfiles on the DHCP server to see what address was handed out. Which won't work if the person who needs to use the SP has no access to the DHCP server.
The end result is that you can easily end up in a Catch 22. In the old days of V20/40z servers, we had those tiny LCD screens and you could even set the IP address using a few buttons on the front of the server. But the newer generation doesn't have those features anymore.
Last week, I was again confronted with this problem (on a corporate network, where I had zero privileges) and I solved it in a different way. What I did was write a little script that tries to ping every IP address in the subnet, or better in the range that is available to the DHCP server. Kind of "poor man's port scanner". The script (let's call it "pingscan.sh") is pretty primitive and looks like this.
#!/bin/sh for i in 13 14 15 16 17 18 19 20 21 22 23 24; do for j in 0 1 2 3 4 5 6 7 8 9; do ping -n -t 1 192.168.1.$i$j 1 done done
This will scan addresses from 192.168.1.130 to 192.168.1.249, adjust the values for your network. The "-t 1" and the "1" at the end (this is Solaris ping) will take care that with one second gaps, each address in the subnet will be tried. For Linux use "-c 1" and no trailing "1". So, the script will take a few minutes to complete, depending on the range.
Fire up your server and let the SP do a DHCP request. Then run "pingscan.sh > before". And here comes the trick! Disconnect the network cable to the SP and run "pingscan.sh > after". A simple diff of the two files will show which IP address was given to the SP.
# diff before after 57c57 < 192.168.1.186 is alive --- > no answer from 192.168.1.186
The script could be made much fancier, but this one only uses /bin/sh and can be typed in a couple of minutes. On a large and busy network it could happen that you will get multiple candidates. And of course this is not a preferred solution, because it isn't guaranteed that a week later the DHCP server won't give a different IP address. But this trick can help when you find yourself in a nasty corner. At least, it did that for me.
@ 2008 Jul 14 06:53 PM, entry [ ilom_and_dhcp ] was posted in [ network ]
Solaris Security
It's already dark when I leave the hotel, dragging my carry-on behind me. I can turn left, to the pub where the rest of the troops is probably already behind their second beer, but I decide to make a little detour to the right. I walk to the front of the 18-wheeler to see if Dan, the driver of our Project Blackbox rig, is still around. I find him, with big gloves on, between the power generator and the water chiller. He is working hard to make the Blackbox transport ready again. We shake hands to say goodbye.
I met Dan for the first time in Calgary a month or so ago, great guy, not only the driver of our Blackbox demo roadshow unit, but also the one who took the most fabulous pictures of the box in between the high-rise of Calgary's downtown core. Today we are in Vancouver. Different bussiness drivers, but the same crowd that gets inspired by Project Blackbox and sees how it can open new avenues for datacenter expension, consolidation and "going green".
After my goodbye to Dan, who's now off to Mexico City, I join my colleagues and then it's off to the airport. For those of you who are "frequent flying" as well, you know the drill. Empty your pockets, get all your keys and stuff into the grey plastic bin, your laptop in the second bin, your coat in the third, etc.
But now it comes....
One of the security folks, I would guess around 60 years old, sees my Sun badge in the bin next to my coins, my keys and phone. He asks me out of the blue, "but is Solaris free" .... and it is clear he means it in the "free as in beer" sense. It catches me a little off guard, but my reply is "you can just download it, no problem". His counter "yeah, but do I get source code and am I then able to change it?" I try to assure him with "of course, that is what open source is all about". Next question: "but do I need assembler code to do this?" (now you understand why he was at least 50+ :-). I hope I was correct, but my answer was "no problem, it's all C code, you will be fine".
And this all happened within 20 seconds, five times the speed of an elevator pitch, while at the same time I was emptying my backpack to get my laptop into the gray plastic bin, etc. Time was flying way too fast!! I would have loved to talk with this guy about what project he was working on. He was a really interesting person. As a day job checking our bags for stupid things like bottles of shampoo, but in the end really interested in how he could modify and improve Solaris.
That's special !!
@ 2007 Nov 21 12:20 AM, entry [ solaris_security ] was posted in [ solaris ]
Half Baked User Friendly
I guess since Windows 98 or so, it's the default in Explorer not to show you file extensions. Probably Microsoft hoped they could beat Apple in user-friendliness and thought that the icon would be good enough to show you the filetype. And maybe that would have been OK, if it had been implemented correctly (as a set of meta-data) like on my good-old NeXT.
It can't be that I'm the only one who completes every Windows install by: a) go to 'Folder Options' -> 'View' and unselect the 'Hide File Extensions', then b) take care that Explorer and the MS-DOS box are not hidden deep down in the 'Accessories', but are icons on the Desktop, part of the toolbar, and in the main of the Start menu. I guess I've done that now a hundred times. And it annoys me that with each and every newer Windows version, this stupid UI design is still there.
Tonight, this whole thing went a step further, and even more bizar. On a latest-greatest Windows Mobile phone, an application failed and wrote its results to a logfile (let's call it abc-xyz) in the root directory. I tried to open the file by double clicking it, but I got a pop-up that I had to open the application first and then open the file. OK, so I started 'Mobile Word', clicked 'Menu', then 'File' and found a wide range of options (like New, Save, etc.) but not 'Open'. Duh ....
In the options screen I discovered that there is a feature to select what types of files Word Mobile will show me, which even includes 'All Known FileTypes'. Mmmm, that sounded good, but still no luck. Finally I discovered that my file was in reality called abc-xyz.log, but the extension was, as explained above, not shown and secondly a .log file is appearently not a "known filetype" for Windows Mobile. When downsizing Explorer to the Mobile platform, it seems they had to drop the option 'Show All Files'. As if there is not enough memory for all the other bloatware.
But OK, I got closer to a solution. Let's simply rename the file to 'abc-xyz.txt', or even '.doc' and then all will be fine. Ehhh, not so!! Word still couldn't see the file. That was when I discovered that the rename in Explorer had rebaptized my file into 'abc-xyz.txt.log'. Which makes sense when you keep the .log part hidden, but it is absolute BS if the result is that you can't open a simple log file anymore. All in the sake of user friendliness.
You start to wonder how much usability testing has been done on a feature like this. And even more what audience the Windows developers had invited for these sessions. It's my guess that these were not a group of power-users and that the software developers were thinking that if the UI was good enough for them, it would be more than good enough for more sophisticated people. WRONG!!!
Long story short, in the end the only way to open my logfile in any application was to copy it from the phone to my desktop and use some editor to open the file and see its five lines of content.
@ 2007 Jun 28 08:33 PM, entry [ half_baked_user_friendly ] was posted in [ desktop ]