As work on webinterface for YaST is in progress we must learn new technologies suitable for web development. WebYast will be written in ruby and ruby on rails framework. Also because WebYast is new interface it could contain AJAX features for better user comfort. Today I found that ajax support in RoR is on good level and with documentation it takes few minutes to create first example which show current used memory on server. It is not connected anyhow to YaST because I want to focus on AJAX.
And here is a code. It update page every fifth second (but not refresh only update div, on bigger page it is really significant):
/views/home/index.html.erb:
<%= javascript_include_tag :defaults %>
<h1>Hello world!</h1>
<%= periodically_call_remote(:url => { :action => 'get_averages' }, :update => 'avg',:frequency => '5') %>
<div id="avg">
Memory usage is X MB </div>
controllers/home_controller.rb:
class HomeController < ApplicationController
   def index
   end
   def get_averages
     output = `free -m` # bash solution - | sed 's/Mem:[^0-9]+[0-9]+[^0-9]+([0-9]+).*$/1/;2q;1d'`
     output = $1 if (output =~ /.*n(.*)n.*n.*n/) #let live second line
     output = $1 if (output =~ /.*:s+S+s+(S+)s+/) #second field
     render :text => "Usage mem is "+output+"MB RAM."
   end
end


And thats all to watch your server usage.

I start maintaining yast2-repair and first bug which I start solving is that repair from DVD menu doesn’t work same as from installation menu. Find where is problem and also test if fix is correct is not trivial. I describe below how to modify inst-sys on DVD or software on LiveCD.

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Because no one reported any bugs to perl-Bootloader, I have some free time. I use it to improve bash completion for zypper, because I find current one have some really annoying things. In short now completion work also for zypper global options, hint also for short version of commands and help name of repo, service and lock, if you use command which takes that as argument. Next few paragraphs contain practical examples how it help improve your command line productivity, how to get it to your system and also some notes how I implement it. (more…)

I start with history. After 11.0 I became maintainer of perl-Bootloader (I never before write anything in perl, but know some other scripting language, so it is not so hard learn another one) after Alexander. Problem is that alexander doesn’t have enough time for maintainer it (he is also leader of arch team). This mean I get many unresolved bugs (around 150), because lack of resource prevents fixing it. Also I get some features to implement and some enhancement I found enough useful (some idea start in bug reports or on factory mailing list, so thanks community) to implement it. I describe what succeed and what not in rest of this blog entry. (more…)

I try testing xfce4 desktop and find some bugs. But I also find that some really interesting missing in opensuse build service, so I add two new applications to build service (gnome community repository…but now gaupol is available only in my personal repository, because in gnome pygtk wait for python 1.6) – osmo and gaupol.
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Perl-Bootloader response for kernel post-install bootloader update script. Current target is ensure, that you have in your bootloader actually kernel and also that entries for old kernel is removed. This is problematic for some complex or manually enhanced configuration. In this case perl-Bootloader should somehow break your settings (this mean you still can boot, but your enhancement or extra sections can dismiss). This should change in future as noticed in bugzilla .

If you want maintain your configuration manually, you can simple set your bootloader to none. There is two ways how you can do it. First is set LOADER_TYPE=”none” in /etc/sysconfig/bootloader. Second is set this in yast2 bootloader. Another advantage is that this take almost no-time, so if obtain hardware configuration for update take to much time, this is workaround.

Warning, if you set bootloader type to none you must manually edit your bootloader configuration after kernel update. What can help you, is set image and initrd to symlinks which lead to actual kernel.

Maybe someday you try zypper dup to actualize your distribution and in middle of process it fail, because you are disconnected or some packages is actualized before you download it (especially on factory this can happen). It is more safety download packages at first and then install from this local files.

How todo this is little tricky, at first you must enable caching downloaded files (I do it only for remote connection):

zypper mr –keep-packages –remote

So now you cache all downloaded files and now try testing run of dup. Trick is that all packages download for that test is cached.

zypper dup –dry-run

Now if you have slow connection I reccomend also disable autorefresh for all repositories, because if repository is refreshed before dup, you can easily find that some packages is newer than package in cache and you must download it.

zypper mr –all –no-refresh

Now is everything prepared for zypper dup, which use files from cache. Cache can take quite lot of disk space, so after dup you can clean it.

zypper clean

And thats all. This features work from OpenSuse 11 and you can also use this trick for zypper update or zypper install.