Thursday, April 3, 2014

Developers vs Humans

The bits of modern desktop environments I sometimes see send me into the depths of despair. All familiar ways of modifying the system behaviour fail. No more scripts. No more pipes. No more rc-files.

My monitor is usually rotated 90° clockwise. Books and magazines look better this way. To rotate the picture, I usually edit /etc/X11/xorg.conf. The exact spell depends on the video card. Now, it says:

Option "Rotate" "left"

Once upon a time, after an OS upgrade, it stopped working. That is, GDM was displayed in the usual landscape mode. If Xorg was started with 'startx', the orientation was correct, but GDM refused to note the "Rotate left" option. And the display remained that way even after the control was passed from GDM to the window manager. For many days I had to type xrandr --rotate left every time I logged in. I was sure that the problem was in Xorg settings. Then, one day, I decided to install a different desktop manager, Slim. And it suddenly appeared in the right way, in portrait mode! So, the problem was in the GDM settings, but I just couldn't find them. I still haven't and I never will. But the logic of the developers who made that piece of crap to pay no attention to the X11 configuration files, escapes me.

By the way, the switch to Slim solved another problem. I never liked the dumb default notification daemons in Ubuntu, NotifyOSD and KNotify. I'd like to switch to much more configurable 'dunst' notifications, but I couldn't get rid of knotify4, which was started automatically. But in the end I found the place where it was defined: /usr/share/dbus-1/system-services/org.kde.knotify.service I can only ask: how was I supposed to find this place or to change the defaults? Or was I supposed not to change them at all?

Now, tell me, please. Did the developers think they were doing the right thing when they took these decisions? Why do distribution owners accept these weird, uncomfortable and unconfigurable solutions? And, finally, isn't it the reason why modern Linux failed on the desktop?

Monitoring multiline logs by email in full color

I use tools like 'logwatch' and 'logcheck' to monitor new events in logs, but they have serious drawbacks. It is most obvious when it comes to multiline logs like PHP error log or MySQL slow log.

So, I wrote a trivial script that would send email messages with new events from the logs. Besides, the messages must be htmlized/colorized, highlighting the SQL/PHP syntax.

So, here's the script:


L=$(/usr/sbin/logtail2 -f $2 )
if [ "x$L" != x"" ]; then
        echo "${L}"|source-highlight -s $3 -f html|mail $1 -a "Content-type: text/html" \
-s "$(hostname): $2" fi

The syntax is: logmail <recipients> <log file> <syntax>

To extract only new events from the log, I use 'logtail2' from 'logcheck' package. For syntax highlighting I chose 'source-highlight' (it was also used to highlight the script code above).

So, to process MySQL slow log, call the script like this:

logmail /var/log/mysql/mysql.slow.log sql

Or, to produce a report from the php-fpm slow log:

logmail /var/log/php-fpm.slow.log php

The results may look like this:

# Time: 140403 12:01:14
# Thread_id: 12983054  Schema: dsa  Last_errno: 0  Killed: 0
# Query_time: 12.672162  Lock_time: 0.000246  Rows_sent: 300  Rows_examined: 5604906  Rows_affected: 0  Rows_read: 5604906
# Bytes_sent: 14625
SET timestamp=1396512074;
     , external_document_id
     , DATE_FORMAT(created_at, "%Y-%m-%d") AS created_at
     , source_id
      # status = 'preparsed'
      # AND flag = ""
      #OR (
       status = 'converted'
     document.source_priority DESC
     0, 300;