Kirrus' Blog

Quote of the Day

Kirrus — Sat, 21 Apr 2012 14:22:00 +0000

But in truth it had not exactly been gold, or even the promise of gold, but more like the fantasy of gold, the fairy dream that the gold is there, at the end of the rainbow, and will continue to be there for ever provided, naturally, that you don’t go and look.

This is known as Finance.

- Terry Pratchett

MySQL Linux CLI command execution

Kirrus — Thu, 15 Mar 2012 18:08:42 +0000

As another aid to my memory, you can run mysql commands on the command line like this:

mysql -u user -p[password] database -e "SELECT * FROM orders;".

You can also send the mysql client commands on stdin:

echo "SELECT * FROM orders" | mysql -u user -p[password] database

Or read them in with a file redirection

mysql -u user -p[password] database < /home/kirrus/orders.sql

That last one is really handy for reading MySQL dumps back into MySQL.

MySQL GRANT syntax oddity, show views

Kirrus — Wed, 22 Feb 2012 19:44:58 +0000

So that I don’t forget: Despite what the documentation says, being unclear (links always have an underscore over there, so it’s hard to tell difference between a linked underscore linked item, and one merely space-separated), you should grant ‘SHOW VIEW’, not ‘SHOW_VIEW’. Additionally, ‘SHOW VIEW’ really needs SELECT permissions as well.

Remember this: find recursion

Kirrus — Fri, 17 Feb 2012 18:31:37 +0000

I keep forgetting. To limit find’s recursion, use:

find . -maxdepth X

Where X is the recursion number. Maxdepth must be before any search selection stuff (type, name, mtime, perm etc).

Deleting lots of tiny files really really quickly

Kirrus — Fri, 03 Feb 2012 16:19:06 +0000

This is the second half of that magento issue. Mainly, after having got a directory with millions of files in it, you can do one of two things.

mv sessions sessions_full && mkdir sessions && chown www-data:www-data sessions

rm -rfv sessions_full

find /loc/of/sessions -ctime +1 -type f -exec rm -v {} \;

bind refuses to restart, debian squeeze

Kirrus — Thu, 02 Feb 2012 13:34:13 +0000

After an upgrade, I’ve noticed a few times that bind has refused to restart or reload, saying:

Stopping domain name service: namedrndc: connect failed: connection refused

This seems to be a permissions bug in debian, quite a long lasting one. In order to cheat-fix it quickly, I do the following:

chown bind:root /etc/bind/rndc.key

chmod 660

/etc/init.d/bind9 restart

That seems to fix it well enough. I think it’s a problem in that bind starts as one user, but runs as another. It may be that 440 are all the perms that are necessary. The debian bug report is here: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=169577

Magento Session Files

Kirrus — Thu, 02 Feb 2012 12:40:19 +0000

Magento (the popular open-source online shop system) likes to store its PHP session files in ~/public_html/var/session/

Most debian servers don’t have that in their cron job that deletes old session files.

So, you probably want to set it to store it’s session files in the default location (/var/lib/php5) or alter your cron job (/etc/cron.d/php5)

Fun!

The wind is not your friend

Kirrus — Thu, 19 Jan 2012 19:56:31 +0000

Cycling home tonight, I had just left work’s place, onto a stretch of road with no streetlights. Picture the scene, it’s just stopped bucketing it down with rain, now spitting. I’m in wet-weather gear, and it’s dark. Quite dark. My backpack has a reflective cover, and I’ve a reflectctive jacket, with a particually annoying LED flashing backlight. (I’m paranoid – shortly will have red LED flashing in my helmet.)

Got out safely, clipped my feet in fine (I now have special shoes that clip onto my pedals), accelerating towards my average 15-17mph on that particular bit of road, the wind decided to push me, hard, towards the edge of the road. A very small shallow there, with a grassy bank. Wheels in the culvert, uncontrollable de-acceleration, equals me flat across the A road, with one car passing me and another just behind it.

Promtly to the sound of car-horns telling me just how close I’d come to getting run over, I dragged myself off the road *sharpish*, and dragged my bike off as quick as I could after I was off. I’ve a couple of very minor abrasions on my ankles. Lucky. Very lucky.

Note to self. When it’s wet and windy, piss drivers off by sticking a meter off from the side. It’s far better than getting run over.

Invalid method in request \x16\x03\x01

Kirrus — Tue, 18 Oct 2011 15:02:00 +0000

So, ran into this one. Firefox is throwing this error, along with ‘SSL_ERROR_RX_RECORD_TOO_LONG’. Turns out, apache was serving plain HTTP on port 443, as it hadn’t been given a default SSL config.

Other causes may be: Corrupted SSL cert (rare). Mis-configured proxy. Not adding “SSLEngine On” after configuring an SSL cert. But mostly, you’re trying to talk HTTPS to an HTTP serving webserver.

`a2ensite default-ssl` (on debian) fixed it. Well, fixed in in that the default server now has a snake-oil self-signed cert, but, you know, fixed it.

Possible missing firmware on debian squeeze

Kirrus — Tue, 18 Oct 2011 12:55:06 +0000

If you get these errors:

W: Possible missing firmware /lib/firmware/rtl_nic/rtl8105e-1.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168e-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168e-1.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168d-2.fw for module r8169
W: Possible missing firmware /lib/firmware/rtl_nic/rtl8168d-1.fw for module r8169

Do this as root (or using sudo):

#  aptitude install firmware-realtek

Win!