MySQL Linux CLI command execution
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
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
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
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
Or
find /loc/of/sessions -ctime +1 -type f -exec rm -v {} \;
bind refuses to restart, debian squeeze
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
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!
Invalid method in request \x16\x03\x01
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
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!
Eaccelerator mirror / downloads
Eaccelerator is insanely useful in my line of work. However, their main downloads are down right now, so I’m mirroring the latest version here:
http://kirrus.co.uk/stuff/eaccelerator-0.9.6.1.tar.bz2
http://kirrus.co.uk/stuff/eaccelerator-0.9.6.1.zip
You can see the files sha1sums here: https://eaccelerator.net/wiki/Release-0.9.6.1
Alternatively, if you’re scripting (we are), you can use the following to get my (‘up-to-date’) version:
http://kirrus.co.uk/stuff/eaccelerator-latest.tar.bz2
bz2.. because that’s the version we use here 
Quick useful sysadmin stuff
Two useful things I have found or use
Firefox Awesomebar search trick
A wonderful tip, that someone sent into the ubuntu-uk podcast. (I can’t remember who, or the episode. Comment if you know and I’ll credit them here! )
You can search, in any website’s search function, using firefox’s address bar. Now, at first glance this sounds really boring and useless, but it really isn’t, at all.
First, we need to find a website to search. Let’s use launchpad’s bugs search, for Ubuntu. So, we go here:
https://bugs.launchpad.net/ubuntu/
Then, right click on the search box, and click “Add a keyword for this search”. This brings up the standard bookmark – your search keywords are stored as a bookmark. Give it a useful name, something to help you next time you go sorting through your book marks. Now, the keyword is how we use this trick. I’m going to use “bugs”, but you can use anything you want, just remember, this is the word you put before your search string in the address bar. Click Add.
Now, all we have to do, is to search for a bug. Let’s use the classic bug 1.
Open a new tab (CTRL + T), then in the address bar type [your keyword] microsoft market share, and hit enter.
Lo and behold:
Testing SMTP-AUTH the fast way
Found a really handy little command line program called “swaks”. Great if you’ve ever needed to test SMTP-AUTH, and didn’t want to have to base64 the username and password yourself. Here’s a quick rundown on the command and flags I use with them. (Should be fairly obvious, comment if not!)
swaks -s [smtp-server-name-or-ip] -au [smtp-auth-user] -ap [smtp-auth-password] -f [from-address-of-testing-email]
Hit enter, and it’ll ask you the “to” email address. Type it in, and it gives you the full connection readout, just as if you were doing it with telnet (or netcat) on the command line:
<- 220 smtp.our-domain.com ESMTP
-> EHLO gemini
<- 250-smtp.our-domain.com
<- 250-AUTH LOGIN
<- 250-AUTH=LOGIN
<- 250-PIPELINING
<- 250 8BITMIME
-> AUTH LOGIN
<- 334 Z29vZCB0cnkgOikK
And so on.
