Category: Linux

I thought I’d take another shot at reducing our build times. When we test our full legacy code, there’s a lot of slow integration tests involving mysql. I looked at using an in-memory database like H2-with-mysql-syntax but some of our code (e.g. table creation) is too mysql-specific. Next step: use a ram disk for Mysql. This is all based on Ubuntu 12.04.

Here’s a script that starts MySQL with the parameters to use /dev/shm for all files, and bootstraps in the root user and system tables. I have verified using iotop and iostat that nothing is written to actual disk with these settings.

As for performance? a full test run of our main data access library has gone from 4:11 to 3:41, about 11% faster. Not much really!

A.K.A Keeping Your WordPress in Git

As a web application developer I’m used to having several environments to deploy to: my local workstation, the QA testing environment and our production environment. I’m also accustomed to keeping everything in version control: code, config and deployment scripts. As we prepare a new release it spends time in the QA environment and when testing is complete we move it to production. The method for deploying to QA is very similar to how we deploy to production, since we want to catch bugs in the deployment process itself.

This technique is not obviously applied to WordPress deployment. Over the years I have developed a technique for hosting a WordPress ‘development’ environment for our marketing and frontend webdev people to work on before it is release to the public. We keep all the changes in git and deploy directly from git in one command. I haven’t seen any other great solutions to the problem that a lot of your content is in the database, but a whole bunch of stuff is also in the theme files (php and js), so you need to ‘deploy’ the database changes alongside the file changes. Here’s my take on that.

Caveat

This technique BLOWS AWAY the production database during deployment. It is therefore not useful if you have comments enabled in WordPress. We use WordPress more like a CMS than a blog so we are free to replace the database when we deploy. The technique could probably be adapted to only deploy the essential tables (pages, posts etc) and leave the comments table alone.

Usage

Let’s assume the development environment is at /var/www/dev and the production environment is at /var/www/prod.

To ‘checkin’ the dev version

cd /var/www/dev
dump-n-push


To ‘checkout’ the current version into production

cd /var/www/prod
deploy


Set Up

Download the scripts from https://github.com/werkshy/wp-deploy and copy them to /usr/local/bin, which should be in your $PATH.

Everything is checked into git: wordpress files, themes, plugins, db dumps, everything.

Install wordpress in the dev environment

Download and unzip the wordpress release at /var/www/dev.

You’ll need to setup the dev database.

mysql -uroot -p
mysql> create database wpdev;
mysql> grant all on wpdev.* to wordpress identified by 'wordpress';


Set the db parameters in wp_config.php. THIS WILL NOT BE CHECKED IN.

Edit .gitignore, most importantly to block wp-connfig.php:

/wp-content/cache/
.DS_Store
/wp-config.php
.htaccess


Set up your webserver to serve php from that directory as normal, (see example Apache configs at the end of this post).

Add Everything To Git


cd /var/www/dev
git init
git add -A
git commit -m "initial commit"


Create the ‘origin’ repository

You may keep your site on a remote git repo, or in a git repo on the local machine.

Create the ‘origin’ repository:

cd /root/
mkdir wp.git
cd wp.git
git init --bare


Push your dev commit to the origin

cd /var/www/dev
dumpdb
git remote add origin /root/wp.git
git push


Prepare the production environment

Checkout the files:

cd /var/www
git clone /root/wp.git prod
cd prod
cp /var/www/dev/wp-config.php .


Create the production database (use the same user as the dev one)

mysql -uroot -p
mysql> create database wpprod
mysql> grant all on wpprod.* to wordpress;

Set the production db name in wp-config.php

Now try loading the db dump into production:

loaddb


If that all works, you can now dump and push the dev site with

dump-n-push

and you can deploy the production site from git with

deploy


Example Apache Config

Development Environment:

<VirtualHost *:80>
	ServerName dev.energyhub.com
	DocumentRoot /var/www/dev
	<Directory "/var/www/dev">
		AllowOverride All
	</Directory>
</VirtualHost>

Production Environment:

<VirtualHost *:80>
	ServerName www.energyhub.com
	DocumentRoot /var/www/prod
	<Directory "/var/www/prod">
		AllowOverride All
	</Directory>
</VirtualHost>

Why Claws Mail?

I’ve been suffering more and more recently on my old Thinkpad maxed out at 1GB of RAM. Also I’ve been feeling the need to use a real mail client after a few
months of having two GMail windows open (work + personal). Trusty old
Thunderbird uses 40+MB of RAM on this machine for three IMAP accounts, using a couple of crucial extensions. 40MB is a large chunk of my precious memory, considering that I’m already using two instances of Firefox (one for browsing, one for web development). If the memory usage hits 1GB then everything grinds for a couple of minutes (swap is so evil on laptops!) until I can kill one of those Firefoxes, so all of my apps have to justify themselves against low memory alternatives. Claws uses about 6MB, so I’m using it for now.

Using Claws Mail with GMail

Claws is remarkably capable as a GMail IMAP client these days. Naturally it supports IMAP over SSL and SMTP over SSL with TLS, which is required for GMail. It also has two features which Thunderbird only supports through extensions or about:config magic settings:

• You can set Trash to be [Gmail]/Trash.
• You can set up a shortcut key to archive emails. This isn’t obvious so here’s how:

1. Create a label in Gmail called ‘archived’. This is just a label where you can put stuff so it isn’t in the inbox (“inbox” in Gmail is just a label too)
2. Go to Configuration/Actions.
3. Add a new action with Menu Name “Archive” and command as a filter action.
4. Edit filter action, set Action = Move, and Destination = archived
5. Save the action. You should now have the action available in the menu under Tools/Actions/Archive and can check that it works.
6. Now, to set a shortcut key, go to Configuration/Preferences/Other/Miscellaneous and set “Enable customisable keyboard shortcuts”. Then go to Tools/Actions, and with the “archive” action highlighted press ‘Y’ to set the keyboard shortcut.

Other settings:

Tell Claws not to save sent mail, because using Google’s SMTP puts a copy in your sent folder anyway.

Set [Gmail]/Sent Mail to type ‘outbox’ and you can delete the other ‘Sent’ folder, plus you get a nice icon on the sent mail folder. You can do the same with Drafts and Trash.

I’m dealing with a lot of documents with the language set to English (South African) this year, and in OpenOffice on Jaunty there’s always a ton of perfectly cromulent words which being flagged as mispelled. On the command line I see an error like this:

Failure loading aff file /usr/share/myspell/dicts/en_ZA.aff

I do have all the relevant packages installed, so it seems like Jaunty has installed a affixes file for myspell that can’t actually be used by OpenOffice at least.

The fix is to download the myspell en_ZA files from here http://downloads.translate.org.za/spellchecker/

Backup the original files

cd /usr/share/myspell/dicts/

sudo mv en_ZA.aff en_ZA.aff.bak

Unzip the file from translate.org.za, and copy it to /usr/share/myspell/dicts/en_ZA.aff, and do the same for en_ZA.dic

That should give you a working spellchecker in OpenOffice.org

Here’s an update to ‘picflick’ the Picasa-to-Flickr uploader for Linux.

The changes are mainly simplification and documentation. I had found that my picflick setup broke when I upgraded my Ubuntu version over the holidays, and the previous setup wasn’t showing me why. The new version runs everything in a terminal and skips all the other pointless notification methods (libnotify, text-to-speech and beeping!!) What was I thinking?

Get it at picflick.