Image by phill.d

Here’s a few initial thoughts on the experience:

• Keep your mouth shut, unless you want to snack on flies
• Other cyclists sometimes nod and smile
• Cycling gear and accessories are seriously overpriced
• Things that claim to be a “universal fit”, probably are not and may require extensive bodging
• I’m not arriving at work all sweated up, so personal hygiene isn’t the problem I expected it to be
• Cycling in very heavy traffic is easier than I thought because the cars aren’t moving
• Panniers beat backpacks hands down
• 8 years car driving helps with understanding how motorists are likely to interact with you
• Drivers give more room and slow down when there isn’t a cycle lane
• I’m £3.40 a day better off
• I miss listening to podcasts or music on the way to work
• I arrive at work much more awake, and strangely, I no longer crash and resort to strong coffee mid-afternoon

Time-wise, I’m 30 minutes better off in the mornings which makes for a much more relaxed start to the day. My home journey is uphill and I only save 15 minutes compared to using the bus, but this 15 minute saving is negated by the need to shower when I get in.

With regard to accessories and equipment, there appears to be two distinct markets. The first covers casual cyclists and consists of cheap crap, which doesn’t appeal at all. The other market consists of high-end enthusiast products for those willing to pay ridiculous amounts for ever diminishing performance gains. I want neither. Am I being unrealistic?

I’ve found that, particularly where traffic speed is low, it helps to move into the centre of the lane when approaching junctions to ensure that you’re not pushed around by motorists. Cycling in a more assertive, but not aggressive, manner tends to improve your visibility and co-operation with other road users. Other techniques include pulling out early when passing parked cars, and passing them widely, just as a car driver would, following a good look backwards to check for approaching traffic and to signal that you’re about to change course.

Counter to this, it can be useful to leave the road occasionally when approaching a complex junction where there is heavy, fast traffic. Often, off-road cycle paths exist for this purpose. The danger associated with this is re-joining the road because you will appear out of nowhere to motorists.

Also, if you have a compatible Nokia phone, download Sports Tracker which is an awesome performance monitoring which utilises GPS and OpenStreetMap and can record all your route data along with speed vs. time or altitute vs. time. You can export the data, too.

Autumn’s a great time of year for photography. There’s some really nice light around and the leaves starting to fall. This was taken from the footbridge at Whitehall Waterfront in Leeds at 8:50am.

Whilst many people haven’t heard of nginx, it’s got a fair few success stories to its name and powers some major sites including WordPress.com and FastMail.FM.

With nginx, many operations beyond serving of static files are treated by nginx as a proxy operations, whether it’s passing the request to one or more back-end servers or to a CGI handler such as PHP. For example, the server that runs jamesholden.net also runs a subversion repository but nginx can’t do that by itself, so it passes any requests for the subversion repository to an instance of Apache running behind the scenes. There’s a huge amount of flexibility afforded in how a request is handled.

The configuration file format used by nginx differs from that of Apache in that nginx uses braces to define nested sections and allows conditional tests to determine whether a section of the configuration should be included for a particular request, while Apache uses nested tags in angle brackets to open and close sections.

A basic server configurations looks similar to this:

http {
    server {
        listen 1.2.3.4:80;
        server_name testing.example.com;
        root /var/www;
    }
}

This is analogous to an Apache style <VirtualHost> directive, complete with ServerName and DocumentRoot. The location block is fundamental to tailoring the behavior of nginx as the expression that follows can be used to handle different URI paths in different ways. Without this flexibility nginx would not be able to pass PHP scripts to the fastcgi backend or proxy requests to back-end systems. The location does not need to be a path – it can also be a label which we can use to break out of another location under certain circumstances.

At present, all this basic example above will do is serve static pages from the document root /var/www. If we want to serve PHP files, we would need to include an additional location with a pattern to match requests ending in .php. This would be placed within the server block.

location ~* \.php$ {
    fastcgi_pass 127.0.0.1:10005;
}

Assuming that there is a fastcgi handler living on localhost port 10005, and that the rest of the fastcgi configuration has been included at an earlier point in the config, we can now pass PHP scripts to the fastcgi handler. In the location directive, the ~* indicates that pattern is case-insensitive, and the \.php$ is a regular expression that matches the string “.php” at the end of the request. nginx prioritises the PHP location directive because it uses a regular expression.

You may specify location matches without the use of regular expressions. This can be useful to ensure that static content is handled as a priority. For example:

location = / {
    # Matches only requests for the home page (and only the home page)
    # This can be useful to serve a cached version of the home page on a high volume site, yet
    # allow for dynamic content on the rest of the site
}

location ^~ /static/ {
    # Matches requests beginning /static/
}

location *~ \.bin$ {
    # Matches only files ending in .bin that are not in /static/
}

Only one location will match per request unless we re-write it, so it is not possible to define overrides on anything other than the URI using location directives. You can do this within a directive block though, using conditional statements.

Two useful directives are the “root” directive and the “alias” directive. At first sight, these may seem to be similar, but they are subtly different. For example:

location ^~ /docs/ {
    root /usr/share/web;
    # Requests for /docs/foo.txt will be served from /usr/share/web/docs/foo.txt
}

location ^~ /icons/ {
    alias /var/www/icons;
    # Requests for /icons/error.png will be served from /var/www/icons/error.png
}

A caveat is that the alias directive cannot be used in a location based on a regular expression.

The final type of location directive is a named location. This can be used in conjunction with a “try_files” directive to allow static files to be served, while passing other requests to a CMS such as wordpress, eg:

location / {
    root /var/www;
    try_files $uri @wordpress;
}

location @wordpress {
    rewrite ^(.*)$ /index.php?q=$1 last;
}

location ~ \.php$ {
    fastcgi_pass 127.0.0.1:10005;
}

This works because the @wordpress location transforms the request into a call to index.php. This causes the request to be re-entered, where it will match the third location block and be passed to the PHP fastcgi handler for execution. There are multiple ways of achieving this, however.

We just used the rewrite directive to transform the URL into another. Just like Apache, we can use regular expressions to match particular URLs and to transform the request. A common use for this is to provide redirection from bare domain names to their www counterparts or vice-versa, for example this is used on jamesholden.net to bounce visitors off www.jamesholden.net to jamesholden.net, which is my preferred URL:

server {
    listen 1.2.3.4:80;
    server_name www.jamesholden.net;
    rewrite ^(.*) http://jamesholden.net$1 permanent;
}

In this example, we don’t even need to use a location directive because the entire site is being redirected. The “permanent” parameter on the rewrite rule ensures that nginx issues an HTTP 301 response.

Conditional statements can be used to check server variables from within a location directive. You could use this to prevent image hotlinking as follows:

location ~* \.jpg$ {
    if ( $http_referer !~ ^http://jamesholden.net/ ) {
        rewrite ^(.*) /nostealing.jpg last;
    }
}

location = /nostealing.jpg { }

Requests for .jpg files where the referer does not begin http://jamesholden.net/ will be re-written to /nostealing.jpg. The final empty location ensures that the replacement image is not rewritten itself, otherwise a loop would ensue.

These examples are just the tip of the iceberg of what can be done with nginx, so feel free to share your own examples in the comments section. Thanks for reading!

Part of the walkway is disappeared, and a floor to ceiling hole has been torn into the structure. The pool has been an iconic feature of the Leeds city landscape for over 40 years, but years of neglect and a replacement aquatics centre on the outskirts of town rendered the building redundant and, nearly two years after the doors were closed, it is being torn down to make way for… a car park.

There are more photos from inside prior to demolition on flickr.

Via Todays Big Thing

More of my favourites after the jump, or go to the full flickr set.

Lastly, here’s a big panoramic shot of the main room: (click for embiggenment)

I’ve spent the last couple of nights building up what is probably my favourite kit of all – the 8860 car chassis, which was made between 1981 and 1988. It’s quite a feat of engineering and features seats that move in two axes, a working gearbox, a rear differential and rear suspension and steering that implements the Ackermann principle, which is where the innermost wheel turns inwards more when cornering to prevent the tyres from skidding.

It’s a fantastic kit, and I’m pretty chuffed that I my Lego’s been sufficiently well stored over the years to make it possible to build it up without any missing pieces.

The intent seems to be to foil would-be parking charge dodgers who, like everyone, leave the car park before the free 10 minutes is up and circle round for another go, repeating until the person they’re collecting shows up. The new system makes sure that if you return within 30 minutes, you’re treated as if you never left.

Personally, I find it rather worrying that that sort of information is collected automatically. I don’t see any sign of a privacy policy anywhere. Can you think of any other ways you’re tracked and traced automatically?