For a little while now I have been using the online todo list Remember The Milk to keep track of the numerous disparate tasks and projects I’ve got going on at any one time.

Using lists, tags and smart searches I’ve managed to not only never lose track of a task. I estimate this has made me about a billion times more efficient, and has reduced stress levels a thousand fold.

Additionally, I use the new and increasingly indispensable ifttt beta to automate a bunch of tasks around the internet; e.g. to grab a copy of Facebook pictures I get tagged in, send me an SMS when the there’s a problem on my girlfriend’s route to work, etc.

Every so often something happens on the internet and, rather than undertaking a specific action, you want to be prompted to undertake some appropriate action. Wouldn’t it be sweet if when these things happened you could have a virtual PA drop a note on your daily todo list?

Twitter to the rescue!

Sadly, Ifttt doesn’t have a Remember the milk channel (yet) but, like many web apps, Remember the milk has a twitter bot. If you add this bot as a friend and associate your RTM account with your twitter account you are able to add things to your task list by sending the bot a direct message.

Ifttt has a twitter task, so all you need to do to add something to your task list when an action is triggered is begin the twitter message with “d rtm”, e.g.

d rtm Write about Latakoo’s latest blog ^today #work

You can use RTM markup in your message to control what list it goes to, set due dates etc.

My standard use case is to prompt me to write a blog post in response to a client updating their blog, or to tell me cover my car’s windscreen when it’s forecast to snow the next day. I’m sure there’s much more you can do with it!

Apple Airprint is a technology (a zeroconf implementation under the bonnet) which allows apple devices to detect, configure and print without any overt configuration on the part of the user.

The bad news is that in only works for a handful of printers natively. But never fear, Linux to the rescue!

At this point I’m going to assume that you have a Linux box somewhere on your network acting as a file and print server (pretty regular kit in most geek homes).

Set up your printer

The first step is to set up CUPS on your linux server and then installing the appropriate printer driver for your printer.

I won’t go into detail here as there are numerous guides out there on the wider web, but mostly this is a matter of installing cups and foomatic and then visiting the cups configuration website on the server (localhost:631 usually) and adding your printer.

Make sure that the printer is shared. Print a test page.

One gotcha I found is that my default configuration only allowed connections from the local machine, even though the printer was marked as shared (although frankly I was cheating since most of my computers printed to my server over a Samba relay, but that’s by the by).

Take a look at /etc/cups/cupsd.conf and make sure that has an Allow From from your local network. E.g.


<Location />
Order Deny,Allow
Deny From All
Allow From 127.0.0.1
Allow From 192.168.0.0/24
</Location>

Export the printer

The next step is to install the zeroconf demon, which is called Avahi. This varies from system to system, but on debian this is pretty much a matter of apt-getting avahi-daemon. You may also want avahi-discover so you can browse the exported devices on your network.

Assuming you’ve correctly set up and shared your printers in CUPS the next step is to generate an avahi configuration for it. Thankfully, there’s a handy Python script called airprint-generate, available on github which does much of the donkey work.

Copy the resultant file to /etc/avahi/services and restart the avahi demon.

If your printer is password protected, you will want to add a <txt-record>air=username,password</txt-record> field to the file before doing so. Where username and password is the literal cleartext strings sent.

Profit!!!

Theoretically that should be it. After the configuration, and restarting the various demons involved your printer should be available to the various iOS devices kicking around your network.

Let me know if you have any questions!

Amazon, who are most widely known for their online shop, has another project called Amazon Web Services (AWS) offering website authors a collection of very powerful hosting tools.

This is not a sideline for Amazon – a recent conversation I had with an Amazon guy I met at a Barcamp revealed that in terms of revenue AWS exceeds the store – and it dramatically lowers the cost of entry for web authors. Using AWS it is possible to compete with the big boys without the need to mortgage your house for the data center and it solves many storage and scalability problems, what’s more – its pay as you go.

To be clear then, Amazon is now a hosting company, and its rather curious as to why people (Amazon included) are not making a big deal of this.

Anywho, I’ve recently had the opportunity to work on a few projects which use AWS extensively, and since I did run into a few gotcha’s I’d thought I’d jot some notes down here, more as an aide-mémoire as anything else.

Getting an AWS account

Before you begin, you’re going to need an account. So, head over here and create one.

Creating a server

You are going to want to create a server to run your code on. The service you need here is Amazon Elastic Compute Cloud (EC2), so sign up for EC2 from the AWS Management Console.

You are going to have to select an EC2 Image to start from, and there are a number of them available. An Image (called AMIs) is a snapshot of your server, its disks and any software you want to run. Once configured you can start one or more Instances of it, which are your running servers.

Once you’ve configured your server, you can create your own image which you can share or use to boot other instances. This whole process is made infinitely easier by using an EBS based image. EBS is a virtual disk, these can be added like normal disks to your server – sizes 1GB to 1TB. EBS backed images store data to these disks and so configuration changes are preserved, additionally new server images can be cloned with the click of a button.

You can add extra disks to your server, but they must be in the same availability zone (datacenter) as your EC2 image and currently can’t be shared between EC2 instances.

So:

• Save your sanity and use an EBS backed image – if you’re looking for a Debian or Ubuntu based one, I recommend the ones created buy Alestic. You can search for community managed images from within the management console, be sure to select EBS backed! For reference, the AMI I often use is identified as ami-209e7349.
• Grab an Elastic IP and assign it to your image, point your domain at this.
• Your goal is to build an AMI consisting of a ready to go install of your web project, so install the necessary software.
• Note however, that you want to build your AMI so that you can run multiple instances of it in order to handle scalability. Since EBS disks can’t be shared you may have to change your architecture slightly:
  • Don’t store user data on the server – user icons etc – these can’t be shared across instances. Store these instead on Amazon S3 and reference them directly using URL where possible. Note, temporary files like caches are probably ok.
  • If you use a database, use MySQL, but only install the client libraries on your image – you won’t be using a local server (see below)!

Once you’ve configured your server create an AMI out of it, this can then be booted multiple times.

Using a database

The database service you will most likely want to use is called Amazon Relational Database Service (RDS) which can function as a drop in replacement for MySQL.

Sign up for it using the management tool, create a database (making note of the passwords and user names you assign) and allow access from your running server instance(s) via the security settings.

The database is running on its own machine, so make a note of the host name in the properties – you will need to pass this in your connect string.

Conclusion

AWS is a powerful tool, if you use it right. There is a lot more complexity to cover of course, but this should serve as a start.

I’ll cover the more advanced scalability stuff later when I actually get to use them in anguish (and get the time to write about it!)