A JISC-funded Managing Research Data project

Posts tagged Extreme Programming

Orbital is going to be a big bit of software, with lots of things doing lots of other things. A big part of putting together such a large bit of software – alongside our Pivotal Tracker instance – is the regular process of ‘building’ the software from source code into something that can actually be used, testing it and getting it onto our development servers so that we can actually see what it’s doing. As part of Orbital we’re taking a step into what is a relatively unexplored frontier for the development team here at Lincoln – Continuous Integration.

Continuous Integration means that as we develop our software it’s constantly being built, tested and deployed to make sure that it’s behaving as expected. We’re using the popular Jenkins server to manage everything that’s going on as part of this process, as well as provide reports on what’s happened. We’re slowly adding more things to the list of what’s actually happening when the magic starts, but here’s what we’re going to be doing by the end of the project every single time that somebody makes a change to our codebase:

  • Ensure that the source code is available from GitHub.
  • Invoke Phing to do all kinds of additional goodness as part of an automated build, including:
    • Run unit tests on our code using PHPUnit.
    • Verify that the code adheres to certain style standards (We use the CodeIgniter Style Guide) using PHP Code Sniffer. Specifically we’re using Thomas Ernest’s implementation of the guide.
    • Run a whole battery of analysis that looks for messy code structure and duplicate code.
    • Automatically build the technical documentation using DocBlox. This isn’t the end-user documentation, but it does tell us exactly what all our code is supposed to be doing so that we have a reference.
    • Perform token replacement on the resultant codebase. This means that we can keep the code repository clear of all environment and institution specific configuration, since these are replaced as we perform a build.
  • Deploy the built codebase to our development and testing platform so that we can actually use it.
  • Tell us the results of all of the above in a variety of pretty graphs and reports.

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As part of Orbital’s development we need to keep what we’re doing on track, and ensure that what is produced is actually what people are after. We’re building the project using agile development methods, which mean that instead of generating a load of documentation and exacting requirements up front and then building software, we generate a basic set of requirements, start developing and then return to look at new or changed requirements at regular intervals.

Keeping tabs on this kind of thing requires a management tool, and in our case we’re using the wonderful Pivotal Tracker, and here’s why.

Pivotal allows us to break down user requirements (gathered through a variety of means, including meetings, surveys, observation and so-on) into discreet bundles called ‘stories’, each of which represents something that a user needs (or wants) to be able to do with the final product. An example may be “project administrators must be able to assign roles to project users”, or “users must be able to manually add a data point”. By creating these stories it starts to become clearer what actually needs to be done.

From there we can start to fully analyse each of these stories, providing them with information such as a ‘score’ of how difficult to achieve each story will be, or including sub-tasks for actual development purposes. Stories can be assigned to various people based on who needs to be involved, and go through a clearly defined workflow of being started, being finished, being delivered in a product version and being approved by the customer.

On top of this management of user stories we can also pack out Pivotal with higher-level package deliverables and deadlines, along with bug reporting and general project chores. Once we’ve got all these things into the Tracker we’re able to re-order them as priorities shift, giving us an instant overview of what’s happening in the current iteration (a 2-week long development cycle) as well as what’s going to be happening in future iterations. At this point, Pivotal Tracker comes into its own with something called ‘emergent planning’.

Emergent planning takes a look at how we’re actually performing in terms of crunching through our list of user stories and dynamically adjusts which stories we’re going to be tackling in upcoming iterations. If we’re doing well we begin to see more points worth of development per iteration, and if we’re slipping then Tracker gives us fewer. Since we’ve told Pivotal what needs to happen before certain deadlines are met (when we ordered stories and tasks), and since Pivotal knows roughly how fast we’re working, it’s easy to see if we’re predicted to hit or miss development milestones.

Want to see what we’re up to? Our Pivotal Tracker project is open for you all to see.