TraP-Demo

A dead-simple means of setting up TraP in a virtual machine so you can easily try it out on your local machine, whether you run Linux, Mac OSX, or (possibly) even Windows!

Setup

Pre-requisites:

You will need:

• Virtualbox. This provides the virtual machine container. When this is successfully installed you should be able to launch the Virtualbox GUI from start menu (just to check it's working OK - we won't actually be using that inferface).
• Vagrant. Vagrant provides a convenient command line interface for setting up and configuring virtual machines. You can check if vagrant is installed OK by running vagrant help from the command line.
• Ansible. Ansible provides a scripting language and associated tools for system installation and configuration. It's a Python package, so my preferred installation method is to simply install it using pip, but see the installation instructions for other options. You can check if ansible is installed and in your path by running ansible --help from the command line.

Installation:

From the command line:

Clone this repository and navigate to the vagrant directory:

git clone https://github.com/timstaley/trap-demo.git
cd trap-demo/vagrant

Install the Ansible roles - these are 'building blocks' for system configuration, e.g. we use one role to install casacore, another to configure Postgres databases, etc. The required roles are listed in requirements.txt, and we can install them with:

ansible-galaxy install -r requirements.txt

We're ready to go! The Vagrantfile is configured so that vagrant will create a virtual machine running Ubuntu 14.04 and then install TraP and Banana using the Ansible configuration scripts. Simply run:

vagrant up

(from the vagrant directory). This will take a while the first time - perhaps an hour or so depending on your internet connection speed, etc. If something goes wrong (maybe you get disconnected from the internet or whatever) then you can resume the install process using:

vagrant provision

That's also the command to run if you change the configuration scripts and want to bring your virtual machine up to date.

When everything's up and running, try bringing up a web-browser and take a look at http://localhost:8080 - if everything worked OK you should see the front page of the Banana web-interface.

You can also connect to your virtual machine over SSH. Try:

vagrant ssh

Teardown:

Running a virtual machine uses up some of your RAM, and some hard drive space. If you want to 'switch off' the virtual machine and free up your RAM again, run:

vagrant halt

(you can vagrant up later to switch it back on again). If you want to delete the virtual machine entirely and reclaim your disk space, run:

vagrant destroy

Data reduction

The next step is to actually analyse some radio-astronomy images using the TraP. We'll refer to the virtual machine as the 'guest machine' or just 'guest' from here on. (Your regular operating system is the 'host'.)

Vagrant configures the guest machine so that the vagrant folder we've been working from is also visible from the guest, at the path /vagrant. If you vagrant ssh into the guest and then cd /vagrant you can check this for yourself. The setup scripts created a couple of subfolders here, trap-jobs and trap-data. From the host, you should move a copy of your radio images into trap-data (perhaps organised into a subfolder).

Next, we'll configure a TraP job to analyse this dataset. From a guest terminal (To be continued...)