current360 / puewue-backend

The back-end to a simple application that displays Facebook's datacenter power consumption and other information.

Facebook Power

Simple application that displays Facebook's datacenter power consumption and other information. Use this in conjunction with the front-end project

Development requirements

To run this application locally, you will need:

• Ruby 1.9.3 (see patchlevel in .ruby-version)
• Bundler (gem install bundler)
• Foreman (gem install foreman)
• ElasticSearch (compatible versions 0.20 to latest 1.3.x)
• Redis

Installing dependencies

Thanks to Bundler, installing dependencies is easy. Simply run bundle install inside the root of the application.

Running the application locally

Before running the application, please start ElasticSearch first by doing:

bin/elasticsearch -f

Later you can Ctrl+C to stop it.

Once dependencies have been installed, you can run the application locally by doing:

foreman start -f Procfile.dev

That will start web and other defined process needed during development.

You will normally access the application by visiting http://localhost:5000/ (Port 5000 is the default by foreman)

Populating local data

To test the application locally, it will be necessary populate ElasticSearch with enough information to generate histograms.

First, start ElasticSearch, then reset measurements index by running:

rake db:reset

Next, you would like to populate the index with some fake data, so run:

rake db:populate

Which will generate enough data going back 5 days by default. You can generate more data by providing an option to db:populate:

rake db:populate[10]

To generate 10 days back of data.

If you want to populate recent (less than 24 hours), use 1 as option.

After this, the data is processed as timeline and available at the following URL:

http://localhost:5000/timeline/center-1/24-hours.json

Where center-1 represents the Datacenter and 24-hours the time period to be used.

Please see timeline.rb for other available periods.

Configuration and environment variables

This project follows the principle of Twelve-Factor App design, so no configuration file is stored in the repository.

All configuration is loaded from environment variables.

To avoid forcing you setup those variables in your environment, you can copy the KEY=VALUE of those into .env.development file, which has been excluded from the repository.

For example, to setup SFTP credentials, do the following:

echo 'SFTP_URL=sftp://me@localhost/data/pue_wue' >> .env.development
echo 'SFTP_KEY=sftp_private.key' >> .env.development

You can overload and customize specific variables when running tests (so your development data doesn't get clobbered).

Simply create .env.test with the environment variables you need, for example, REDIS_URL

# .env
REDIS_URL=redis://localhost:6379/0

# .env.test
REDIS_URL=redis://localhost:6379/2

This will use a different URL when running tests (in this case, a different DB on the same Redis).

You can look at env.sample for other variables used by this application.

Deployment

For deployment instructions, please see DEPLOY document.

Licensing

The source code is licensed under the BSD-style license found in the LICENSE file in the root directory of this source tree. An additional grant of patent rights can be found in the PATENTS file in the same directory.