Goweb Application

Simple application demonstrating how CloudFoundry-based clouds can host web applications written in Go language.
It does simple maths like calculating prime factors of a number and listing the first N prime numbers.

You can use the following clouds for testing:

• IBM Bluemix
• Pivotal.

You can play with an instance of the app running in Bluemix at this link, as well as getting the code from JazzHub at this link.

Once you get the code you can run Goweb directly on your desktop: the only requirement is the Go Programming Language binary distribution that you can download from the official site.

Thereafter the instructions on how to deploy a Go App on CloudFoundry-based clouds. Feel free to take them as example for deploying your own app.

Creating the deployment artifacts

Once you have done with the code, you need to create a couple of files on the root folder of your app before deploying it in the cloud:

• .godir
  The file should contain the desired name of the final go libary. E.g.:
  example.com/goweb

  NOTE - CloudFoundry may ignore files beginning with .. In that case rename .godir to _godir

• Procfile
  The file contains the command to start the web app. E.g.:
  web: goweb

Deploying the app

Unless your cloud provide support for Go language, you need to use a custom buildpack to deploy a Go web application.

The one used in the example below has been modified to work with CloudFoundry-based clouds by Michal Jemala. Though this is an experimental Cloudfoundry buildpack for Go, it does its job well (at least on Bluemix and Pivotal clouds).

So, login to your cloud and run the cf command below from the root folder of your application:

cf push goweb -b https://github.com/michaljemala/cloudfoundry-buildpack-go

To deploy this Goweb application run the script .push-this.sh that you should find on the root folder: it performs some preparation steps before calling the cf push.

./.push-this.sh

This is what you should get to your console:

...
0 of 1 instances running, 1 down
0 of 1 instances running, 1 starting
1 of 1 instances running

App started

Showing health and status for app goweb in org your.name-org / space dev as [email protected]...
OK

requested state: started
instances: 1/1
usage: 256M x 1 instances
urls: goweb.mybluemix.net

     state     since                    cpu    memory         disk
#0   running   2014-02-04 06:18:38 PM   0.0%   1.5M of 256M   8.7M of 1G