Writing your first OpenStack application

Let's begin by writing a simple application that lists the available VMs running on your OpenStack Compute service node.

We first need to import the OpenStack library into our application program. We will import the Connection class into our program to demonstrate how we can use it. The application program must establish a connection to the OpenStack cloud. This is achieved by creating an object of the connection class and passing the security information and credentials to the constructor of this class. We must pass the following information to the constructor:

• auth_url: The keystone authentication URL. This is the URL of your OpenStack keystone service. It is usually set to the IP address or domain name of your OpenStack Keystone node and it is appended with /identity.
• project_name:  This is the name of the project that you want your program to operate in.
• username: The name of the user who will be logging into OpenStack via the application program...