Getting Image and Flavor information from the Rackspace API

At Gamevy we’re lucky enough to have been accepted onto the Rackspace UK Startup Programme. In combination with that, we’ve been using Ansible to deploy new servers, and perform application deployments.

When you create a new server at Rackspace using Ansible rax module there are two pieces of information you’ll need from Rackspace. One of those is the flavor, this defines the instance type (the configuration of the instance – e.g. how much RAM it is given). The second is the id of the image (operating system) you wish to use to create the server.

To date, we’ve not found an easy way to get this information. Our current method is to use cUrl, get an Access Token, and to then make further requests to the API to get the required information.

Given this is an infrequent task, I normally forget the necessary steps. I thought that by noting them down I might save myself, and others, some time in the future. This post assumes that you already have a Rackspace account, and that you have API access via a key which is associated with your account. If that’s not the case, Sign Up here, and then follow these steps to get your API key.

It’s worth noting that this post focuses on accessing functionality provided by Rackspace UK. If you’re accessing from the US, the steps are the same, but  you’ll need to change the URLs that are accessed. Full information about Rackspace’s API can be found at their documentation site.

Getting An Auth Token

First things first, let’s get an Auth Token. To do this, you’ll need a few pieces of information from your Rackspace account: your username, your API Key and your account number.

Login to your Cloud Control Panel, and in the top right hand corner of the screen you’ll see your username with an arrow pointing down next to it. Clicking on that will reveal a menu at the top of which will be your account number, note that down, you’ll need when you make calls to the API, later.

From the menu, select Account Settings. On the resulting screen, access your API secret and note that too.

Create a file, call it whatever you want, I called mine rackspace-creds.json on your machine (I put mine in my home directory, for ease of access). The file should contain the following:

{
    "auth":
    {
        "RAX-KSKEY:apiKeyCredentials":
        {
            "username": "YOUR_RACKSPACE_USERNAME",
            "apiKey": "YOUR_RACKSPACE_API_KEY"
        }
    }
}

To get your Auth Token, open up a terminal and issue the following command

curl https://identity.api.rackspacecloud.com/v2.0/tokens -X 'POST' \
-d @rackspace-creds.json -H "Content-Type: application/json" | python -m json.tool

I’ve piped the output of the cUrl command through python’s json tool to prettify it. In the response you receive, you’ll need to grab your :

"token": {
            "RAX-AUTH:authenticatedBy": [
                "APIKEY"
            ],
            "expires": "",
            "id": "YOUR_AUTH_TOKEN",
            "tenant": {
                "id": "",
                "name": ""
            }
}

List The Flavors And Images Available To You

Now that you’ve got an Auth Token, you can go ahead and make calls to the API endpoints for Flavors and Images. I’ve pasted the corresponding examples below:

Flavors

curl https://lon.servers.api.rackspacecloud.com/v2/YOUR_ACCOUNT_ID/flavors \
> -H "X-Auth-Token: YOUR_AUTH_TOKEN" | python -m json.tool

Images

curl https://lon.servers.api.rackspacecloud.com/v2/YOUR_ACCOUNT_ID/flavors \
> -H "X-Auth-Token: YOUR_AUTH_TOKEN" | python -m json.tool