Windows Azure Service Management

Unlike on-premise applications, the deployment of a cloud services involves only software provisioning from the developer's perspective. You saw in the earlier examples how hardware provisioning was abstracted from you in the deployment process. In a scalable environment where enterprises may need to provision multiple services across thousands of instances, you need more programmatic control over the provision process rather than configuring services using Windows Azure developer portal. Manually uploading service packages and then starting and stopping services from the portal interface works well for smaller services, but becomes a time-consuming and error-prone process when deploying multiple large-scale services. The Windows Azure Service Management API allows you to programmatically perform most of the provisioning functions via a REST-based interface to your Windows Azure cloud account. Using the Service Management API, you can script your provisioning and deprovisioning process end to end in an automated manner. In this section, I will cover some important functions from the Service Management API and also demonstrate some source code for you to build your own cloud service provisioning process.

1. Service Management API Structure

The Service Management API provides most of the functions you can perform on the storage services and hosted services from Windows Azure developer portal. The Service Management API categorizes the API operations into three primary sections: storage accounts, hosted services, and affinity groups. Operations on storage accounts mainly cover listing of accounts and generation of the access keys. Operation on hosted services cover listing of services, deploying services, removing services, swapping between staging and production, and upgrading services. The affinity groups operations are limited to listing and getting properties of affinity groups in your account.

The Service Management API uses X.509 client certificates for authenticating calls between the client and the server.

2. Programming with the Service Management API

To start programming with the Service Management API, you must first create a valid X.509 certificate (or work with an existing one). You can use makecert.exe to create a self-signed certificate

makecert -r -pe -a sha1 -n "CN=Windows Azure Authenticat
ion Certificate" -ss My -len 2048 -sp "Microsoft Enhanced RSA and AES
 Cryptographic Provider" -sy 24 proazureservicemgmt.cer

Next, go to the Accounts section of Windows Azure Developer portal and upload the certificate from Manage API certificate section.

Figure 1. Upload the API certificate

Once the certificate is uploaded, you can call the Service Management REST API by passing the certificate as the ClientCertificate property of the System.Net.HttpWebRequest object, by using the csmanage.exe application from the Service Management API samples, or by building your own application. In Ch3Solution, I have created a sample Windows Application that makes REST calls to the Service Management API. It uses the Microsoft.Samples.WindowsAzure.ServiceManagement.dll file from the service management code samples. The csmanage.exe uses the same assembly to make the API calls. Eventually, the API assembly may become part of the Windows Azure SDK. Figure 2 illustrates the Service Management API windows application.

Figure 2. The Service Management API windows application

In Figure 2, The Service Management Operations section lists the operations that you can invoke on the Service Management API. The output textbox prints the output from the operations. The right-hand side of the user interface consists of input parameters. The input parameters are as follows:

• Subscription Id: You can get the subscriptionId from the Account page of the developer portal. This parameter is required by all the Service Management API operations.

• Certificate Path: This text box points to the API certificate file on the local machine. This certificate must match the one you uploaded to the portal.

• Resource Type: This drop-down lists the types of resource you want to access: Hosted Service, Storage Account, or Affinity Group.

• Resource name: You should type the name of the resource you want to access (e.g., storage account name, hosted service name, affinity group name).

The remaining input parameters are operation dependant. You can choose an operation from the Service Management operations list, enter input parameters and click Execute Operation. For example, to create a deployment in your hosted service account, you can:

The OP-ID shows the operation ID returned by the method call, which you can use to track the operation status. To check the status of the deploy operation, select the Get Operation Status method, and click Execute Operation. The status gets displayed in the bottom window. Once the deployment is complete, you can run the deployment by selecting the Update Deployment Status method and selecting the "running" option from the deployment status drop-down. Similarly, you can execute other operations from the Service Management API.