Set user-agent string to something that identifies the Azure SDK for Java and its version

[jcookems]

Dev estimate: 5
Test estimate: 5

The Azure Services appear to keep track of the user-agent strings in requests. We should make sure that we are correctly reporting our SDK name and version, so we can get reliable metrics on how people are using the SDK.

[gcheng]

yeah, very good idea! so that we can see the growth graph from different geographic regions.

[guangyang]

Copying from private repo.

Our SDK should identify itself to the services via the User-Agent header, to aid in tracking our SDK usage and to help the service owners understand their client distribution.

Currently, for Java the user agent string appears to pick up just the Java version:

User-Agent: Java/1.7.0_09

According to Wikipedia, the user agent for browsers typically includes:

• application type,
• operating system,
• software vendor,
• software revision

For comparison:

1. The .NET Storage Client uses:

User-Agent: WA-Storage/1.7.0

1. The .NET Media Service client just uses their host's default agent string:

User-Agent: Microsoft ADO.NET Data Services

I imagine that we'd want to use something like:

User-Agent: Microsoft Windows Azure SDK for Java/0.3.2

[jcookems]

In addition, need to support users to append extra information to the string. We need to make the tests have a distinct string, so that just running lots of unit tests does not skew the natural usage numbers.

[guangyang]

This is what I propose. Windows Azure SDK/<major version> (<language>; <minor version>; <API level>)

[gcheng]

Finally, the team decide on the following design azure-sdk-for-java/0.4.0

[jcookems]

This breaks the unit tests for me when:

1. Building in Eclipse, without using Maven explicitly from the command line.
2. Using Java 1.7.

Get this error:

com.microsoft.windowsazure.services.core.ConfigurationException: java.lang.reflect.InvocationTargetException
    at com.microsoft.windowsazure.services.core.DefaultBuilder$1.create(DefaultBuilder.java:135)
  ...
    at com.microsoft.windowsazure.services.blob.BlobServiceIntegrationTest.setup(BlobServiceIntegrationTest.java:122)
  ...
Caused by: java.lang.reflect.InvocationTargetException
  ...
    at com.microsoft.windowsazure.services.core.DefaultBuilder$1.create(DefaultBuilder.java:126)
    ... 25 more
Caused by: java.lang.NullPointerException
    at java.util.Properties$LineReader.readLine(Unknown Source)
    at java.util.Properties.load0(Unknown Source)
    at java.util.Properties.load(Unknown Source)
    at com.microsoft.windowsazure.services.core.UserAgentFilter.getVersionFromResources(UserAgentFilter.java:94)
    ... 30 more

Debugging into the issue, in UserAgentFilter.getVersionFromResources:

        Properties properties = new Properties();
        try {
            InputStream inputStream = getClass().getClassLoader().getResourceAsStream(
                    "META-INF/maven/com.microsoft.windowsazure/microsoft-windowsazure-api/pom.properties");
            properties.load(inputStream);
            version = properties.getProperty("version");
            inputStream.close();
        }
        catch (IOException e) {
            version = "";
        }

The inputStream is null for my setup.

EXPECT: No matter how weird the client setup, this code should never throw, Consider replacing the current catch with one that catches everything.

Also, I wonder if the default value of version should be unknown, because I'm getting this user-agent string

User-Agent: Azure-SDK-For-Java

Seems like it would be better to know that the version could not be determined, rather than unlisted.

[gcheng]

To avoid duplication of version number, that pom.properties is the recommended place to fetch version number from maven project...

[gcheng]

for some reason, on Jason's machine, that file is not populated from the build...

[gcheng]

verified, indeed, the whole META-INF directory is missing from the Eclipse Maven build...

[jcookems]

Now the tests run on my machine, and verified that the build from the Jenkins server contains the necessary information.