Azure WebJob- QueueTrigger Staging and Production

Question

I have an Azure WebJob that will be used for Staging and Production. The keys for the proper environments are set in the app.config file.

A ConfigManager class reads the properties from the app.config file.

 public static string FirstQueue
 {
     get { return ConfigurationManager.AppSettings["FirstQueue"]; }
 }

I would like the QueueTrigger to read the from the proper queue specified in the app.config file.

 public static void ProcessFirstQueue([QueueTrigger(ConfigManager.FirstQueue)] string message)
{
   //some function       
}

However, the QueueTrigger doesn't seem to like this. I get "An attribute argument must be a constant expression, type of expression...." Any suggestions to set this up. I do not want to hard code values in the queue trigger. Thanks

Answer 1

You can resolve the queue name at runtime using the

INameResolver

Here's an example to demonstrate this:

WebJob Code:

public class Program
{
    private static void Main(string[] args)
    {
        var config =
            new JobHostConfiguration("insert connection string")
            {
                NameResolver = new QueueNameResolver()
            };
        var host = new JobHost(config);

        host.RunAndBlock();
    }

    public static void ProcessNotification([QueueTrigger("%queueKey%")] string item)
    {
        //Handle message
    }

    public static void ProcessPoison([QueueTrigger("%queueKeyPoison%")] string item)
    {
        //Handle poison message
    }

}

Here's the QueueNameResolver class:

public class QueueNameResolver : INameResolver
{
    //name = queueKey or queueKeyPoison
    public string Resolve(string name)
    {
        //Use the name to get it from the app.config or somewhere else.
    }
}

Hope this helps,