KeyVault.cs

using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Host;
using Microsoft.Extensions.Logging;

namespace KeyVault
{
    public static class MyFunctionClass
    {
        private static string superSecret = System.Environment.GetEnvironmentVariable("SuperSecret");
        
        [FunctionName("MyFunction")]
        public static void Run([EventHubTrigger("eventhub", Connection = "EventHubConnectionString")]string myEventHubMessage, ILogger log)
        {
            // DISCLAIMER: Never log secrets. Just a demo :)
            log.LogInformation($"Shhhhh.. it's a secret: {superSecret}");
        }
    }
}