How To: Manually Running Azure Functions that Use Timer Triggers

I have an Azure Function that runs using a Timer Trigger.

This function invokes a service class that performs some period automated tasks for the free journal and mood tracking micro-SaaS https://dailytracker.co I recently shipped.

I was testing it using a separate HTTP Trigger method but for quick tests wanted a way that didn’t involve opening Postman.

You can see the function here:

//runs every hour
[FunctionName("GenerateAnalytics")]
public static void GenerateFromTimer([TimerTrigger("0 0 * * * *"
                  #if DEBUG
                  , RunOnStartup = true
                  #endif
)] TimerInfo myTimer, ILogger log, ExecutionContext context)
{
  if (myTimer.IsPastDue)
  {
      log.LogInformation("Timer is running late!");
  }

  var config = new ConfigurationBuilder()
                  .SetBasePath(context.FunctionAppDirectory)
                  .AddJsonFile("appsettings.json", optional: false)
                  .AddEnvironmentVariables()
                  .Build();

  var cfgValues = config.GetSection("values");

  log.LogInformation("C# Timer Trigger function processed a request.");

  TextAnalyticsService analyticsService =
      new TextAnalyticsService(cfgValues["TextAnalyticsEndpoint"],   cfgValues["TextAnalyticsAPIKey"]);

// invoke analytics
analyticsService.ProcessAnalytics();

log.LogInformation($"C# Timer trigger function executed at: {DateTime.Now}");
}

The cron expression 0 0 * * * * invokes the function every hour.

The following command/parameter runs the function on startup or when running in debug mode / via Visual Studio:

#if DEBUG
, RunOnStartup = true
#endif

Not the prettiest syntax but helpful if you just want it to run when your debugger launches.