CODEWITHSUNDEEP
jsonazureazure-functions
Karan Desai
Karan Desai

Reputation: 3142

Dynamically set schedule in Azure Function

I have following function.json for my Azure function whose schedule is set to run at 9.30 daily. What I want is to dynamically set the schedule attribute of this json. This scenario arises when a client who is using my application enters date, on that date-scheduler should run. 

   {
  "bindings": [
    {
      "name": "myTimer",
      "type": "timerTrigger",
      "direction": "in",
      "schedule": "0 30 9 * * *" //Want to set dynamically
    }
  ],
  "disabled": false
}

Is this possible?

(Also note, I don't want to use Azure Scheduler due to budgeting reasons)

Upvotes: 16

Views: 9466

Answers (3)

Waqas ali
Waqas ali

Reputation: 278

Its an old question but still relevant. I recently came across a similar issue. Azure function has a built in functionality that you can use. Its called Eternal orchestrations in Durable Functions (Azure Functions). You can do something like

[FunctionName("Periodic_Cleanup_Loop")]
public static async Task Run([OrchestrationTrigger] IDurableOrchestrationContext 
context)
{

await context.CallActivityAsync("DoCleanup", null);

// sleep for one hour between cleanups
DateTime nextCleanup = context.CurrentUtcDateTime.AddHours(1);
await context.CreateTimer(nextCleanup, CancellationToken.None);

context.ContinueAsNew(null);
}

More lnfo can be found at https://learn.microsoft.com/en-us/azure/azure-functions/durable/durable-functions-eternal-orchestrations?tabs=csharp

Upvotes: 6

Tany
Tany

Reputation: 1322

You could modify your function.json to fetch the cron expression from app settings.

"schedule": "%TriggerSchedule%"

Define TriggerSchedule in your appsettings. You could modify your appsettings dynamically and the function trigger would align to it.

Upvotes: 12

Alexey Rodionov
Alexey Rodionov

Reputation: 1446

  1. Use Kudu API to change function.json https://github.com/projectkudu/kudu/wiki/REST-API

    PUT https://{functionAppName}.scm.azurewebsites.net/api/vfs/{pathToFunction.json}, Headers: If-Match: "*", Body: new function.json content

  2. Then send request to apply changes

    POST https://{functionAppName}.scm.azurewebsites.net/api/functions/synctriggers

Or you can use Queue Trigger with "initialVisibilityDelay" messages. In this case you need to write your own code to implement a scheduler.

Upvotes: 5

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