Passing Parameter from Http Trigger to Orchestration function

Question

I am developing an Azure Durable Function using .NET 7. The HttpTrigger receives a payload in the POST method.

[Function("CreateCandidateProfileOrchestration_HttpStart")]
public static async Task<HttpResponseData> HttpStart(
    [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestData req,
    [DurableClient] DurableTaskClient client,
    FunctionContext executionContext)
{
}

The payload should be passed to Orchestration method as parameter:

[Function(nameof(CreateCandidateProfileOrchestration))]
public static async Task<List<string>> RunOrchestrator(
    [OrchestrationTrigger] TaskOrchestrationContext context)
{
}

What would be a standard way to achieve that?

Any example code would be appreciated.

Thanks. Ruhul

Answer 1

I tried the code below to pass a parameter from an Http Trigger to the Orchestration function.

Code :

using System.Collections.Generic;
using System.IO;
using System.Net.Http;
using System.Net.Http.Headers;
using System.Text.Json;
using System.Threading.Tasks;
using Microsoft.Azure.WebJobs;
using Microsoft.Azure.WebJobs.Extensions.Http;
using Microsoft.Azure.WebJobs.Extensions.DurableTask;
using Microsoft.Extensions.Logging;

public class MyPayloadType
{
    public string Property1 { get; set; }
    public int Property2 { get; set; }
}

public static class CreateCandidateProfileOrchestration
{
    [FunctionName("CreateCandidateProfileOrchestration_HttpStart")]
    public static async Task<HttpResponseMessage> HttpStart(
        [HttpTrigger(AuthorizationLevel.Anonymous, "post")] HttpRequestMessage req,
        [DurableClient] IDurableOrchestrationClient client,
        ILogger log)
    {
        string requestBody = await req.Content.ReadAsStringAsync();
        var payload = JsonSerializer.Deserialize<MyPayloadType>(requestBody);
        string instanceId = await client.StartNewAsync("CreateCandidateProfileOrchestration", payload);
        log.LogInformation($"Started orchestration with ID = '{instanceId}'.");

        var response = new HttpResponseMessage();
        var content = new JsonContent(new List<string> { "Started orchestration." });
        response.Content = content;
        return response;
    }

    [FunctionName(nameof(CreateCandidateProfileOrchestration))]
    public static async Task<List<string>> RunOrchestrator(
        [OrchestrationTrigger] IDurableOrchestrationContext context,
        ILogger log)
    {
        var payload = context.GetInput<MyPayloadType>();
        log.LogInformation($"Received payload: {payload.Property1}, {payload.Property2}");

        return new List<string> { "Orchestration result" };
    }

    [FunctionName("ActivityFunction")]
    public static async Task<string> ActivityFunction(
        [ActivityTrigger] string input, ILogger log)
    {
        return $"Activity completed with input: {input}";
    }
}

public class JsonContent : StringContent
{
    public JsonContent(object value) : base(Newtonsoft.Json.JsonConvert.SerializeObject(value))
    {
        Headers.ContentType = new MediaTypeHeaderValue("application/json");
    }
}

Output in Postman:

Follow these steps to get the output in Postman:

URL:

http://localhost:7260/api/CreateCandidateProfileOrchestration_HttpStart

JSON body:

{
  "Property1": "Value1",
  "Property2": 42
}

Output data in Postman:

[
    "Started orchestration."
]

Terminal Output:

I received the payload details in the output below.

Functions:

        CreateCandidateProfileOrchestration_HttpStart: [POST] http://localhost:7260/api/CreateCandidateProfileOrchestration_HttpStart

        ActivityFunction: activityTrigger

        CreateCandidateProfileOrchestration: orchestrationTrigger

For detailed output, run func with --verbose flag.
[2024-01-24T06:07:46.885Z] Host lock lease acquired by instance ID '0000000xxxxxxxxxxxxxxxx'.
[2024-01-24T06:08:06.178Z] Executing 'CreateCandidateProfileOrchestration_HttpStart' (Reason='This function was programmatically called via the host APIs.', Id=898a0b0cxxxxxxxxxxxxxxxxxx)
[2024-01-24T06:08:06.392Z] Started orchestration with ID = '94db3fxxxxxxxxxxxxxxxx'.
[2024-01-24T06:08:06.431Z] Executed 'CreateCandidateProfileOrchestration_HttpStart' (Succeeded, Id=898a0b0cxxxxxxxxxxxxxx, Duration=310ms)
[2024-01-24T06:08:06.563Z] Executing 'CreateCandidateProfileOrchestration' (Reason='(null)', Id=0011bc56xxxxxxxxxxxxxx)
[2024-01-24T06:08:06.604Z] Received payload: Value1, 42
[2024-01-24T06:08:06.616Z] Executed 'CreateCandidateProfileOrchestration' (Succeeded, Id=0011bc56xxxxxxxxxxxxxx, Duration=67ms)