dotnet-sdk/examples/Workflow

Dapr Workflow with ASP.NET Core sample

This Dapr workflow example shows how to create a Dapr workflow (Workflow) and invoke it using ASP.NET Core web APIs.

Prerequisites

• .NET 6+ installed
• Dapr CLI
• Initialized Dapr environment
• Dapr .NET SDK

Projects in sample

This sample contains a single WorkflowWebApp ASP.NET Core project. It combines both the workflow implementations and the web APIs for starting and querying workflows instances.

The main Program.cs file contains the main setup of the app, including the registration of the web APIs and the registration of the workflow and workflow activities. The workflow definition is found in Workflows directory and the workflow activity definitions are found in the Activities directory.

Running the example

To run the workflow web app locally, run this command in the WorkflowWebApp directory:

dapr run --app-id wfwebapp dotnet run

The application will listen for HTTP requests at http://localhost:10080.

To start a workflow, use the following command to send an HTTP POST request, which triggers an HTTP API that starts the workflow using the Dapr Workflow client. Two identical curl commands are shown, one for Linux/macOS (bash) and the other for Windows (PowerShell). The body of the request is used as the input of the workflow.

On Linux/macOS (bash):

curl -i -X POST http://localhost:10080/orders \
  -H "Content-Type: application/json" \
  -d '{"name": "Paperclips", "totalCost": 99.95, "quantity": 1}'

On Windows (PowerShell):

curl -i -X POST http://localhost:10080/orders `
  -H "Content-Type: application/json" `
  -d '{"name": "Paperclips", "totalCost": 99.95, "quantity": 1}'

If successful, you should see a response like the following, which contains a Location header pointing to a status endpoint for the workflow that was created with a randomly generated 8-digit ID:

HTTP/1.1 202 Accepted
Content-Length: 0
Date: Tue, 24 Jan 2023 00:02:02 GMT
Server: Kestrel
Location: http://localhost:10080/orders/cdcce425

Next, send an HTTP request to the URL in the Location header in the previous HTTP response, like in the following example:

curl -i http://localhost:10080/orders/cdcce425

If the workflow has completed running, you should see the following output (formatted for readability):

HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Tue, 24 Jan 2023 00:10:53 GMT
Server: Kestrel
Transfer-Encoding: chunked

{
    "details": {
        "name": "Paperclips",
        "quantity": 1,
        "totalCost": 99.95
    },
    "result": {
        "processed": true
    },
    "status": "Completed"
}

If the workflow hasn't completed yet, you might instead see the following:

HTTP/1.1 202 Accepted
Content-Type: application/json; charset=utf-8
Date: Tue, 24 Jan 2023 00:17:49 GMT
Location: http://localhost:10080/orders/cdcce425
Server: Kestrel
Transfer-Encoding: chunked

{
    "details": {
        "name": "Paperclips",
        "quantity": 1,
        "totalCost": 99.95
    },
    "status": "Running"
}

When the workflow has completed, the stdout of the web app should look like the following:

info: WorkflowWebApp.Activities.NotifyActivity[0]
      Received order cdcce425 for Paperclips at $99.95
info: WorkflowWebApp.Activities.ReserveInventoryActivity[0]
      Reserving inventory: cdcce425, Paperclips, 1
info: WorkflowWebApp.Activities.ProcessPaymentActivity[0]
      Processing payment: cdcce425, 99.95, USD
info: WorkflowWebApp.Activities.NotifyActivity[0]
      Order cdcce425 processed successfully!