Invoke a function task

  • Article

TFS 2017

Use this task in an agentless job of a release pipeline to invoke an HTTP triggered function in a function app that is created and hosted in Azure Functions and parse the response.

Note

In Microsoft Team Foundation Server (TFS) 2018 and previous versions, build and release pipelines are called definitions, runs are called builds, service connections are called service endpoints, stages are called environments, and jobs are called phases.

Demands

Can be used in only an agentless job of a release pipeline.

Arguments

Parameter Comments
function
Azure function URL		 Required. The URL of the function to be invoked. Example: "https://azurefunctionapp.azurewebsites.net/api/HttpTriggerJS1"
key
Function key		 Required. Function or host key to access and invoke the function. Using a secret pipeline variable to store the function key is recommended.
method
Method		 Required. The HTTP method with which the function will be invoked.
headers
Headers		 Optional. The header in JSON format to be attached to the request sent to the function.
queryParameters
Query parameters		 Optional. the string query to append to the function URL. Must not start with "?" or "&".
body
Body		 Optional. The request body in JSON format.
waitForCompletion
Completion event		 Required. How the task reports completion. Options: "ApiResponse", "Callback."
API response (default) - the function returns success and success criteria evaluates to true.
Callback - the function makes a callback to update the timeline record.
successCriteria
Success criteria		 Optional. The criteria to consider the task successful. By default, the task returns 200 OK status when successful.

Open source

This task is open source on GitHub. Feedback and contributions are welcome.

FAQ

Where should a task signal completion when Callback is chosen as the completion event?

To signal completion, the function should POST completion data to the following pipelines REST endpoint.

{planUri}/{projectId}/_apis/distributedtask/hubs/{hubName}/plans/{planId}/events?api-version=2.0-preview.1

**Request Body**
{ "name": "TaskCompleted", "taskId": "taskInstanceId", "jobId": "jobId", "result": "succeeded" }

See this simple cmdline application for specifics. In addition, a C# helper library is available to enable live logging and managing task status for agentless tasks. Learn more

Why does the task failed within 1 minute when the timeout is longer?

If the function executes for more than 1 minute, use the Callback completion event. The API Response completion option is supported for requests that complete within 60 seconds.