Trigger Azure Devops build pipelines using REST API

In some cases you may need to schedule pipelines execution on nights but the schedules yaml feature cannot accomplish your needs. This could could happen if you have to provide parameters as inputs on the pipelines for a specific project export/import. In this case you could trigger your pipelines with REST APIs using ansible or another scripting tool.

In this article I will explain how you could trigger pipelines execution using the REST API of Azure Devops.

First things first you should create a personal access Token (PAT) in order to get the access required to run the pipelines on your organization. You can accomplish that by pressing your profile icon and selecting the sub-menu shown below.

You can specify the expiration of the token along with the access permissions. For the simplicity of deployment I gave it full access. You will need to copy the token somewhere as it will not be accessible after the creation.

In order to trigger a new build we would have to use the POST HTTP verb. Along with that we will need the repository name, the project name and the build pipeline ID. The below URL uses build API of version 6.1-preview.6 with the parameters

Organization: GeralexGR
Project: test-project

https://dev.azure.com/GeralexGR/test-project/_apis/build/builds?api-version=6.1-preview.6

Using CURL we can get information of runs for a specific pipeline. For example in order to get the latest runs for pipeline with ID:11. In the below example you should replace PAT with your provisioned personal access token.

curl  --user '':'PAT' --header "Content-Type: application/json" --header "Accept:application/json" https://dev.azure.com/GeralexGR/test-project/_apis/pipelines/11/runs?api-version=6.1-preview.1

In order to implement a run of a build pipeline using REST APIs I will use Postman.

The selected verb is POST and the URL is the one mentioned above. By giving the URL on the input field, POSTMAN will automatically enumerate Query parameters.

In Authorization tab you should select Basic Auth. The username can be empty and the password will be your PAT.

On Headers tab, add Content-Type as application/json

In the body, you should specify the build pipeline ID in the JSON format that is shown in the picture. If you press Send, you will successful trigger your build pipeline with ID 11.

The next step is to edit the pipeline to include also input parameters.

In order to do that, I will use the latest version of the REST API that uses the runs URL instead of builds.

As shown in the picture the request URL will be pipelines/buildID/runs

https://dev.azure.com/GeralexGR/test-project/_apis/pipelines/11/runs?&api-version=6.1-preview.1

The logic of the pipeline will only print the parameters that has been provided as input on the REST API.

trigger:
- none

pr: none 

pool:
  vmImage: ubuntu-latest

parameters:
  - name: name
    displayName: Tell me your name.
    type: string
    
steps:
- script: echo ${{parameters.name}} "succesfully triggered this build from a REST API call"
  displayName: 'print message from automatically created pipeline'

You can see in the result that my name is printed.

Azure Devops Rest API documentation:

https://docs.microsoft.com/en-us/rest/api/azure/devops/pipelines/runs/run-pipeline?view=azure-devops-rest-6.0

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