In the release pipeline, you can use the Invoke REST API task to call the REST API “Runs – Run Pipeline” to trigger a YAML pipeline or classic build pipeline.

1. Go to Project Settings > Service connections to create a Generic service connection.

   • Server URL: The prefix of the REST API URI. You can set it as “https://dev.azure.com/{organization}“. Replace {organization} with the actual name of your Azure DevOps organization.

   • Service connection name: Enter a custom name of the service connection.

2. Go the release pipeline, add the following things.

   • Add an Agentless job. You can set condition on this job so that the job can run only when the condition is met.

   • Add an Invoke REST API task in the Agentless job.

3. On the Invoke REST API task, set the following configurations.

   • Display name: You can set a custom name of the step.

   • Connection type: Generic

   • Generic service connection: The name of the Generic service connection created previously.

   • Method: POST

   • Headers: A JSON content to set the request headers of the API call.

     {
     "Content-Type":"application/json", 
     "Authorization": "Bearer $(system.AccessToken)"
     }
     

   • Body: A JSON content to set the Request Body of the API call. For example.

     // Overwrite the default values of a parameter and a pipeline variable when triggering the pipeline.
     
     {
         "variables": {
             "myVar02": {
                 "value": "4444"
             }
         },
         "templateParameters": {
             "myPara01": "1111"
         }
     }
     

   • URL suffix and parameters: The suffix of the REST API URI. It will combine with the prefix set in the service connection to get the full REST API URI. You can set it as “/{project}/_apis/pipelines/{pipelineId}/runs?api-version=7.0“. Replace {project} and {pipelineId} with you actual values.

With this method, you do not need an agent jobs to trigger the pipeline. So, do not need to wait an available agent in your Azure DevOps organization. The Agentless job can run more quickly than the agent job.

Few options:

• Install a free marketplace extension Trigger Azure DevOps Pipeline

• Add a script task and use the Azure DevOps REST API to trigger your pipeline.

Just a suggestion, not sure if they need to be seperate as I am more leaning towards using yaml templates for everything (combining both your CI and CD into a single yaml can be done).

As well as bryanbcook said, there are third party marketplace extensions that do that.

You can also use REST calls from Azure DevOps and write a small powershell script (or any language) to create a release. I believe this may be the call (assuming Azure DevOps Services) to create a new release.

https://learn.microsoft.com/en-us/rest/api/azure/devops/release/releases/create?view=azure-devops-rest-7.1&tabs=HTTP