title: Azure Pipeline to trigger Pipeline using YAML
body: <p>Attempting to trigger an Azure pipeline when another pipeline has been completed using a YAML. There's <a href="https://github.com/microsoft/azure-pipelines-yaml/blob/master/design/pipeline-resources.md" rel="noreferrer">documentation</a> indicating that you can add a pipeline resource with:</p>
  
  <pre><code>resources:   # types: pipelines | builds | repositories | containers | packages
    pipelines:
    - pipeline: string  # identifier for the pipeline resource
      connection: string  # service connection for pipelines from other Azure DevOps organizations
      project: string # project for the source; optional for current project
      source: string  # source defintion of the pipeline
      version: string  # the pipeline run number to pick the artifact, defaults to Latest pipeline successful across all stages
      branch: string  # branch to pick the artiafct, optional; defaults to master branch
      tags: string # picks the artifacts on from the pipeline with given tag, optional; defaults to no tags
  </code></pre>
  
  <p>However, I've been unable to figure out what the "source" means. For example, I have a pipeline called <code>myproject.myprogram</code>:</p>
  
  <pre><code>resources:
    pipelines:
    - pipeline: myproject.myprogram
      source: XXXXXXXX
  </code></pre>
  
  <p>Moreover, it's unclear how you'd build based a trigger based on this.</p>
  
  <p>I know that this can be done from the web-GUI, but it should be possible to do this from a YAML.</p>