title: How to set up a generic webhook trigger in Tekton
body: <p>I want to set up a webhook trigger in tekton. <a href="https://github.com/tektoncd/triggers" rel="nofollow noreferrer">In the documentation</a>, I can find Github, Gitlab and bitbucket triggers available. But I want a generic webhook that processes HTTP POST and reads the JSON body.</p>
  <p>For example: I am doing the following with Jenkins' generic webhook trigger.</p>
  <p>Prometheus Alertmanager sends a HTTP POST to Jenkins' Generic webhook and Jenkins processes the JSON body and kicks off the build.</p>
  <p>I want to the same with Tekton. Alertmanager sends a HTTP POST to the Tekton webhook and it would process the JSON body and kick off the build.</p>
  <p>Is this doable with Tekton's webhook trigger? Is this not available yet in tekton or am i missing something form the <a href="https://github.com/tektoncd/triggers" rel="nofollow noreferrer">documentation</a>?</p>
  <p>If someone has already done this, can you point me in the right direction? I am using openshift 4.5</p>