Your cluster is now ready to use, but you should get an error message if you run the tkn version command. This error is due to the fact that by deleting everything in your cluster, you also deleted all the CRDs necessary for Tekton.

For this reason, you need to reinstall Tekton, Tekton Triggers, and make some adjustments to your cluster to ensure that you will be able to run those tools.

First, start by installing Tekton by applying the appropriate file to your cluster with kubectl:

 $ kubectl apply --filename https://storage.googleapis.com/tekton-releases/pipeline/latest/release.yaml 

Next, install the necessary CRDs for Tekton Triggers using kubectl:

$ kubectl apply -f https://storage.googleapis.com/tekton-releases/triggers/latest/release.yaml 
$ kubectl apply -f https://storage.googleapis.com/tekton-releases/triggers/latest/interceptors.yaml 

To build your triggers, you will need to create a service account, just like you did...