Create Tekton on OKD Document

[JaimeMagiera]

Create a document that outlines a basic install of Tekton pipelines on OKD.

[GeoEducator]

I have joined tekton documentation groups, etc and such info, working on understanding

[bdlink]

After trying many ways to get Tekton operator and all, this worked for me:
Building on MacOS did not work.
Using latest go version 1.18 did not work, had to go to 1.17 (think this is no longer needed)

Built on Fedora using https://github.com/tektoncd/operator/blob/main/DEVELOPMENT.md
Steps:
Update your (external) dependencies with: ./hack/update-deps.sh
Update your type definitions with: ./hack/update-codegen.sh
Add openshift scripts with ./hack/openshift/fetch-tektoncd-catalog-tasks.sh cmd/openshift/operator/kodata/tekton-addon/addons/02-clustertasks/source_external
Update again with ./hack/update-codegen.sh
Make sure cluster is clean:
make TARGET=openshift clean
Define where container repo is Set KO_DOCKER_ENV environment variable (ko#usage) here quay.io
Apply operator: make TARGET=openshift apply
Make sure containers in repo are public or define pull secret to get them
Install all pipeline components with make TARGET=openshift CR=config/all apply-cr

will take ~ half hour to populate openshift-pipelines

Does not seem needed to apply SCC this way (perhaps needed for some tasks?)

Do not try the end to end tests on a production server, for me it cleaned out all operators (not just Tekton ones)

Trying various ways of installing Tekton, many unsuccessful attempts left residual tektoninstallersets in etcd that needed to be cleaned out to proceed:

/kubernetes.io/operator.tekton.dev/tektoninstallersets/addon-communityclustertasks-7wjf5
/kubernetes.io/operator.tekton.dev/tektoninstallersets/addon-triggers-9zpf8
/kubernetes.io/operator.tekton.dev/tektoninstallersets/addon-versioned-clustertasks-devel-qv4fg
/kubernetes.io/operator.tekton.dev/tektoninstallersets/pipeline-vnhnn
/kubernetes.io/operator.tekton.dev/tektoninstallersets/prepipeline-vx6vf
/kubernetes.io/operator.tekton.dev/tektoninstallersets/trigger-d9h4w
/kubernetes.io/operator.tekton.dev/tektoninstallersets/validating-mutating-webhoook-6q28h

(find with etcdctl get --keys-only --from-key / | grep tekton
remove with etcdctl del …)

[GeoEducator]

excellent, whew...
how much space did it take on Fedora, 36?

[bdlink]

To upgrade to 4.12 needed to uninstall old Tekton CD operator. The openshift-pipelines-operator is using the v2beta1/horizontalpodautoscalers api. This disappears in k8s 1.25