HACKING: update bringup notes to account for fedora-coreos-pipeline changes

The pipeline was updated to change the structure of the jenkins images
dependency chain in [1] so we needed to update the notes here.

[1] coreos/fedora-coreos-pipeline#1151

Author: dustymabe

HACKING.md

@@ -5,14 +5,10 @@ First, create the Jenkins base infra:
 ```
 oc process -l app=coreos-ci \
     -p ENABLE_OAUTH=false \
-    -p NAMESPACE=coreos-ci \
     -p STORAGE_CLASS_NAME=ocs-storagecluster-ceph-rbd \
     -f https://raw.githubusercontent.com/coreos/fedora-coreos-pipeline/main/manifests/jenkins.yaml | oc create -f -
 ```
 
-Change the `NAMESPACE` parameter if you're not targeting one
-named `coreos-ci`.
-
 We turn off the default OpenShift authentication because we
 will use GitHub instead.
 
@@ -122,13 +118,38 @@ If working on your own fork/branch, you can point the
 `JENKINS_JOBS_URL` and `JENKINS_JOBS_REF` parameters to
 override the repo in which to look for jobs.
 
+### Create Dummy root CA certificate secret
+
+The root CA certificate (ca.crt) is required, but not needed for CoreOS CI
+so we create a dummy one here.
+
+```
+cat <<'EOF' > ca.crt
+dummy
+EOF
+```
+Then create the secret:
+
+```
+oc create secret generic additional-root-ca-cert \
+    --from-literal=filename=ca.crt --from-file=data=ca.crt
+oc label secret/additional-root-ca-cert \
+    jenkins.io/credentials-type=secretFile
+oc annotate secret/additional-root-ca-cert \
+    jenkins.io/credentials-description="Dummy Root CA certificate"
+```
+
 ### Jenkins
 
 Now we can set up the Jenkins S2I builds. We use the same
 settings as the FCOS pipeline to ensure that the environment
 is the same (notably, Jenkins and plugin versions):
 
 ```
+oc process -l app=coreos-ci \
+    -f https://raw.githubusercontent.com/coreos/fedora-coreos-pipeline/main/manifests/jenkins-images.yaml | oc create -f -
+oc process -l app=coreos-ci \
+    -f https://raw.githubusercontent.com/coreos/fedora-coreos-pipeline/main/manifests/jenkins-with-cert.yaml | oc create -f -
 oc process -l app=coreos-ci \
     -f https://raw.githubusercontent.com/coreos/fedora-coreos-pipeline/main/manifests/jenkins-s2i.yaml | oc create -f -
 ```
@@ -138,10 +159,12 @@ If working on your own fork/branch, you can point the
 override the repo in which to look for the Jenkins S2I
 configuration.
 
-Then start a build:
+Then start the builds:
 
 ```
-oc start-build jenkins-s2i
+oc start-build --follow jenkins-with-cert
+oc start-build --follow jenkins-agent-base-with-cert
+oc start-build --follow jenkins-s2i
 ```
 
 And that's it! It's already set up so that jobs will be