OpenShift 4.0 libvirt on GCP

Create an OpenShift 4.X cluster in a single GCP instance.

Prerequisites

Images are built and maintained in openshift-gce-devel GCE project. If you are an OpenShift developer and have access to openshift-gce-devel GCE project, all you need to get started is the gcloud CLI tool

For developers not in OpenShift organization, see the centos8-okd4 branch.
For information on images, see IMAGES.md.

Create GCP instance

Note: This script uses scp to copy pull-secret to gcp instance.  Alternative is to
add pull-secret to metadata when creating the instance.  However, metadata is printed
in the gcp console.  This is why this setup uses scp instead. 

You'll need a network and firewall rules to connect to your instance. This is already set up for developers in openshift-gce-devel, it's ocp4-libvirt-dev. The script create-gcp-instance.sh will launch an instance using this network. If you prefer, you can run create-network-subnet.sh and then the commands from the create-gcp-instance.sh to create an instance in a different network. To use the preconfigured network ocp4-libvirt-dev, run the script like so:

$ export INSTANCE=mytest
$ export GCP_USER=<whatever name you login as to gcp instance>, used to scp pull-secret to $HOME/pull-secret in gcp instance
$ export PULL_SECRET=/path/to/pull-secret-one-liner.json
$ ./create-gcp-instance.sh

Find an available release payload image

You need to provide a release payload that you have access to. This setup will extract the installer binary from the RELEASE_IMAGE you provide. For public images see ocp-dev-preview and quay.io/ocp-dev-preview or for internal images see CI release images

Create nested libvirt cluster - 3 masters, 2 workers

Connect to the instance using SSH and create a cluster named $CLUSTER_NAME using latest payload built from CI. Install directory will be populated at $HOME/clusters/$CLUSTER_NAME.

$ gcloud beta compute ssh --zone "us-east1-c" $INSTANCE --project "openshift-gce-devel"
$ RELEASE_IMAGE=registry.svc.ci.openshift.org/ocp/release:whatever create-cluster $CLUSTER_NAME

Tear Down Cluster

You can tear down and relaunch easily within your gcp instance like so:

$ gcloud beta compute ssh --zone "us-east1-c" $INSTANCE --project "openshift-gce-devel"
$ openshift-install destroy cluster --dir ~/clusters/$ClUSTER_NAME && rm -rf ~/clusters/$CLUSTER_NAME

Tear Down and Clean Up GCP.

Clean up your GCP instance when you are done with your development cluster. To delete the instance:

$ gcloud compute instances delete INSTANCE_NAME

Interact with your cluster with oc while connected via ssh to your gcp instance.

Updating the installer

Tools can be updated right from the instance itself.

Update the OpenShift installer from https://github.com/openshift/installer.git master using:

$ gcloud beta compute ssh --zone "us-east1-c" $INSTANCE --project "openshift-gce-devel"
$ update-installer

Update the OpenShift installer from https://github.com/repo-owner/installer.git branch using:

$ gcloud beta compute ssh --zone "us-east1-c" $INSTANCE --project "openshift-gce-devel"
$ update-installer repo-owner branch

Advanced usage

It's possible to ignore all the defaults and helpers and simply use the image as a stable base for libvirt installer development. You can use openshift-install binary without the create-cluster if you prefer.