Configuring for GCE | Installation and Configuration

Overview

OpenShift Origin can be configured to access a Google Compute Engine (GCE) infrastructure, including using GCE volumes as persistent storage for application data. After GCE is configured properly, some additional configurations will need to be completed on the OpenShift Origin hosts.

Permissions

Configuring Google Cloud Platform (GCP) for OpenShift Origin requires the following role:

roles/owner

To create service accounts, cloud storage, instances, images, templates, Cloud DNS entries, and deploy load balancers and health checks. It is helpful to also have delete permissions to be able to redeploy the environment while testing.

Configuring Masters

You can set the GCE configuration on your OpenShift Origin master hosts in two ways:

Configuring OpenShift Origin Masters for GCE with Ansible

During advanced installations, GCE can be configured using the openshift_cloudprovider_kind parameter, which is configurable in the inventory file.

Example GCE Configuration with Ansible

# Cloud Provider Configuration
#
  openshift_cloudprovider_kind=gce

When Ansible configures GCE, the following files are created for you:

/etc/origin/cloudprovider/gce.conf
/etc/origin/master/master-config.yaml
/etc/origin/node/node-config.yaml

The advanced installation configures multizone support by default. If you want single-zone support, edit the /etc/origin/cloudprovider/gce.conf as shown in Configuring Multizone Support in a GCE Deployment.

Manually Configuring OpenShift Origin Masters for GCE

To configure the OpenShift Origin masters for GCE:

Edit or create the master configuration file (/etc/origin/master/master-config.yaml by default) on all masters and update the contents of the apiServerArguments and controllerArguments sections:

kubernetesMasterConfig:
  ...
  apiServerArguments:
    cloud-provider:
      - "gce"
    cloud-config:
      - "/etc/origin/cloudprovider/gce.conf"
  controllerArguments:
    cloud-provider:
      - "gce"
    cloud-config:
      - "/etc/origin/cloudprovider/gce.conf"

When triggering a containerized installation, only the directories of /etc/origin and /var/lib/origin are mounted to the master and node container. Therefore, master-config.yaml should be in /etc/origin/master instead of /etc/.

Start or restart the OpenShift Origin services:

# systemctl restart origin-master-api origin-master-controllers

Configuring Nodes

To configure the OpenShift Origin nodes for GCE:

Edit or create the node configuration file (/etc/origin/node/node-config.yaml by default) on all nodes and update the contents of the kubeletArguments section:
kubeletArguments: cloud-provider: - "gce" cloud-config: - "/etc/origin/cloudprovider/gce.conf"

Currently, the nodeName must match the instance name in GCE in order for the cloud provider integration to work properly. The name must also be RFC1123 compliant.

When triggering a containerized installation, only the directories of /etc/origin and /var/lib/origin are mounted to the master and node container. Therefore, node-config.yaml should be in /etc/origin/node instead of /etc/.

Start or restart the OpenShift Origin services all nodes.
```
# systemctl restart origin-node
```

Configuring Multizone Support in a GCE Deployment

If manually congifuring GCE, multizone support is not configured by default.

The advanced installation configures multizone support by default.

If you want multizone support:

Edit or create a /etc/origin/cloudprovider/gce.conf file on all of your OpenShift Origin hosts, both masters and nodes.
Add the following contents:
```
[Global]
multizone = true
```

To return to single-zone support, set the multizone value to false.

Applying Configuration Changes

Start or restart OpenShift Origin services on all master and node hosts to apply your configuration changes, see Restarting OpenShift Origin services:

# systemctl restart origin-master-api origin-master-controllers
# systemctl restart origin-node

Switching from not using a cloud provider to using a cloud provider produces an error message. Adding the cloud provider tries to delete the node because the node switches from using the hostname as the externalID (which would have been the case when no cloud provider was being used) to using the AWS instance-id (which is what the AWS cloud provider specifies). To resolve this issue:

Check and back up existing node labels:

$ oc describe node <node_name> | grep -Poz '(?s)Labels.*\n.*(?=Taints)'

Delete the nodes:
```
$ oc delete node <node_name>
```
On each node host, restart the OpenShift Origin service.
```
# systemctl restart origin-node
```
Add back any labels on each node that you previously had.