OpenShift Node Operations
External
Internal
Overview
A node is a Linux container host. More details about nodes are available here:
Getting Information about a Node
oc get nodes oc get node <node-name> oc describe node/<node-name>
Starting/Stopping a Node
Get Labels Applied to a Node
Update Labels on a Node
Other Procedures
Adding a New Node
New nodes can be added with the scaleup.yml playbook. The playbook generates and distributes new certificates for the new hosts, then runs the configuration playbook on the new hosts only. However, before running the playbook, the host must be prepared in the same way the other nodes were. If the nodes were created based on a template, the same template should be used to stand up the new node. For more details, see:
Use the same Ansible inventory file that was used to install the rest of the cluster.
On the Ansible host, update to the latest version of 'atomic-openshift-utils'
yum update atomic-openshift-utils
In the Ansible inventory file, add "new_<host_type> to the [OSEv3:children] section:
[OSEv3:children] masters etcd nodes new_nodes lb nfs
Create a [new_<host_type>] section following the patterns already in place for the similar types of nodes:
[new_nodes]
node3.local openshift_node_labels="{'logging':'true', 'cluster':'noper430', 'env':'lab'}"
Execute the playbook:
cd /etc/ansible ansible-playbook /usr/share/ansible/openshift-ansible/playbooks/byo/openshift-node/scaleup.yml
After the installation of the new nodes completes, move any hosts that have been defined in the [new_<host_type>] section into their appropriate section (but leave the [new_<host_type>] section definition itself in place, albeit empty) so that subsequent runs using this inventory file are aware of the nodes but do not handle them as new nodes.
[nodes]
...
node1.local openshift_node_labels="{'logging':'true', 'cluster':'noper430', 'env':'app'}"
node2.local openshift_node_labels="{'logging':'true', 'cluster':'noper430', 'env':'app'}"
node3.local openshift_node_labels="{'logging':'true', 'cluster':'noper430', 'env':'lab'}"
[new_nodes]
Removing a Node
TODO: https://docs.openshift.com/container-platform/3.5/admin_guide/manage_nodes.html#deleting-nodes