# yum update atomic-openshift-utils
Depending on how your OpenShift Origin cluster was installed, you can add new hosts (either nodes or masters) to your installation by using the install tool for quick installations, or by using the scaleup.yml playbook for advanced installations.
If you used the quick install tool to install your OpenShift Origin cluster, you can use the quick install tool to add a new node host to your existing cluster.
|
Currently, you can not use the quick installer tool to add new master hosts. You must use the advanced installation method to do so. |
If you used the installer in either
interactive or
unattended mode, you can re-run the
installation as long as you have an
installation configuration
file at ~/.config/openshift/installer.cfg.yml (or specify a different
location with the -c option).
|
The recommended maximum number of nodes is 300. |
To add nodes to your installation:
Ensure you have the latest installer and playbooks by updating the atomic-openshift-utils package:
# yum update atomic-openshift-utils
Run the installer with the scaleup subcommand in interactive or
unattended mode:
# atomic-openshift-installer [-u] [-c </path/to/file>] scaleup
The installer detects your current environment and allows you to add additional nodes:
*** Installation Summary *** Hosts: - 100.100.1.1 - OpenShift master - OpenShift node - Etcd (Embedded) - Storage Total OpenShift masters: 1 Total OpenShift nodes: 1 --- We have detected this previously installed OpenShift environment. This tool will guide you through the process of adding additional nodes to your cluster. Are you ready to continue? [y/N]:
Choose (y) and follow the on-screen instructions to complete your desired task.
If you installed using the advanced install, you can add new hosts to your cluster by running the scaleup.yml playbook. This playbook queries the master, generates and distributes new certificates for the new hosts, then runs the configuration playbooks on the new hosts only. Before running the scaleup.yml playbook, complete all prerequisite host preparation steps.
You must have an existing inventory file (for example, /etc/ansible/hosts) that is representative of your current cluster configuration in order to run the scaleup.yml playbook.
|
The recommended maximum number of nodes is 300. |
To add a host to an existing cluster:
Ensure you have the latest playbooks by updating the atomic-openshift-utils package:
# yum update atomic-openshift-utils
Edit your /etc/ansible/hosts file and add new_<host_type> to the [OSEv3:children] section:
For example, to add a new node host, add new_nodes:
[OSEv3:children] masters nodes new_nodes
To add new master hosts, add new_masters.
Create a [new_<host_type>] section much like an existing section, specifying host information for any new hosts you want to add. For example, when adding a new node:
[nodes]
master[1:3].example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
[new_nodes]
node3.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
See Configuring Host Variables for more options.
When adding new masters, hosts added to the [new_masters] section must also be
added to the [new_nodes] section with the openshift_schedulable=false
variable. This ensures the new master host is part of the OpenShift SDN and that
pods are not scheduled for placement on them. For example:
[masters]
master[1:2].example.com
[new_masters]
master3.example.com
[nodes]
node[1:3].example.com openshift_node_labels="{'region': 'infra'}"
master[1:2].example.com openshift_schedulable=false
[new_nodes]
master3.example.com openshift_schedulable=false
Run the scaleup.yml playbook. If your inventory file is located somewhere
other than the default of /etc/ansible/hosts, specify the location with the
-i option.
For additional nodes:
# ansible-playbook [-i /path/to/file] \
/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-node/scaleup.yml
For additional masters:
# ansible-playbook [-i /path/to/file] \
/usr/share/ansible/openshift-ansible/playbooks/byo/openshift-master/scaleup.yml
After the playbook completes successfully, verify the installation.
Finally, move any hosts you had defined in the [new_<host_type>] section into their appropriate section (but leave the [new_<host_type>] section definition itself in place) so that subsequent runs using this inventory file are aware of the nodes but do not handle them as new nodes. For example, when adding new nodes:
[nodes]
master[1:3].example.com openshift_node_labels="{'region': 'infra', 'zone': 'default'}"
node1.example.com openshift_node_labels="{'region': 'primary', 'zone': 'east'}"
node2.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
node3.example.com openshift_node_labels="{'region': 'primary', 'zone': 'west'}"
[new_nodes]