OpenShift Origin : Multiple Masters installation

Question

I'm a bit new with OpenShift, i've already made a install for a master and multiple nodes ( this setup is deleted now ).

Now i need more reliability, so i'm currently preparing my hosts with three masters and two nodes ( for starting ).

I've a dns, a dhcp and an etcd2 cluster up and running with the specifics entries for the hosts like :

• openshift-router ( external and internal access this will be use as LB with HAproxy )
• openshift-etcd1
• openshift-etcd2
• openshift-etcd2
• openshift-master1
• openshift-master2
• openshift-master3
• openshift-node1
• openshift-node2

But now i have three questions :

• Where do i run my ansible playbook from the router or on one of the masters ?
• Do i need to create a shared pool for the docker-storage or just create a new disk on each master ?
• Have you already experienced issues with the multi master configuration ?

i know, i ask many questions, but thoses questions are in the same subject, how to make a HA setup with OpenShift.

Thanks you in advance.

Answer 1

I am able to answer only 2 of your questions.

1. It does not matter from which host you run the Ansible playbook. You can also run it from a host which is not part of the whole openshift setup (e.g. your laptop) Note: If you change a host's role (from master to node or vice versa), be sure to delete the Ansible facts before running the config playbook again. Otherwise the changes won't be picked up

2. Follow up: are you asking about the shared pool in reference to High Availability of the Masters ?

3. Multi master setup provisioned using the Ansible playbook works as expected. The state of the masters is synced using etcd

Some minor issues faced:

• There was a small hiccup w.r.t. origin-node service not finding docker's PID. Workaround: https://github.com/kubernetes/kubernetes/issues/26259#issuecomment-229303274
• openvswitch fails to set up networking correctly. Workaround: restart openvswitch service