High Availability Single Node Openshift Setup Operator
Provide the ability for exactly two Single Node OpenShift clusters to operate as a predefined pair in an active-passive or active-active configuration, detect when its peer has died and automatically take over its workloads after ensuring it is safe to do so.
Motivation
Some companies have a need for a highly available container management solution that fits within a reduced footprint.
- The hardware savings are significant for customers deploying many remote sites (kiosks, branch offices, restaurant chains, etc), most notably for edge computing and RAN specifically.
- The physical constraints of some deployments prevent more than two nodes (planes, submarines, satellites, and also RAN).
- Some locations will not have reliable network connections or limited bandwidth (once again submarines, satellites, and disaster areas such as after hurricanes or floods)
Pre-requisites
- 2 SNO Clusters.
- Deployments that will be managed by HA Layer already exist.
Installation
- Deploy This operator to each SNO cluster.
- Load the yaml manifest of the HASNO (for each SNO cluster).
Assumptions
- CRs will be updated simultaneously on both clusters by a config management tool - for example ACM (in case no such tool is used it should be done manually by the user).
Example CRs
An example HASNO object.
apiVersion: app.hasno.com/v1alpha1
kind: HALayerSet
metadata:
name: halayerset-sample
spec:
# Add fields here
deployments:
- "nginx-test"
- "nginx-prod"
fenceAgentsSpec:
- name: "fence_ipmilan_1"
type: "fence_ipmilan"
params:
ip: "192.168.126.1"
username: "admin"
password: "password"
ipport: "9111"
lanplus: "1"
pcmk_host_list: "cluster1"
- name: "fence_ipmilan_2"
type: "fence_ipmilan"
params:
ip: "192.168.126.1"
username: "admin"
password: "password"
ipport: "9222"
lanplus: "1"
pcmk_host_list: "cluster2"
nodesSpec:
firstNodeName: "cluster1"
firstNodeIP: "192.168.126.10"
secondNodeName: "cluster2"
secondNodeIP: "192.168.126.11"
These CRs are created by the admin and are used to trigger the setting of the High Availability Layer on top of the SNO clusters.
