Installing SUSE® Rancher Prime in a VMware vSphere Environment
This guide outlines a reference architecture for installing Rancher on an RKE Kubernetes cluster in a VMware vSphere environment. It also desctibes standard vSphere best practices as documented by VMware.
1. Load Balancer Considerations
A load balancer is required to direct traffic to the Rancher workloads residing on the RKE nodes.
Leverage Fault Tolerance and High Availability
Leverage the use of an external (hardware or software) load balancer that has inherit high-availability functionality (F5, NSX-T, Keepalived, etc).
Back Up Load Balancer Configuration
In the event of a Disaster Recovery activity, availability of the Load balancer configuration will expedite the recovery process.
Configure Health Checks
Configure the Load balancer to automatically mark nodes as unavailable if a health check is failed. For example, NGINX can facilitate this with:
max_fails=3 fail_timeout=5s
2. VM Considerations
Leverage VM Templates to Construct the Environment
To facilitate the consistency of Virtual Machines deployed across the environment, consider the use of "Golden Images" in the form of VM templates. Packer can be used to accomplish this, adding greater customization options.
Leverage DRS Anti-Affinity Rules (Where Possible) to Separate Rancher Cluster Nodes Across ESXi Hosts
Doing so will ensure node VM’s are spread across multiple ESXi hosts - preventing a single point of failure at the host level.
Leverage DRS Anti-Affinity Rules (Where Possible) to Separate Rancher Cluster Nodes Across Datastores
Doing so will ensure node VM’s are spread across multiple datastores - preventing a single point of failure at the datastore level.
Configure VM’s as Appropriate for Kubernetes
It’s important to follow K8s and etcd best practices when deploying your nodes, including disabling swap, double-checking you have full network connectivity between all machines in the cluster, using unique hostnames, MAC addresses, and product_uuids for every node.
3. Network Considerations
Leverage Low Latency, High Bandwidth Connectivity Between ETCD Nodes
Deploy etcd members within a single data center where possible to avoid latency overheads and reduce the likelihood of network partitioning. For most setups, 1Gb connections will suffice. For large clusters, 10Gb connections can reduce the time taken to restore from backup.