Rancher Requirements

RKE

high-availability RKE cluster

• Three Linux nodes, typically virtual machines, in an infrastructure provider such as Amazon’s EC2, Google Compute Engine, or vSphere.

These nodes must be in the same region/data center. You may place these servers in separate availability zones.

Rancher server data is stored on etcd database that runs on all three nodes.

• etcd is a distributed reliable key-value store for the most critical data of a distributed system, with a focus: Simple, Secure, Fast & Reliable.

etcd database requires an odd number of nodes so that it can always elect a leader with a majority of the etcd cluster.

general installation requirements for OS, container runtime, hardware, and networking.

Deployment Size	Clusters	Nodes	vCPUs	RAM
Small	Up to 150	Up to 1500	2	8 GB
Medium	Up to 300	Up to 3000	4	16 GB
Large	Up to 500	Up to 5000	8	32 GB
X-Large	Up to 1000	Up to 10,000	16	64 GB
XX-Large	Up to 2000	Up to 20,000	32	128 GB

Contact Rancher for more than 2000 clusters and/or 20,000 nodes.

• A load balancer to direct front-end traffic to the three nodes.

RKE tool will deploy an NGINX Ingress controller.

This controller will listen on ports 80 and 443 of the worker nodes, answering traffic destined for specific hostnames.

• A layer-4 load balancer

Install NGINX, stream module is required.

nginx.conf

worker_processes 4;
worker_rlimit_nofile 40000;

events {
    worker_connections 8192;
}

stream {
    upstream rancher_servers_http {
        least_conn;
        server <IP_NODE_1>:80 max_fails=3 fail_timeout=5s;
        server <IP_NODE_2>:80 max_fails=3 fail_timeout=5s;
        server <IP_NODE_3>:80 max_fails=3 fail_timeout=5s;
    }
    server {
        listen 80;
        proxy_pass rancher_servers_http;
    }

    upstream rancher_servers_https {
        least_conn;
        server <IP_NODE_1>:443 max_fails=3 fail_timeout=5s;
        server <IP_NODE_2>:443 max_fails=3 fail_timeout=5s;
        server <IP_NODE_3>:443 max_fails=3 fail_timeout=5s;
    }
    server {
        listen     443;
        proxy_pass rancher_servers_https;
    }

}

• A layer-7 load balancer

• A DNS record to map a URL to the load balancer. This will become the Rancher server URL, and downstream Kubernetes clusters will need to reach it.