Rancher Requirements

Large Clusters

• A cluster is a set of nodes (physical or virtual machines) running Kubernetes agents, managed by the control plane.
  • No more than 100 pods per node
  • No more than 5,000 nodes
  • No more than 150,000 total pods
  • No more than 300,000 total containers
• Consider resource quotas
  • Computer instances
  • CPUs
  • Storage volumes
  • In-use IP addresses
  • Packet filtering rule sets
  • Number of load balancers
  • Network subnets
  • Log streams
• need a control plane with sufficient compute and other resources.
• store Event objects in a separate dedicated etcd instance

need a control plane with sufficient compute and other resources.

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.

/etc/nginx/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;
    }

}

docker run -d --restart=unless-stopped \
  -p 80:80 -p 443:443 \
  -v /etc/nginx.conf:/etc/nginx/nginx.conf \
  nginx:1.14

• 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.

RancherD

Deployment Size	Clusters	Nodes	vCPUs	RAM
Small	Up to 5	Up to 50	2	5 GB
Medium	Up to 15	Up to 200	3	9 GB

Worker

Linux

• Requirements
  • 1 core CPU
  • 1 GB memory
• Install the Required CLI Tools

kubectl - Kubernetes command-line tool.

helm - Package management for Kubernetes.

• Add the Helm Chart Repository

helm repo add rancher-stable https://releases.rancher.com/server-charts/stable

• Create a Namespace for Rancher

kubectl create namespace cattle-system

• Choose your SSL Configuration

Configuraton	Helm Chart Option	Requires cert-manager
Rancher Generated Certificates (Default)	ingress.tls.source=rancher	yes
Let’s Encrypt	ingress.tls.source=letsEncrypt	yes
Certificates from Files	ingress.tls.source=secret	no

• Install cert-manager (if requires)

# Install the CustomResourceDefinition resources separately
kubectl apply --validate=false -f https://github.com/jetstack/cert-manager/releases/download/v1.0.4/cert-manager.crds.yaml

# **Important:**
# If you are running Kubernetes v1.15 or below, you
# will need to add the `--validate=false` flag to your
# kubectl apply command, or else you will receive a
# validation error relating to the
# x-kubernetes-preserve-unknown-fields field in
# cert-manager’s CustomResourceDefinition resources.
# This is a benign error and occurs due to the way kubectl
# performs resource validation.

# Create the namespace for cert-manager
kubectl create namespace cert-manager

# Add the Jetstack Helm repository
helm repo add jetstack https://charts.jetstack.io

# Update your local Helm chart repository cache
helm repo update

# Install the cert-manager Helm chart
helm install \
  cert-manager jetstack/cert-manager \
  --namespace cert-manager \
  --version v1.0.4

kubectl get pods --namespace cert-manager

NAME                                       READY   STATUS    RESTARTS   AGE
cert-manager-5c6866597-zw7kh               1/1     Running   0          2m
cert-manager-cainjector-577f6d9fd7-tr77l   1/1     Running   0          2m
cert-manager-webhook-787858fcdb-nlzsq      1/1     Running   0          2m

• Install Rancher with Helm and Your Chosen Certificate Option

Rancher Generated Certificates (Default)

helm install rancher rancher-latest/rancher \
  --namespace cattle-system \
  --set hostname=rancher.my.org

kubectl -n cattle-system rollout status deploy/rancher
Waiting for deployment "rancher" rollout to finish: 0 of 3 updated replicas are available...
deployment "rancher" successfully rolled out

• HTTP Proxy
• Private Docker Image Registry
• TLS Termination on an External Load Balancer

• Verify that the Rancher Server is Successfully Deployed

kubectl -n cattle-system rollout status deploy/rancher
Waiting for deployment "rancher" rollout to finish: 0 of 3 updated replicas are available...
deployment "rancher" successfully rolled out

kubectl -n cattle-system get deploy rancher
NAME      DESIRED   CURRENT   UP-TO-DATE   AVAILABLE   AGE
rancher   3         3         3            3           3m

• Save Your Options

Make sure you save the --set options you used.

• Finishing Up
• Optional Next Steps

Enable the Enterprise Cluster Manager.

Windows

• Docker Engine - Enterprise Edition (EE)
• Requirements
  • 2 core CPUs
  • 5 GB memory
  • 50 GB disk space
• Rancher only supports Windows using Flannel as the network provider.

2 network options: Host Gateway (L2bridge) and VXLAN (Overlay)(default)

• Host Gateway (L2bridge):

best to use the same Layer 2 network for all nodes. Otherwise, you need to configure the route rules for them.

maybe need to disable private IP address checks

• VXLAN (Overlay):

KB4489899 hotfix must be installed

• Minimum Architecture Requirements

Operating System	Kubernetes Cluster Role	Purpose
Linux	Control plane, etcd, worker	Manage the Kubernetes cluster
Linux	Worker	Support the Rancher Cluster agent, Metrics server, DNS, and Ingress for the cluster
Windows Server core 1809 or above	Worker	Run your Windows containers