Nginx Loadbalancer for Rancher Kubernetes

Use Terraform to deploy a Nginx Loadbalancer for a Rancher Kubernetes Cluster.

Summary

This is not a Kubernetes Ingress. This project's goal is to provide an alternative to a hardware loadbalancer such as an F5 for load balancing Kubernetes worker nodes. More specifically this project allows you to host a public Kubernetes cluster behind a NAT boundary using server names and SSL SNI. The current Nginx configuration has been customized for running a three node Rancher Kubernetes cluster however it can be modified to load balance any Kubernetes Cluster.

Note: This project is customized for KVM servers running Openvswitch. Installation of these dependencies can be complex and is outside the scope of this project.

Prereqs

KVM Server running Openvswitch

• https://github.com/mrlesmithjr/ansible-kvm
• https://docs.openvswitch.org/en/latest/intro/install/distributions/

Terraform and the terraform-provider-libvirt

• https://www.terraform.io/downloads.html
• https://github.com/dmacvicar/terraform-provider-libvirt#installing

Setup

Clone Repository

git clone https://github.com/2stacks/terraform-nginx-lb.git
cd terraform-nginx-lb

Create secrets variable file, add your SSH public key and update database passwords.

cp secret.auto.tfvars.example secret.auto.tfvars

Deploy libvirt guest with Terraform

terraform init
terraform plan
terraform apply

When Terraform finishes it will output the libvirt guest IP

Example:

Outputs:

ip = [
    [
        192.168.100.15,
        fe80::5054:ff:fec2:43bd
    ]
]

If running this load balancer behind a NAT boundary you should set up port forwarding for TCP 80 and 443 to the IP given in the Terraform Output.

Important Variables

Variable Name	Usage
domain_name	Sets the domian name of the Rancher server and Kubernetes worker nodes to be loadbalanced
nameserver	Name server the loadbalancer should use to resolve the Rancher server and node names

TODO

• Use jinja2 to produce the nginx.conf