multi cluster multi cloud setup

Signed-off-by: Joshua Fernandes <joshua.fernandes@consensys.net>

docs/private-networks/tutorials/kubernetes/multi-cluster.md

@@ -0,0 +1,86 @@
+---
+title: Deploy Besu across multiple Kubernetes clusters across multiple cloud providers
+description: Deploy Besu across multiple Kubernetes clusters across multiple cloud providers
+sidebar_position: 7
+tags:
+  - private networks
+---
+
+# Deploy Besu across multiple Kubernetes clusters across multiple cloud providers
+
+The following tutorial is just one of many ways to connect nodes in one K8S cluster to nodes in another K8S
+cluster across multiple cloud provider - in this case [Amazon Elastic Kubernetes Service (EKS)](https://aws.amazon.com/eks/)
+and [Azure Kubernetes Service (AKS)](https://azure.microsoft.com/en-au/products/kubernetes-service)
+
+This tutorial walks you through using AWS as the main cluster and adding an extra node in Azure to the existing pool
+
+## Overview
+
+### Steps
+
+#### 1. Create an AWC VPC 
+
+1. Use a CIDR block that doesn't overlap with that of Azure eg `10.0.0.0/16`
+2. Create the EKS cluster as normal and use the default Kubernetes service range `172.20.0.0/16`
+
+#### 2. Create an Azure Virtual Network
+
+1. Use a CIDR block that doesn't overlap with that of AWS eg `10.1.0.0/16`
+2. It is also recommended to create a subnet for the Gateway and use a CIDR of `/24` eg `10.1.1.0/24`
+3. Create the AKS cluster as normal and use the different Kubernetes service range
+ `10.2.0.0/16` (the default `10.0.0.0/16` overlaps with the AWS VPC CIDR block)
+
+#### 3. Connect the AWS VPC and Azure VNet with a site to site VPN
+
+##### 3.1 On the Azure side create a Virtual Network Gateway
+
+In the AZure VNet, create a Virtual Network Gateway with the following settings
+
+| Setting              | Value |
+|----------------------|-------------|
+| SKU                  | VpnGw2AZ (default) |
+| Gateway Type         | VPN         |
+| VPN Type             | Route-based |
+| Virtual Network      | Use the network in step 2.1 |
+| Gateway subnet       | Use the subnet from step 2.2 |
+| Public IP Address    | Create new |
+| Enable active-active mode | Disabled |
+| Configure BGP        | Disabled |
+
+The other setttings can remain as defaults or set to suit your requirements. Once this is complete
+please note down the IP address that was created for the Virtual Network Gateway
+
+##### 3.2 On the AWS side create a Customer Gateway
+
+This Customer Gateway points to the Azure Virtual Network Gateay from step 3.1 
+
+| Setting              | Value |
+|----------------------|-------------|
+| Routing              | Static |
+| IP Address           | Use the IP of the Virtual Network Gateway in step 3.1 |
+
+The other setttings can remain as defaults or set to suit your requirements
+
+##### 3.2 On the AWS side create a Virtual Private Gateway 
+
+Create an AWS Virtual Private Gateway and specify the name.
+
+| Setting              | Value |
+|----------------------|-------------|
+| ASN              | Amazon Default ASN |
+
+##### 3.3 On the AWS side attach the Virtual Private Gateway to the VPC
+
+Select the Virtual Private Gateway and then select Actions and `Attach to VPC` and select
+the VPC in step 1
+
+##### 3.4 On the AWS side create the Site to Site VPN Connection
+
+
+Create an AWS Virtual Private Gateway and specify the name.
+
+| Setting              | Value |
+|----------------------|-------------|
+| ASN              | Amazon Default ASN |
+
+