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Calico Cloud documentation

Cluster mesh example for clusters in AWS

Big picture​

A sample configuration for cluster mesh using AWS clusters.

Tutorial​

Set up

The cluster is installed on real hardware where node and pod IPs are routable, using an edge VPN router to peer with the AWS cluster.

A diagram showing the key configuration requirements setting up an AWS cluster (using AWS VPN CNI) peering with an on-premise cluster.

Calico Enterprise configuration

  • IP pool resource is configured for the on-premise IP assignment with IPIP is disabled
  • BGP peering to the VPN router
  • A Remote Cluster Configuration resource references the AWS cluster
  • Service discovery of the AWS cluster services uses the Calico Enterprise Federated Services Controller

Notes

  • If VPN Router is configured as a route reflector for the on-premise cluster, you would:
    • Configure the default BGP Configuration resource to disable node-to-node mesh
    • Configure a global BGP Peer resource to peer with the VPN router
  • If the IP Pool has Outgoing NAT enabled, then you must add an IP Pool covering the AWS cluster VPC with disabled set to true. When set to true the pool is not used for IP allocations, and SNAT is not performed for traffic to the AWS cluster.

AWS configuration

  • A VPC CIDR is chosen that does not overlap with the on-premise IP ranges.
  • There are 4 subnets within the VPC, split across two AZs (for availability) such that each AZ has a public and private subnet. In this particular example, the split of responsibility is:
    • The private subnet is used for node and pod IP allocation
    • The public subnet is used to home a NAT gateway for pod-to-internet traffic.
  • The VPC is peered to an on-premise network using a VPN. This is configured as a VPN gateway for the AWS side, and a classic VPN for the customer side. BGP is used for route distribution.
  • Routing table for private subnet has:
    • "propagate" set to "true" to ensure BGP-learned routes are distributed
    • Default route to the NAT gateway for public internet traffic
    • Local VPC traffic
  • Routing table for public subnet has default route to the internet gateway.
  • Security group for the worker nodes has:
    • Rule to allow traffic from the peered networks
    • Other rules required for settings up VPN peering (refer to the AWS docs for details).

To automatically create a Network Load Balancer (NLB) for the AWS deployment, we apply a service with the correct annotation.

apiVersion: v1
kind: Service
metadata:
  annotations:
    service.beta.kubernetes.io/aws-load-balancer-type: nlb
  name: nginx-external
spec:
  externalTrafficPolicy: Local
  ports:
    - name: http
      port: 80
      protocol: TCP
      targetPort: 80
  selector:
    run: nginx
  type: LoadBalancer