This repo links two networks together in an approximation of Dedicated Interconnect, demonstrating how to use custom routes between VPCs to force use of multiple BIG-IP instances as next-hop gateways.

1. Client instance
   • NGINX reverse-proxy configured to send all requests to backend instances in 172.17.0.0/16 network
   • Public IP, with FW rules to allow ingress from public internet
2. Service instances
   • NGINX hosting a static web page
   • No public IP, egress through control network only
3. BIG-IP instances
   • 3-NIC configuration, with interfaces in dmz, control, and service
   • Virtual Server defined on VIP(s) with Service instances as pool members
   • Forwarding rule defined on external interface (dmz)
4. client and dmz networks are connected via VPC Peering, with custom routes advertised
   • client is advertising 172.16.0.0/16 to dmz
   • dmz is advertising 172.18.0.0/16 to client
   • dmz is advertising custom route 172.17.0.0/16 with next-hop as BIG-IP VMs

1. Create the networking foundations See foundations module for example setup

2. Create/modify the Terraform environment files with required inputs

3. Execute Terraform to create the BIG-IP instance and Route

   NOTE: due to weak module dependencies, you may need to invoke this step as multiple operations so that the reserved internal IP addresses are created before the dependent resources.

   terraform init -backend-config env/ENV/poc.config
   terraform apply -var-file env/ENV/poc.tfvars -auto-approve -target google_compute_address.bigip
   terraform apply -var-file env/ENV/poc.tfvars -auto-approve

   If an error is reported that 'There is a route operation in progress on the local or peer network' repeat the last terraform apply to complete setup.

   terraform apply -var-file env/ENV/poc.tfvars -auto-approve

1. Open a browser to the public IP address of a client VM. The page will show the name of the backend service instance, and the internal IP address of whichever BIG-IP instance processed the request.
2. Refresh the page until you see a different BIG-IP address, prooving that GCP is distributing requests to all BIG-IPs.

1. Destroy resources via Terraform

   terraform destroy -var-file env/ENV/poc.tfvars -auto-approve

2. Clean up foundational resource if necessary