Oracle Cloud Reference Architecture

Overview

OCI architecture has more moving parts than AWS or Azure. Where AWS has VPC + subnets + internet gateway, OCI has VCN + regional subnets + Internet Gateway + NAT Gateway + Service Gateway + DRG (Dynamic Routing Gateway) + LPG (Local Peering Gateway) — and getting the routing tables wrong means silent packet drops with no error. This provides the standard 3-tier architecture (web/app/db) with every OCI-specific component wired correctly, plus Terraform code to deploy it.

Purpose: Produce a production-ready 3-tier OCI architecture with correctly configured networking, gateways, security rules, and compute/database tiers — deployable via Terraform.

Prerequisites

• OCI account with an active tenancy — https://cloud.oracle.com
• OCI CLI installed and configured — ~/.oci/config validated (see oraclecloud-install-auth)
• Python 3.8+ with the OCI SDK — pip install oci
• Terraform 1.5+ with the OCI provider — https://registry.terraform.io/providers/oracle/oci/latest/docs
• Compartment OCID for the target environment
• Familiarity with CIDR notation for subnet planning

Instructions

Step 1: Architecture Overview