ibm-ecommerce-infra

Terraform infrastructure as code that provisions an IBM Cloud VPC web tier with an autoscaling instance group, a public load balancer, and a managed PostgreSQL database.

Note

This is a working learning and demo project. It builds the network, compute, load balancing, and database layers for an ecommerce style web tier on IBM Cloud. A few resources are intentionally commented out in the code (a standalone instance and a load balancer pool member). The autoscale manager is created but disabled by default. See Roadmap and Configuration for details.

Table of Contents

• About
• What It Provisions
• Tech Stack
• Architecture
• Getting Started
• Usage
• Variables
• Project Structure
• Configuration
• Roadmap
• Contributing
• License

About

ibm-ecommerce-infra is a Terraform configuration for IBM Cloud. It stands up the core infrastructure that a simple web application would need: a private network, a pool of identical web servers that can scale, a public load balancer in front of them, and a managed PostgreSQL database for application data.

The whole stack is defined as code across a handful of .tf files. You supply an IBM Cloud API key and an SSH public key, then run the standard Terraform workflow to create everything in one go. The default region is eu-gb (London).

The repository is single environment and does not configure a remote state backend, so Terraform keeps state locally by default.

What It Provisions

• VPC named ecommerce-vpc in the Default resource group.
• A subnet (ecommerce-subnet) with 256 IPv4 addresses in zone <region>-1.
• An SSH key (web-server-ssh) built from your supplied public key.
• A compute instance template (web-template) using the cx2-2x4 profile and an Ubuntu 22.04 minimal image.
• An instance group (web-asg) that runs 2 instances and registers them with the load balancer pool on port 80.
• An instance group manager (web-asg-manager) of type autoscale, with membership between 2 and 5. It is created with enable_manager = false, so autoscaling is off until you turn it on.
• A public application load balancer (web-lb).
• A load balancer pool (web-pool) using round robin with an HTTP health check on /.
• A load balancer listener (web-listener) on port 80 over HTTP.
• A managed PostgreSQL database (ecommerce-db) using IBM Databases for PostgreSQL on the standard plan with a public service endpoint.

Tech Stack

Layer	Technology
IaC tool	Terraform (HCL)
Cloud	IBM Cloud
Provider	IBM-Cloud/ibm (>= 1.60.0, locked at 1.77.0)
Network	IBM Cloud VPC, subnet
Compute	VPC instance template, instance group, instance group manager
Load balancing	VPC application load balancer, pool, listener
Database	IBM Databases for PostgreSQL
OS image	Ubuntu 22.04 minimal (amd64)

Architecture

flowchart TD
    Internet([Internet]) -->|HTTP :80| LB[Public Load Balancer web-lb]
    LB --> Listener[Listener :80]
    Listener --> Pool[Pool web-pool round_robin]

    subgraph VPC[ecommerce-vpc]
        subgraph Subnet[ecommerce-subnet 256 IPs]
            Pool --> ASG[Instance Group web-asg count 2]
            Template[Instance Template web-template cx2-2x4] --> ASG
            Manager[Group Manager autoscale 2 to 5 disabled] -.-> ASG
        end
    end

    ASG --> DB[(Databases for PostgreSQL ecommerce-db)]
    SSH[SSH Key web-server-ssh] --> Template
    Image[Ubuntu 22.04 image] --> Template

Loading

Getting Started

Prerequisites

• Terraform installed.
• An IBM Cloud account and an IBM Cloud API key.
• The IBM Cloud CLI (optional, useful for checking resources).
• An SSH public key for access to the instances.

Setup

git clone https://github.com/atiqbitstream/ibm-ecommerce-infra.git
cd ibm-ecommerce-infra

Provide the required variables. The simplest way is a terraform.tfvars file (it is git-ignored, so it stays out of version control):

ibmcloud_api_key = "your-ibm-cloud-api-key"
ssh_public_key   = "ssh-rsa AAAA... your-public-key"
region           = "eu-gb"

Usage

Run the standard Terraform workflow:

terraform init
terraform plan
terraform apply

To tear everything down:

terraform destroy

Variables

Variable	Description	Type	Default
ibmcloud_api_key	IBM Cloud API key, used by the provider to authenticate.	string (sensitive)	none, required
ssh_public_key	Public SSH key for accessing the instances.	string (sensitive)	none, required
region	IBM Cloud region the resources are created in.	string	eu-gb

Project Structure

ibm-ecommerce-infra/
├── provider.tf          # IBM provider and Terraform required_providers block
├── variables.tf         # Input variables (API key, SSH key, region)
├── vpc.tf               # VPC, subnet, SSH key, image and resource group data
├── auto_scaling.tf      # Instance template, instance group, group manager
├── load_balancer.tf     # Load balancer, pool, and listener
├── database.tf          # Databases for PostgreSQL instance
├── infra-graph.svg      # Rendered dependency graph of the resources
├── .terraform.lock.hcl  # Provider dependency lock file
└── .gitignore           # Ignores state, .tfvars, and local Terraform files

Configuration

A few things are worth knowing before you apply:

• Autoscaling is off by default. The instance group manager is created with enable_manager = false. The group runs a fixed count of 2 instances until you enable the manager. Note that IBM Cloud does not allow changing the instance count manually while the autoscale manager is active.
• Commented out resources. A standalone ibm_is_instance web server and an ibm_is_lb_pool_member resource are present in the code but commented out. The instance group already attaches members to the pool, so the pool member resource is not needed in the active configuration.
• Database credentials. The PostgreSQL admin password is currently hardcoded in database.tf. This should be replaced with a variable (see Roadmap). Do not reuse the committed value.
• Service endpoint. The database uses a public service endpoint. For production you would typically use private endpoints.
• State. No remote backend is configured, so state is stored locally. For team use, configure a remote backend.

Roadmap

• Move the database admin password out of database.tf into a sensitive variable.
• Add a remote state backend for team and CI use.
• Add output values for the load balancer hostname and database connection details.
• Enable the autoscale manager and tune scaling policies.
• Switch the database to a private service endpoint.
• Add a separate .tfvars example file and per environment workspaces.

Contributing

Contributions are welcome. Open an issue to discuss a change, or send a pull request. Please keep Terraform formatting consistent by running terraform fmt before submitting.

License

Distributed under the MIT License. See LICENSE.