This Terraform project simulates Fault Tolerance (FT) on OpenStack by provisioning a basic web setup with load balancing, anti-affinity, and auto-provisioned infrastructure.

openstack-ft-web/
├── environments/
│   └── dev/
│       ├── main.tf                 # Top-level config where all modules are declared
│       ├── variables.tf            # Variable definitions for dev environment
│       ├── terraform.tfvars        # Actual variable values for dev
│       ├── outputs.tf              # Consolidated outputs from modules
│       └── ankur-poc.pem           # SSH key used for provisioning (replace with your key)
│
│   └── prod/                       # For Production env
└── modules/
├── network/            # Creates network + subnet
├── router/             # Creates router and attaches subnet + sets external gw
├── security_group/     # Creates SSH (22) and HTTP (80) rules
├── instance/           # Launches 2 VMs with anti-affinity + floating IPs
├── loadbalancer/       # Sets up Octavia LB, pool, listener
└── provisioner/        # Provisions VMs via SSH using null\_resource

• Creates a custom OpenStack network and subnet
• Adds subnet to router and connects router to external gateway
• Sets up security group with inbound rules for SSH (22) and HTTP (80)
• Defines anti-affinity policy to spread VMs across hosts
• Launches 2 VMs, installs a simple webpage inside each
• Creates a load balancer (Octavia) with listener + pool pointing to the VMs
• Associates a Floating IP to the LB for external access

• Terraform ≥ 1.0
• OpenStack CLI credentials (clouds.yaml or ENV vars)
• A valid OpenStack project with required quotas
• SSH keypair to access instances

1. Clone the repo

   git clone https://github.com/ankurgautam90/openstack-ft-demo.git
   cd openstack-ft-demo/environments/dev

2. Replace SSH Key

   • Copy your SSH private key to ankur-poc.pem
   • Or edit main.tf / tfvars to point to your own key file.

3. Update Variables

   • Edit terraform.tfvars to include your:

     • auth_url, username, password, tenant_name, region, etc.
     • Network/Subnet details if different

4. Run Terraform

   terraform init
   terraform plan
   terraform apply

To delete all created resources:

terraform destroy

• This setup demonstrates fault tolerance using anti-affinity + load balancing.
• You can test FT by manually shutting down one instance and confirming webpage is still reachable.
• Webpage is provisioned using remote-exec in provisioner module.

Ankur Kumar Github | ankurgautam90 Linkedin | ankurgauti