Terraform automation script for an availability zone

Description

This solution provides an automated solution for deploying a resilient infrastructure for a 3-tier web application in an availability zone. It contains: Terraform scripts to deploy VSIs, LBaaS, subnets, security groups, VPN, public gateway, and COS. Some resources are optional. User-data to install LAMP stack. (optional)

Architecture

The solution is broken into two parts -- core and optional modules. The core module is mandatory and consists of: VSIs with anti-affinity (placement groups) for each tier -- web, app, and DB. DB has a secondary data volume. Bastion server with a floating IP for management and access to other VSIs. Each tier is in their own private subnet with security groups. Both web and app tiers are front-end with an LBaaS The optional module allows users to enable the following resources: Public or private connectivity for the web LBaaS. VPN for remote connectivity. Autoscale to optimize VSI resource and cost for web and app tier. COS for additional storage. Public gateway for private subnets (web, app, and DB) for outbound traffic to the internet. LAMP stack installation.

Input parameter file

Most edits are contained within the example.userinput.auto.tfvars file. You can enter the VSI image of choice or profile. The secondary data volume size parameter for DB is located in the db_variables.tf For resources listed as optional, you do not need to edit unless you have set it for true.

Security groups or LBaaS listening ports are configured with default ports (i.e., 22, 80, and 443). If additional modifications are required, then it is recommended to do it after provisioning through IBM Cloud UI or CLI.

Usage

1. Clone the gh repo to your machine.
2. Change directory to the location where you cloned the vpc-ha-az to.
3. Change directory to saz sub-folder.
4. Edit the example.userinput.auto.tfvars.
   1. The default size for the data volume for DB is 10GB. To change the size edit the parameter in the db_variables.tf file.
5. Issue terraform init.
6. Issue terraform plan.
7. Issue terraform apply.
8. To destroy
   1. The bastion server is protected for inadvertent deletion. You need to change the prevent_destroy parameter to false. It is located at /.ha_saz_core_module/saz/core_modules/bastion_compute.tf.
   2. Issue terraform destroy.

Related Links

Customizing a three-tier highly available infrastructure VPC in a single availability zone with automation