2.3. Review the Terraform Configuration Files

You will now review the Terraform configuration files to understand what they do.

2.3.1. Terraform Directory

The terraform directory contains all of the configuration files needed to deploy the lab environment in AWS.

1. In the VS Code terminal, list the Terraform directory.

   ls terraform
   

   

   You should see several Terraform (*.tf) files listed. The various components of the lab are deployed via separate configuration files to make it easier to manage.

   ami-search.tf           bigip2.tf                          ha-via-lb            postman-env-file.tf       vpc-app.tf
   appserver1.tf           certs.tf                           internet-gateway.tf  securitygroups.tf         vpc-hub.tf
   appserver2.tf           cfe-dependencies.tf                jumphost-ip.tf       templates
   as3declaration-file.tf  cloudwatch.tf                      locals.tf            terraform.tfvars.example
   bigip-vips.tf           credentials.tf                     main.tf              transit-gateway.tf
   bigip1.tf               f5extension-importdevices-file.tf  nat-gateway.tf       variables.tf
   

   

2.3.2. View Terraform Files

1. Review these files with VS Code by executing the following:

   code .
   

   

   ‘code’ + <space> + <dot>

   Wait for VS Code to launch a new window and display the project directory in the left panel.

   
   

   Tip

   If the font is too small or too large, you can adjust the size by pressing <CTRL-+> (control-plus) or <CTRL–> (control-minus).

   
   

2. Click on the terraform directory to expand it.

3. Click on each file that corresponds to the sections below. VS Code provides Terraform syntax highlighting when the HashiCorp Terraform extension is installed.

2.3.3. Terraform Providers

Providers enable configuration of dependencies for resource providers (e.g., minimum version for AWS, Azure).

Providers

Filename	Description
main.tf	Defines the AWS Terraform Provider dependencies.

2.3.4. Terraform Variables

Variables allow you to create flexible and scalable Terraform deployments by eliminating hardcoded values in each configuration file.

Terraform Variables

Filename	Description
variables.tf	Defines all Terraform variables (and some default values) used in the other configuration files.
terraform.tfvars.example	Examples of explicitly configured Terraform variable values. This is a template for your own terraform.tfvars file, which will set (or override) values for the variables defined in the variables.tf file.

2.3.5. Virtual Network

Network objects types are defined in separate Terraform configuration files.

Virtual Network Deployment

Filename	Description
vpc-hub.tf	Creates the hub VPC, subnets, and route tables (to Internet and app VPC).
vpc-app.tf	Creates the app VPC, subnets, and route tables.
transitgateway.tf	Creates the Transit Gateway to route traffic between the hub and app VPCs. This simplifies the peering of VPCs.
internet-gateway.tf	Creates the Internet Gateway. A route table in the vpc-hub.tf file defines a default route to the Internet Gateway. An Internet Gateway provides external access to resources within the VPCs.
nat-gateway.tf	Creates the NAT Gateway for outbound Internet access from the application subnet. This is needed for the app servers to perform their onboarding. A route table in the vpc-hub.tf file is associated with the ‘internal’ subnet to send app server outbound traffic to the Internet Gateway.
securitygroups.tf	Creates the network Security Groups that control access to/from the VPC Subnets. A Security Group protects the BIG-IP public management IP - allowing only connections from your jump host’s public IP address.
bigip-vips.tf	Creates an Elastic IP address (EIP) / public IP and associates it to a private BIG-IP Virtual IP Address. This allows Internet clients to reach a BIG-IP Virtual Server.

Note

Access to lab Public IPs is restricted by a Security Group that contains your jump host public IP address.

2.3.6. EC2 Instances

Each EC2 VE instance is defined in a separate Terraform file.

EC2 VM Deployment

Filename	Description
ami-search.tf	Creates Terraform data sources containing the Amazon Machine Image (AMI) IDs for the BIG-IP VE and Linux app server EC2 instances. They are filtered based on the f5_ami_search_name and linux_ami_search_name variables. The most recent image version is selected When multiple AMI IDs are returned.
credentials.tf	Creates an AWS Key Pair for SSH access to BIG-IPs and Linux app servers. A copy of these values will also be stored locally (f5lab.key, f5lab.pub) Also creates a random 16-character password for the BIG-IP admin user account (used for BIG-IP GUI access).
appserver1.tf	Deploys a demo application server instance in AZ1 of the app VPC. Creates a Network interface (app_az1 subnet).
appserver2.tf	Deploys a demo application server instance in AZ2 of the app VPC. Creates a Network interface (app_az2 subnet).
bigip1.tf	Deploys a BIG-IP VE instance in AZ1 of the hub VPC. Creates the following: 3 Network interfaces (hub_bigip1_mgmt, hub_bigip1_external, hub_bigip1_internal) An EIP / public IP that is associated with the BIG-IP’s private management self IP to provide remote administration access). F5 onboarding configuration (BIG-IP Runtime Init and F5 Automation Toolchain extensions)
bigip2.tf	Deploys a BIG-IP VE instance in AZ2 of the hub VPC. Creates the following: 3 Network interfaces (hub_bigip1_mgmt, hub_bigip1_external, hub_bigip1_internal) An EIP / public IP that is associated with the BIG-IP’s private management self IP to provide remote administration access. F5 onboarding configuration (BIG-IP Runtime Init and F5 Automation Toolchain extensions)

Note

Access to the lab BIG-IP Management Public IPs is restricted by a Security Group that contains your jump host public IP address.

2.3.7. F5 Automation

The base system settings and network configuration are provisioned using F5 Automation Toolchain extensions.

BIG-IP Onboarding

Filename

Description

templates/f5_onboard_3nic_custom.tmpl

Template for rendering BIG-IP Runtime Init and Declarative Onboarding configuration data. A cloud-init script is created that will: Install and executes the BIG-IP Runtime Init onboarding tool Install F5 Automation Toolchain extension packages for DO, AS3, CFE, and TS Deploy a DO declaration to configure the base system settings (glboal settings, admin user/password, SSH key, resource provisioning, etc) and network settings (3 interfaces, VLANs, self IPs, routes) The bigip1.tf and bigip2.tf files reference this template to generate their onboarding configuration file. The rendered template output will be saved to local files (bigip1_f5_onboard.rendered and bigip2_f5_onboard.rendered) which you can view after applying the Terraform. See the following links for more details: f5-bigip-runtime-init f5-declarative-onboarding

App Deployment with AS3

Filename	Description
certs.tf	Creates ECDSA key and certificate files (example01a.f5lab.dev.key, example01a.f5lab.dev.cert, example01b.f5lab.dev.key, example01b.f5lab.dev.cert)
as3declaration-file.tf	Creates an AS3 declaration file with ECDSA certificates. This is used with the F5 VS Code Extension.
f5extension-importdevices-file.tf	Creates a JSON file containing the BIG-IP public management IP addresses. This is used with the F5 VS Code Extension.

HA via API with CFE

Filename	Description
cfe-dependencies.tf	Creates an S3 Bucket and IAM policy for use with the Cloud Failover Extension.

HA via LB

Filename	Description
ha-via-lb/nlb.tf	Creates an AWS Network Load Balancer for BIG-IP HA failover

Telemetry Streaming

Filename	Description
cloudwatch.tf	Creates Amazon CloudWatch resources for analytics integration.

2.3.8. Miscellaneous

Additional Terraform files are included to support this lab.

Miscellaneous Configuration

Filename	Description
jumphost-ip.tf	Determines the jump host’s public IP address. Referenced by the security groups that restrict access to the lab Public IPs.
postman-env-file.tf	Creates a Postman environment variables file based on Terraform variables and dynamic data.
templates/f5lab_postman_env_template.json	Template for the Postman environment variables file that is generated by postman-env-file.tf.

2.3.9. Terraform Outputs

Output values are included in some of the Terraform files (rather than consolidated in a separate outputs.tf file). The outputs are covered in the next section.