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Terraform Input Variables CLI Argument var

Step-01: Introduction

  • Override default variable values using CLI argument -var
  • Also learn about Terraform Plan Generation

Step-02: Input Variables Override default value with cli argument -var

  • We are going to override the default values defined in c2-variables.tf by providing new values using the -var argument using CLI
# Initialize Terraform
terraform init

# Validate Terraform configuration files
terraform validate

# Format Terraform configuration files
terraform fmt

# Option-1 (Always provide -var for both plan and apply)
# Review the terraform plan
terraform plan -var="resoure_group_name=demorg" -var="resoure_group_location=westus" -var="virtual_network_name=demovnet" -var="subnet_name=demosubnet" 

# Create Resources (optional - We are just learning concept)
terraform apply -var="resoure_group_name=demorg" -var="resoure_group_location=westus" -var="virtual_network_name=demovnet" -var="subnet_name=demosubnet"

Step-03: Generate Terraform Plan and use that using Terraform Apply

# Option-2 (Generate plan file with -var and use that with apply)
# Generate Terraform plan file
terraform plan -var="resoure_group_name=demorg" -var="resoure_group_location=westus" -var="virtual_network_name=demovnet" -var="subnet_name=demosubnet"  -out v1.plan

# Terraform Show
terraform show v1.plan

# Create / Deploy Terraform Resources using Plan file
terraform apply v1.plan

Step-04: Clean-Up Files

# Destroy Resources
terraform destroy -auto-approve
Subnet Name: demosubnet (When Prompted)

# Delete Files
rm -rf .terraform*
rm -rf terraform.tfstate*
mv v1.plan v1.plan_bkup

References