DevOps Classroomnotes 20/May/2022

Terraform Contd…

• The two major problems with the terraform configuration code which we have written are
  • secrets are directly written (access key and secret key)
  • for creating subnets we have similar resource definition used multiple times
• Then the next set of problems are, reason for writing terraform templates are to make the infrastructure as code and reusable. But our template always
  • creates the infra in mumbai region
  • the cidr ranges are fixed
  • In my account
• Terraform aws provider configuration:
  • Refer Here
  • Lets try to install aws cli Refer Here
  • Now execute aws configure and enter access key secret access key and region ap-south-1
• Refer Here for the terraform script used to create the vpc.
• To solve the problem of using similar resource definition multiple times for subnet, first we need to make the terraform script reusable.
• In terraform to enable the parametrization of the argument values, we can use input variables Refer Here

Input Variables

• Syntax:

variable "<var-name>" {
    type            = "<type of the variable>"
    default         = "<default value>"
    description     = "description of the variable"
    validation      = "A block to validate the values"
    sensitive       = "Sensitive information"
    nullable        = "specifies if the variable can have null value"
}

• Refer Here for the variable defintions added
• We need to use the variables the syntax is var.<variable-name> Refer Here for the changes
• Now lets try to validate the terraform script
  
• To pass the variables from command line Refer Here
  
• If we have lot of variables to pass then variable defintions file is the option Refer Here.
• Refer Here
  
• Lets add more variables and Refer Here for the changes
• Now execute terraform apply -var-file "default.tfvars"