Terraform Modules

Links: 113 Terraform Index

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Modules

• Our terraform configuration file is becoming increasingly long making it difficult to read and manage.
• We can split the configuration into multiple configuration files and it will work the same way.
  • Terraform will consider all files with .tf extension as configuration files.
  • This approach limits the reusability of the code.
• Using modules:
  • 
  • We can also use absolute path to the child module.
  • Here dev-webserver is the logical name of the module.

Creating and Using modules

• Creating the module
  • 
  • The variables will come from the terraform file using the modules

• Using the module

  • 
  • Providing the bucket variable name would have overwritten the default bucket value
  • We run terraform init and terraform apply in the us payroll directory and not the module.
  • When we run terraform init it downloads our module from source along with the AWS plugin.
  • Referring the payroll db:
    • 

• Modules are comparable to libraries or packages in other programming languages.

• Having certain components of the infra fixed (like in the above case DynamoDB table name in different regions) ensures provisioning process maintains a standard configuration.

Using modules from the public terraform registry

• The module that we built above is a local module.
• The terraform registry is used to store provider plugins (like AWS) and modules.
• The modules can be categorised into 2 types:
  • Verified
  • Community
• The instructions on how to use the terraform modules can be found on the registry.
• To download the module we can use terraform get after using it in our configuration file.
• It is a good idea to specify the version of the module while using it.
  • Not specifying the version will always download the latest version from the registry.

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Last updated: 2023-01-14