How can I use the terraform for creating and managing IAM policy documents, and defining permission for a research project?

 In the first context of AWS, Here is the approach given of how you can create and manage AWS IAM policy document, define permission, and ensure security best practices.

Creating IAM policy document with Terraform

You can use the aws_iam_policy_document of terraform data source or Resources by defining the IAM policy document in JSON format.

Data “aws_iam_policy_document” “example_policy” {
  Statement {
    Actions   = [“s3:GetObject”]
    Resources = [“arn:aws:s3:::example-bucket/*”]
  }
  Statement {
    Actions   = [“ec2:Describe*”]
    Resources = [“*”]
  }
}
Defining permission and attaching policies to IAM roles/users/groups
You can use the aws_iam_policy and aws_iam_policy_attachement of terraform resource by defining IAM policies and attaching them for IAM roles, users, or group.
Resource “aws_iam_policy” “example_policy” {
  Name        = “ExamplePolicy”
  Description = “Example IAM policy”
  Policy      = data.aws_iam_policy_document.example_policy.json
}
Resource “aws_iam_role” “example_role” {
  Name               = “ExampleRole”
  Assume_role_policy = <