The aws cli to create a IAM policy, create a user, create access key, and attach the user to the policy

aws-cli-create-iam-policy-and-user.txt

# The code for the backend-role-policy.json is available at https://gist.github.com/kunduso/bf94f1aa5e683ed66539458a9a44138d
# create a policy with name "Custom-Terraform-Policy-Backend-April"
# https://docs.aws.amazon.com/cli/latest/reference/iam/create-policy.html
aws iam create-policy --policy-name Custom-Terraform-Policy-Backend-April --policy-document file://backend-role-policy.json

#output
{                                                                                                                                  
    "Policy": {
        "PolicyName": "Custom-Terraform-Policy-Backend-April",
        "PolicyId": "ANPAZIAA3LP6OBWQHE5E6",
        "Arn": "arn:aws:iam::$(AWSAccountNumber):policy/Custom-Terraform-Policy-Backend-April",
        "Path": "/",
        "DefaultVersionId": "v1",
        "AttachmentCount": 0,
        "PermissionsBoundaryUsageCount": 0,
        "IsAttachable": true,
        "CreateDate": "2021-04-01T18:45:25+00:00",
        "UpdateDate": "2021-04-01T18:45:25+00:00"
    }
}

# Create a user with name Terraform-User
# https://docs.aws.amazon.com/cli/latest/reference/iam/create-user.html
aws iam create-user --user-name Terraform-User

#output
{
    "User": {
        "Path": "/",
        "UserName": "Terraform-User",
        "UserId": "AIDAZIAA3LP6FKZZCFBD5",
        "Arn": "arn:aws:iam::$(AWSAccountNumber):user/Terraform-User",
        "CreateDate": "2021-04-01T18:54:27+00:00"
    }
}

# Create access key for the user with name Terraform-User
# https://docs.aws.amazon.com/cli/latest/userguide/cli-services-iam-create-creds.html
aws iam create-access-key --user-name Terraform-User

#output
{
    "AccessKey": {
        "UserName": "Terraform-User",
        "AccessKeyId": "$(AccessKeyId-For-This-User)",
        "Status": "Active",
        "SecretAccessKey": "$(SecretAccessKey-For-This-User)",
        "CreateDate": "2021-04-01T18:56:47+00:00"
    }
}

# Attach a policy with policy ARN to a user with name Terraform-User
# https://docs.aws.amazon.com/cli/latest/reference/iam/attach-user-policy.html
aws iam attach-user-policy --policy-arn arn:aws:iam::$(AWSAccountNumber):policy/Custom-Terraform-Policy-Backend-April --user-name Terraform-User

# No output if user successfully attached to a policy