# Assignment
The Nautilus DevOps team needs to set up a DynamoDB table for storing user data. They need to create a DynamoDB table with the following specifications:

1) The table name should be nautilus-users.

2) The primary key should be nautilus_id (String).

3) The table should use PAY_PER_REQUEST billing mode.

Use Terraform to create this DynamoDB table. The Terraform working directory is /home/bob/terraform. Create the main.tf file (do not create a different .tf file) to create the DynamoDB table.

Note: Right-click under the EXPLORER section in VS Code and select Open in Integrated Terminal to launch the terminal.

# Solution

# DynamoDB Table — `nautilus-users`

Terraform solution to create an on-demand DynamoDB table keyed on a string
partition key.

## `main.tf`

```hcl
terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 6.0"
    }
  }
}

provider "aws" {
  region = "us-east-1"
}

resource "aws_dynamodb_table" "nautilus_users" {
  name         = "nautilus-users"
  billing_mode = "PAY_PER_REQUEST"
  hash_key     = "nautilus_id"

  attribute {
    name = "nautilus_id"
    type = "S"
  }
}
```

## How to run

```bash
cd /home/bob/terraform
terraform init
terraform apply -auto-approve
```

## How it works

### `aws_dynamodb_table`

A single resource provisions the whole table.

- **`name = "nautilus-users"`** — the table name, exactly as required.

- **`hash_key = "nautilus_id"`** — sets the table's **partition key** (DynamoDB's
  API calls it the "hash key"). This is the primary key the task asks for. No
  `range_key` is defined, so `nautilus_id` alone uniquely identifies each item — a
  simple primary key rather than a composite one.

- **`attribute` block** — this is the part people forget. DynamoDB is schemaless for
  non-key fields, so you only ever declare attributes that participate in a key
  (partition key, sort key, or an index key). Here `nautilus_id` is the partition
  key, so it **must** be declared with its type. `type = "S"` marks it as a
  **String** (the valid types are `S` string, `N` number, `B` binary). Referencing a
  `hash_key` without a matching `attribute` block fails validation with
  "all attributes must be indexed."

- **`billing_mode = "PAY_PER_REQUEST"`** — puts the table in **on-demand** mode.
  You pay per read/write request with no capacity to provision or manage, and
  DynamoDB auto-scales to traffic. Because of this mode, the `read_capacity` /
  `write_capacity` arguments are **omitted** — they're only valid (and required)
  under `PROVISIONED` billing. Setting them here would be a config error.

### Why on-demand fits here

Beyond being the task requirement, `PAY_PER_REQUEST` is the simplest correct choice:
no throughput math, no capacity planning, and it avoids the low provisioned-capacity
caps that constrained sandbox environments impose on `PROVISIONED` tables. The table
comes up ready to take reads and writes immediately.

## Verify

```bash
aws dynamodb describe-table --table-name nautilus-users \
  --query 'Table.{Name:TableName,Billing:BillingModeSummary.BillingMode,Key:KeySchema,Attrs:AttributeDefinitions,Status:TableStatus}'
```

Expected — `BillingMode: PAY_PER_REQUEST`, a key schema with `nautilus_id` as
`HASH`, an attribute definition of `nautilus_id` type `S`, and `TableStatus: ACTIVE`
(the table takes a few seconds to transition from `CREATING` to `ACTIVE`).