Since AWS services are paid-for, it's better to bootstrap a local instance of the DynamoDB database for development or testing your application. There is an image of DynamoDB on Docker Hub. Run the instance with this command:

docker run -it --rm --name test-dynamodb -p 8000:8000 amazon/dynamodb-local

This command creates an instance of a database and forwards port 8000 of a container to a local port with the same number.

To work with this database instance, you need the AWS CLI tool. This can be installed using the instructions from https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-install.html. On Linux, I use the following command:

pip install awscli --upgrade --user

This command doesn't need administration privileges to be installed. After I installed the tool, I created a user with programmatic access, as detailed here: https://console.aws.amazon.com/iam/home#/users$new?step=details. You can read more about creating a user account to access the AWS API here: https://docs.aws.amazon.com/IAM/latest/UserGuide/getting-started_create-admin-group.html.

When you have a user for programmatic access, you can configure the AWS CLI using the configure subcommand:

aws configure
AWS Access Key ID [None]: <your-access-key>
AWS Secret Access Key [None]: <your-secret-key>
Default region name [None]: us-east-1
Default output format [None]: json

The subcommand asks you for your user credentials, default region, and desired output format. Fill in those fields as appropriate.

Now, we can create a table using the AWS CLI tool. Enter the following command into the console:

aws dynamodb create-table --cli-input-json file://table.json --endpoint-url http://localhost:8000 --region custom

This command creates a table from a declaration in JSON format from the table.json file in the local database, with an endpoint of localhost:8000. This is the address of the container we have started. Look at the contents of this table declaration file:

{
    "TableName" : "Locations",
    "KeySchema": [
        {
            "AttributeName": "Uid",
            "KeyType": "HASH"
        },
        {
            "AttributeName": "TimeStamp",
            "KeyType": "RANGE"
        }
    ],
    "AttributeDefinitions": [
        {
            "AttributeName": "Uid",
            "AttributeType": "S"
        },
        {
            "AttributeName": "TimeStamp",
            "AttributeType": "S"
        }
    ],
    "ProvisionedThroughput": {
        "ReadCapacityUnits": 1,
        "WriteCapacityUnits": 1
    }
}

This file contains a declaration of a table with two required attributes:

• Uid - This stores user identifiers. This attribute will be used as a partition key.
• TimeStamp - This stores a timestamp when location data is produced. This attribute will be used as a sorting key to order records.

You can check whether the database instance contains this new table with the following command:

aws dynamodb list-tables --endpoint-url http://localhost:8000 --region custom

It prints the list of tables that the database instance contains, but our list is rather short, as we only have one table:

{
    "TableNames": [
        "Locations"
    ]
}

The database is prepared. Now, we will create a tool to add records to this table using Rust.