[SOLVED] How do I grant access for a Lambda to read and or write to a DynamoDB table using CDK?

How do I grant access for a Lambda to read and or write to a DynamoDB table using CDK?

I am using AWS CDK to set up a simple CRUD webservice, where a set of lambdas will read and write to a DynamoDB table.

The suggestion from ChatGPT was to set up access like so:

// Create a DynamoDB table
const table = new dynamodb.Table(scope, utils.prefixed('stable-diffusion'), {
    partitionKey: { name: 'ID', type: dynamodb.AttributeType.STRING },
    // sortKey: { name: 'SK', type: dynamodb.AttributeType.STRING },
    billingMode: dynamodb.BillingMode.PAY_PER_REQUEST, // use pay-per-request billing mode
    removalPolicy: cdk.RemovalPolicy.DESTROY, // delete the table when the stack is deleted
    // timeToLiveAttribute: 'ttl', // enable TTL for items in the table
    tableName: utils.prefixed('stable-diffusion'), // optional: specify a custom table name
});

// Add an IAM policy to allow read and write access to the table
const policy = new iam.PolicyStatement({
    effect: iam.Effect.ALLOW,
    actions: ['dynamodb:GetItem', 'dynamodb:PutItem', 'dynamodb:DeleteItem'],
    resources: [table.tableArn],
});
table.grantReadWriteData(policy);

However this gives me the error: "Argument of type 'PolicyStatement' is not assignable to parameter of type IGrantable.

What is the correct way to achieve this?

Solution

I'm not on my laptop to double check this for you, but I usually do something like the following:

// myTable definition
// myLambda definiton

myTable.grantReadWriteData(myLambda)