Can’t get aws lambda/DynamoDB api to work - api

Question

It is my first time trying the Aws dynamoDB and Lambda node.js. I followed exact instructions on the aws documentation here: https://docs.aws.amazon.com/apigateway/latest/developerguide/http-api-dynamo-db.html#http-api-dynamo-db-attach-integrations
Here’s the function code I used, as gotten from step 10 of the documentation
const AWS = require("aws-sdk");
const dynamo = new AWS.DynamoDB.DocumentClient();
exports.handler = async (event, context) => {
let body;
let statusCode = 200;
const headers = {
"Content-Type": "application/json"
};
try {
switch (event.routeKey) {
case "DELETE /items/{id}":
await dynamo
.delete({
TableName: "http-crud-tutorial-items",
Key: {
id: event.pathParameters.id
}
})
.promise();
body = `Deleted item ${event.pathParameters.id}`;
break;
case "GET /items/{id}":
body = await dynamo
.get({
TableName: "http-crud-tutorial-items",
Key: {
id: event.pathParameters.id
}
})
.promise();
break;
case "GET /items":
body = await dynamo.scan({ TableName: "http-crud-tutorial-items" }).promise();
break;
case "PUT /items":
let requestJSON = JSON.parse(event.body);
await dynamo
.put({
TableName: "http-crud-tutorial-items",
Item: {
id: requestJSON.id,
price: requestJSON.price,
name: requestJSON.name
}
})
.promise();
body = `Put item ${requestJSON.id}`;
break;
default:
throw new Error(`Unsupported route: "${event.routeKey}"`);
}
} catch (err) {
statusCode = 400;
body = err.message;
} finally {
body = JSON.stringify(body);
}
return {
statusCode,
body,
headers
};
};
But each time I try the API’s as it is structured on the documentation, I get ‘internal server error’. I have tried it on both terminal, and from postman, same error. I couldn’t get any helpful links elsewhere to solve this. Is there something I need to do different?

Answer 1

There are many reasons a Lambda would return a 500 exception to APIGW, for example:
https://aws.amazon.com/premiumsupport/knowledge-center/api-gateway-lambda-stage-variable-500/
https://aws.amazon.com/premiumsupport/knowledge-center/api-gateway-internal-server-error/
My suggestion is to strip back your function code, and only return a response to APIGW with no other logic and test that. Then you can decide to work forwards or backwards from there.