Trigger a lambda function after a rest api is accessed

Question

I have a rest API in aws api gateway that access's an external http endpoint and returns some data.

Every time this rest api is accessed and returns data, i need to trigger a lambda function that uses the data returned by the rest api. How can i achieve that ?

Tried looking for answers on this and all of them point to how to trigger a lambda function using a rest api.

Answer 1

You can do this in 2 ways.

1. When a request is sent to api gateway, invoke a lambda, inside this lambda access your external http endpoint and whatever the result comes, invoke another lambda.

something like this.

const invoke = async (funcName, payload) => {
  const client = createClientForDefaultRegion(LambdaClient);
  const command = new InvokeCommand({
    FunctionName: funcName,
    Payload: JSON.stringify(payload),
    LogType: LogType.Tail,
  });

  const { Payload, LogResult } = await client.send(command);
  const result = Buffer.from(Payload).toString();
  const logs = Buffer.from(LogResult, "base64").toString();
  return { logs, result };
};

2. Use stepfunctions with api gateway ( which would be similar to 1st operation)