recursionDetectionMiddleware.js•1.28 kB
import { InvokeStore } from "@aws/lambda-invoke-store";
import { HttpRequest } from "@smithy/protocol-http";
const TRACE_ID_HEADER_NAME = "X-Amzn-Trace-Id";
const ENV_LAMBDA_FUNCTION_NAME = "AWS_LAMBDA_FUNCTION_NAME";
const ENV_TRACE_ID = "_X_AMZN_TRACE_ID";
export const recursionDetectionMiddleware = () => (next) => async (args) => {
const { request } = args;
if (!HttpRequest.isInstance(request)) {
return next(args);
}
const traceIdHeader = Object.keys(request.headers ?? {}).find((h) => h.toLowerCase() === TRACE_ID_HEADER_NAME.toLowerCase()) ??
TRACE_ID_HEADER_NAME;
if (request.headers.hasOwnProperty(traceIdHeader)) {
return next(args);
}
const functionName = process.env[ENV_LAMBDA_FUNCTION_NAME];
const traceIdFromEnv = process.env[ENV_TRACE_ID];
const invokeStore = await InvokeStore.getInstanceAsync();
const traceIdFromInvokeStore = invokeStore?.getXRayTraceId();
const traceId = traceIdFromInvokeStore ?? traceIdFromEnv;
const nonEmptyString = (str) => typeof str === "string" && str.length > 0;
if (nonEmptyString(functionName) && nonEmptyString(traceId)) {
request.headers[TRACE_ID_HEADER_NAME] = traceId;
}
return next({
...args,
request,
});
};