Correspondents/.open-next/cloudflare/skew-protection.js
2025-11-13 22:33:26 -07:00

37 lines
1.4 KiB
JavaScript

import process from "node:process";
const DEPLOYMENT_MAPPING_ENV_NAME = "CF_DEPLOYMENT_MAPPING";
const CURRENT_VERSION_ID = "current";
let deploymentMapping;
function maybeGetSkewProtectionResponse(request) {
if (false) {
const url = new URL(request.url);
if (url.hostname === "localhost" || url.hostname.endsWith(".workers.dev")) {
return void 0;
}
const requestDeploymentId = request.headers.get("x-deployment-id") ?? url.searchParams.get("dpl");
if (!requestDeploymentId || requestDeploymentId === process.env.DEPLOYMENT_ID) {
return void 0;
}
deploymentMapping ??= process.env[DEPLOYMENT_MAPPING_ENV_NAME] ? JSON.parse(process.env[DEPLOYMENT_MAPPING_ENV_NAME]) : {};
if (!(requestDeploymentId in deploymentMapping)) {
return void 0;
}
const version = deploymentMapping[requestDeploymentId];
if (!version || version === CURRENT_VERSION_ID) {
return void 0;
}
const versionDomain = version.split("-")[0];
const hostname = `${versionDomain}-${process.env.CF_WORKER_NAME}.${process.env.CF_PREVIEW_DOMAIN}.workers.dev`;
url.hostname = hostname;
const requestToOlderDeployment = new Request(url, request);
const headers = new Headers(request.headers);
headers.delete("origin");
return fetch(requestToOlderDeployment, { headers });
}
}
export {
CURRENT_VERSION_ID,
DEPLOYMENT_MAPPING_ENV_NAME,
maybeGetSkewProtectionResponse
};