Instead, fetch alternates from within the feed on the demand.
This makes alternates marginally more expensive to retrieve, but saves on storage (which we were running out on the DigitalOcean deployment), and is a cleaner architecture overall: no need to keep the feeds and alternates in sync.
Here’s a script to migrate existing feeds:
// Call me with, for example: env "BASE_URL=https://kill-the-newsletter.com" npx ts-node migrate.ts
// I’m idempotent and reentrant, you may call me multiple times if necessary (for example, if the migration fails in the middle for whatever reason)
import { promises as fs } from "fs";
import path from "path";
import { JSDOM } from "jsdom";
const BASE_URL = process.env.BASE_URL ?? "http://localhost:8000";
const FEEDS_PATH = "static/feeds";
(async () => {
await fs.rmdir("static/alternate", { recursive: true });
for (const feedPath of (await fs.readdir(FEEDS_PATH)).filter((feedPath) =>
feedPath.endsWith(".xml")
)) {
const text = await fs.readFile(path.join(FEEDS_PATH, feedPath), "utf-8");
const feed = new JSDOM(text, { contentType: "text/xml" });
const document = feed.window.document;
const feedIdentifier = document
.querySelector("id")!
.textContent!.split(":")[2];
for (const entry of document.querySelectorAll("entry")) {
const entryIdentifier = entry
.querySelector("id")!
.textContent!.split(":")[2];
entry
.querySelector(`link[rel="alternate"]`)
?.setAttribute(
"href",
`${BASE_URL}/alternate/${feedIdentifier}/${entryIdentifier}.html`
);
}
await fs.writeFile(
path.join(FEEDS_PATH, feedPath),
`<?xml version="1.0" encoding="utf-8"?>${feed.serialize()}`.trim()
);
console.log(feedIdentifier);
}
})();
Leandro Facchinetti
Johan Holmerin