Website Uptime Tracker

Examples from the community:

View and run this example on Val Town

import { email } from "https://esm.town/v/std/email?v=11";
import { sqlite } from "https://esm.town/v/std/sqlite?v=6";

await sqlite.execute(
  "CREATE TABLE IF NOT EXISTS uptime (id INTEGER PRIMARY KEY AUTOINCREMENT, url TEXT, ok INTEGER, reason TEXT, status INTEGER, duration INTEGER, timestamp DATETIME DEFAULT CURRENT_TIMESTAMP);",
);

export async function uptimeCheck(url: string) {
  let ok = true;
  let reason: string;
  let status: number;
  let start: number;
  let end: number;
  start = performance.now();
  try {
    const res = await fetch(url);
    end = performance.now();
    status = res.status;
    if (res.status === 200) {
      console.log(`Website up (${url}): ${res.status} (${end - start}ms)`);
    } else {
      ok = false;
      console.log(`Website down (${url}): ${res.status} (${end - start}ms)`);
    }
  } catch (e) {
    end = performance.now();
    reason = `couldn't fetch: ${e}`;
    ok = false;
    console.log(`Website down (${url}): ${reason} (${end - start}ms)`);
  }
  if (!ok) {
    email({ subject: `Website down (${url})` });
  }
  await sqlite.execute(
    {
      sql: "INSERT INTO uptime (url, ok, reason, status, duration) VALUES (?, ?, ?, ?, ?)",
      args: [url, ok ? 1 : 0, reason, status, end - start],
    },
  );
}

export default async () => {
  ["https://jonnie.com", "https://faith.tools/"].forEach(uptimeCheck);
};

View and run this example on Val Town

let { twitterAPIDown } = await import("https://esm.town/v/stevekrouse/twitterAPIDown");
import process from "node:process";
import { msHour } from "https://esm.town/v/stevekrouse/msHour";
import { twitterSearch } from "https://esm.town/v/stevekrouse/twitterSearch";

// let's poll the elevated v2 twitter api
// until it's down, and store the state in
// @stevekrouse.twitterAPIDown ({ down: boolean, reason: string})
export async function checkIfTwitterAPIIsDown() {
  try {
    // query for something we know will return results
    const results = await twitterSearch({
      query: '"hello"',
      start_time: new Date(Date.now() - 1 * msHour),
      bearerToken: process.env.twitter,
    });
    if (results.length) {
      // if we get results, the API is still up
      twitterAPIDown = {
        down: false,
        reason: `search returned ${results.length} results at ${new Date()}`,
      };
    } else {
      // no results = API down
      twitterAPIDown = {
        down: true,
        reason: `search returned ${results.length} results at ${new Date()}`,
      };
    }
  } catch (e) {
    // if there's an error, the API is also likely down
    twitterAPIDown = {
      down: false,
      reason: `search errored ${e.message} at ${new Date()}`,
    };
    throw e; // so it shows up in tracing as an error
  }
}

View and run this example on Val Town

import { diffHtml } from "https://esm.town/v/chet/diffHtml";
import { blob } from "https://esm.town/v/std/blob?v=11";
import { email } from "https://esm.town/v/std/email?v=11";
import { fetch } from "https://esm.town/v/std/fetch";

export async function watchWebsite(url: string) {
  const newHtml = await fetch(url).then(r => r.text());

  const key = "watch:" + url;
  let oldHtml = "";
  try {
    oldHtml = await blob.get(key).then(r => r.text());
  } catch (error) {}

  await blob.set(key, newHtml);

  if (!oldHtml) return console.log("NO OLD", { oldHtml, newHtml });

  const diff = diffHtml(oldHtml, newHtml);
  if (!diff) return console.log("NO DIFF", { oldHtml, newHtml });

  console.log("DIFF", diff);

  email({ subject: `Diff for ${url}`, text: diff });
}

View and run this example on Val Town

import { isUp as isUp2 } from "https://esm.town/v/brenton/isUp?v=8";

export const checkSite = () => {
  const isUp = isUp2("https://rodrigotello.me/", 200);
  if (!isUp) {
    console.email(
      "Unexpected status code when checking brntn.me, better go check to see what's happening!",
      "brntn.me is down!"
    );
  }
};