feat: collect response metrics from cron locations

.prettierignore

@@ -0,0 +1,3 @@
+# Ignore generated files
+out
+public

CODE_OF_CONDUCT.md

@@ -14,21 +14,21 @@ appearance, race, religion, or sexual identity and orientation.
 Examples of behavior that contributes to creating a positive environment
 include:
 
-* Using welcoming and inclusive language
-* Being respectful of differing viewpoints and experiences
-* Gracefully accepting constructive criticism
-* Focusing on what is best for the community
-* Showing empathy towards other community members
+- Using welcoming and inclusive language
+- Being respectful of differing viewpoints and experiences
+- Gracefully accepting constructive criticism
+- Focusing on what is best for the community
+- Showing empathy towards other community members
 
 Examples of unacceptable behavior by participants include:
 
-* The use of sexualized language or imagery and unwelcome sexual attention or
+- The use of sexualized language or imagery and unwelcome sexual attention or
   advances
-* Trolling, insulting/derogatory comments, and personal or political attacks
-* Public or private harassment
-* Publishing others' private information, such as a physical or electronic
+- Trolling, insulting/derogatory comments, and personal or political attacks
+- Public or private harassment
+- Publishing others' private information, such as a physical or electronic
   address, without explicit permission
-* Other conduct which could reasonably be considered inappropriate in a
+- Other conduct which could reasonably be considered inappropriate in a
   professional setting
 
 ## Our Responsibilities

README.md

@@ -10,15 +10,15 @@ Monitor your websites, showcase status including daily history, and get Slack no
 
 You'll need a [Cloudflare Workers account](https://dash.cloudflare.com/sign-up/workers) with
 
-* A workers domain set up
-* The Workers Bundled subscription \($5/mo\)
-    * [It works with Workers Free!](https://blog.cloudflare.com/workers-kv-free-tier/) Check [more info](#workers-kv-free-tier) on how to run on Workers Free. 
-* Some websites/APIs to watch 🙂
+- A workers domain set up
+- The Workers Bundled subscription \($5/mo\)
+  - [It works with Workers Free!](https://blog.cloudflare.com/workers-kv-free-tier/) Check [more info](#workers-kv-free-tier) on how to run on Workers Free.
+- Some websites/APIs to watch 🙂
 
 Also, prepare the following secrets
 
-* Cloudflare API token with `Edit Cloudflare Workers` permissions
-* Slack incoming webhook \(optional\)
+- Cloudflare API token with `Edit Cloudflare Workers` permissions
+- Slack incoming webhook \(optional\)
 
 ## Getting started
 
@@ -39,6 +39,7 @@ You can either deploy with **Cloudflare Deploy Button** using GitHub Actions or
    - Name: SECRET_SLACK_WEBHOOK_URL (optional)
    - Value: your-slack-webhook-url
    ```
+
 3. Navigate to the **Actions** settings in your repository and enable them
 4. Edit [config.yaml](./config.yaml) to adjust configuration and list all of your websites/APIs you want to monitor
 
@@ -73,32 +74,35 @@ You can either deploy with **Cloudflare Deploy Button** using GitHub Actions or
 5. Push to `main` branch to trigger the deployment
 6. 🎉
 7. _\(optional\)_ Go to [Cloudflare Workers settings](https://dash.cloudflare.com/?to=/workers) and assign custom domain/route
-   * e.g. `status-page.eidam.dev/*` _\(make sure you include `/*` as the Worker also serve static files\)_
+   - e.g. `status-page.eidam.dev/*` _\(make sure you include `/*` as the Worker also serve static files\)_
 8. _\(optional\)_ Edit [wrangler.toml](./wrangler.toml) to adjust Worker settings or CRON Trigger schedule, especially if you are on [Workers Free plan](#workers-kv-free-tier)
 
 ### Deploy on your own
 
 You can clone the repository yourself and use Wrangler CLI to develop/deploy, extra list of things you need to take care of:
 
-* create KV namespace and add the `KV_STATUS_PAGE` binding to [wrangler.toml](./wrangler.toml)
-* create Worker secrets _\(optional\)_
-  * `SECRET_SLACK_WEBHOOK_URL`
+- create KV namespace and add the `KV_STATUS_PAGE` binding to [wrangler.toml](./wrangler.toml)
+- create Worker secrets _\(optional\)_
+  - `SECRET_SLACK_WEBHOOK_URL`
 
 ## Workers KV free tier
+
 The Workers Free plan includes limited KV usage, but the quota is sufficient for 2-minute checks only
-* Change the CRON trigger to 2 minutes interval (`crons = ["*/2 * * * *"]`) in [wrangler.toml](./wrangler.toml)
+
+- Change the CRON trigger to 2 minutes interval (`crons = ["*/2 * * * *"]`) in [wrangler.toml](./wrangler.toml)
 
 ## Known issues
 
-* **Max 25 monitors to watch in case you are using Slack notifications**, due to the limit of subrequests Cloudflare Worker can make \(50\).
+- **Max 25 monitors to watch in case you are using Slack notifications**, due to the limit of subrequests Cloudflare Worker can make \(50\).
 
   The plan is to support up to 49 by sending only one Slack notification per scheduled run.
 
-* **KV replication lag** - You might get Slack notification instantly, however it may take couple of more seconds to see the change on your status page as [Cron Triggers are usually running on underutilized quiet hours machines](https://blog.cloudflare.com/introducing-cron-triggers-for-cloudflare-workers/#how-are-you-able-to-offer-this-feature-at-no-additional-cost).
+- **KV replication lag** - You might get Slack notification instantly, however it may take couple of more seconds to see the change on your status page as [Cron Triggers are usually running on underutilized quiet hours machines](https://blog.cloudflare.com/introducing-cron-triggers-for-cloudflare-workers/#how-are-you-able-to-offer-this-feature-at-no-additional-cost).
 
-* **Initial delay (no data)** - It takes couple of minutes to schedule and run CRON Triggers for the first time
+- **Initial delay (no data)** - It takes couple of minutes to schedule and run CRON Triggers for the first time
 
 ## Future plans
+
 Stay tuned for more features coming in, like leveraging the fact that CRON instances are scheduled around the world during the day
- so we can monitor the response times. However, we will most probably wait for the [Durable Objects](https://blog.cloudflare.com/introducing-workers-durable-objects/) to be in open beta
- as they are better fit to reliably store such info.
+so we can monitor the response times. However, we will most probably wait for the [Durable Objects](https://blog.cloudflare.com/introducing-workers-durable-objects/) to be in open beta
+as they are better fit to reliably store such info.

SUMMARY.md

@@ -1,4 +1,3 @@
 # Table of contents
 
-* [Cloudflare Worker - Status Page](README.md)
-
+- [Cloudflare Worker - Status Page](README.md)

config.yaml

@@ -3,6 +3,7 @@ settings:
   url: 'https://status-page.eidam.dev' # used for Slack messages
   logo: logo-192x192.png # image in ./public/ folder
   daysInHistogram: 90 # number of days you want to display in histogram
+  collectResponseTimes: false # experimental feature, enable only for <5 monitors or on paid plans
 
   allmonitorsOperational: 'All Systems Operational'
   notAllmonitorsOperational: 'Not All Systems Operational'
@@ -11,7 +12,7 @@ settings:
   monitorLabelNoData: 'No data'
   dayInHistogramNoData: 'No data'
   dayInHistogramOperational: 'All good'
-  dayInHistogramNotOperational: 'Some checks failed'
+  dayInHistogramNotOperational: ' incident(s)' # xx incident(s) recorded
 
 monitors:
   - id: workers-cloudflare-com # unique identifier

pages/index.js

@@ -2,7 +2,7 @@ import { Store } from 'laco'
 import { useStore } from 'laco-react'
 import Head from 'flareact/head'
 
-import { getMonitors, useKeyPress, switchTheme } from '../src/functions/helpers'
+import { getKVMonitors, useKeyPress } from '../src/functions/helpers'
 import config from '../config.yaml'
 import MonitorCard from '../src/components/monitorCard'
 import MonitorFilter from '../src/components/monitorFilter'
@@ -24,23 +24,20 @@ const filterByTerm = (term) =>
 
 export async function getEdgeProps() {
   // get KV data
-  const {
-    value: kvMonitors,
-    metadata: kvMonitorsMetadata,
-  } = await getMonitors()
+  const kvMonitors = await getKVMonitors()
 
   return {
     props: {
       config,
-      kvMonitors: kvMonitors || {},
-      kvMonitorsMetadata: kvMonitorsMetadata || {},
+      kvMonitors: kvMonitors ? kvMonitors.monitors : {},
+      kvMonitorsLastUpdate: kvMonitors ? kvMonitors.lastUpdate : {},
     },
     // Revalidate these props once every x seconds
     revalidate: 5,
   }
 }
 
-export default function Index({ config, kvMonitors, kvMonitorsMetadata }) {
+export default function Index({ config, kvMonitors, kvMonitorsLastUpdate }) {
   const state = useStore(MonitorStore)
   const slash = useKeyPress('/')
 
@@ -81,7 +78,7 @@ export default function Index({ config, kvMonitors, kvMonitorsMetadata }) {
             <MonitorFilter active={slash} callback={filterByTerm} />
           </div>
         </div>
-        <MonitorStatusHeader kvMonitorsMetadata={kvMonitorsMetadata} />
+        <MonitorStatusHeader kvMonitorsLastUpdate={kvMonitorsLastUpdate} />
         {state.visible.map((monitor, key) => {
           return (
             <MonitorCard

public/tailwind.css

@@ -58,7 +58,7 @@
 
   .tooltip .content {
     @apply invisible absolute z-50 inline-block;
-    @apply rounded-full py-1 px-2 bg-gray-100 dark:bg-gray-800 shadow;
+    @apply rounded-lg py-1 px-2 bg-gray-100 dark:bg-gray-800 shadow;
     @apply opacity-0 transition-all duration-200 scale-50;
   }
 

src/components/monitorHistogram.js

@@ -16,14 +16,17 @@ export default function MonitorHistogram({ monitorId, kvMonitor }) {
         let bg = ''
         let dayInHistogramLabel = config.settings.dayInHistogramNoData
 
-        // filter all dates before first check, check the rest
+        // filter all dates before first check, then check the rest
         if (kvMonitor && kvMonitor.firstCheck <= dayInHistogram) {
-          if (!kvMonitor.failedDays.includes(dayInHistogram)) {
+          if (
+            kvMonitor.checks.hasOwnProperty(dayInHistogram) &&
+            kvMonitor.checks[dayInHistogram].fails > 0
+          ) {
+            bg = 'yellow'
+            dayInHistogramLabel = `${kvMonitor.checks[dayInHistogram].fails} ${config.settings.dayInHistogramNotOperational}`
+          } else {
             bg = 'green'
             dayInHistogramLabel = config.settings.dayInHistogramOperational
-          } else {
-            bg = 'yellow'
-            dayInHistogramLabel = config.settings.dayInHistogramNotOperational
           }
         }
 
@@ -36,6 +39,15 @@ export default function MonitorHistogram({ monitorId, kvMonitor }) {
               <span className="font-semibold text-sm">
                 {dayInHistogramLabel}
               </span>
+              {kvMonitor.checks.hasOwnProperty(dayInHistogram) &&
+                Object.keys(kvMonitor.checks[dayInHistogram].res).map((key) => {
+                  return (
+                    <>
+                      <br />
+                      {key}: {kvMonitor.checks[dayInHistogram].res[key].a}ms
+                    </>
+                  )
+                })}
             </div>
           </div>
         )

src/components/monitorStatusHeader.js

@@ -7,11 +7,11 @@ const classes = {
     'bg-yellow-200 text-yellow-700 dark:bg-yellow-700 dark:text-yellow-200 border-yellow-300 dark:border-yellow-600',
 }
 
-export default function MonitorStatusHeader({ kvMonitorsMetadata }) {
+export default function MonitorStatusHeader({ kvMonitorsLastUpdate }) {
   let color = 'green'
   let text = config.settings.allmonitorsOperational
 
-  if (!kvMonitorsMetadata.monitorsOperational) {
+  if (!kvMonitorsLastUpdate.allOperational) {
     color = 'yellow'
     text = config.settings.notAllmonitorsOperational
   }
@@ -20,13 +20,11 @@ export default function MonitorStatusHeader({ kvMonitorsMetadata }) {
     <div className={`card mb-4 font-semibold ${classes[color]}`}>
       <div className="flex flex-row justify-between items-center">
         <div>{text}</div>
-        {kvMonitorsMetadata.lastUpdate && typeof window !== 'undefined' && (
+        {kvMonitorsLastUpdate.time && typeof window !== 'undefined' && (
           <div className="text-xs font-light">
             checked{' '}
-            {Math.round(
-              (Date.now() - kvMonitorsMetadata.lastUpdate.time) / 1000,
-            )}{' '}
-            sec ago (from {kvMonitorsMetadata.lastUpdate.loc})
+            {Math.round((Date.now() - kvMonitorsLastUpdate.time) / 1000)} sec
+            ago (from {kvMonitorsLastUpdate.loc})
           </div>
         )}
       </div>

src/components/monitorStatusLabel.js

@@ -12,7 +12,7 @@ export default function MonitorStatusLabel({ kvMonitor }) {
   let text = 'No data'
 
   if (typeof kvMonitor !== 'undefined') {
-    if (kvMonitor.operational) {
+    if (kvMonitor.lastCheck.operational) {
       color = 'green'
       text = config.settings.monitorLabelOperational
     } else {

src/functions/cronTrigger.js

@@ -1,33 +1,40 @@
 import config from '../../config.yaml'
 
-import { setKV, getKVWithMetadata, notifySlack } from './helpers'
+import {
+  notifySlack,
+  getCheckLocation,
+  getKVMonitors,
+  setKVMonitors,
+} from './helpers'
 
 function getDate() {
   return new Date().toISOString().split('T')[0]
 }
 
 export async function processCronTrigger(event) {
+  // Get Worker PoP and save it to monitorsStateMetadata
+  const checkLocation = await getCheckLocation()
+  const checkDay = getDate()
+
   // Get monitors state from KV
-  let {
-    value: monitorsState,
-    metadata: monitorsStateMetadata,
-  } = await getKVWithMetadata('monitors_data', 'json')
+  let monitorsState = await getKVMonitors()
 
   // Create empty state objects if not exists in KV storage yet
   if (!monitorsState) {
-    monitorsState = {}
-  }
-  if (!monitorsStateMetadata) {
-    monitorsStateMetadata = {}
+    monitorsState = { lastUpdate: {}, monitors: {} }
   }
 
   // Reset default all monitors state to true
-  monitorsStateMetadata.monitorsOperational = true
+  monitorsState.lastUpdate.allOperational = true
 
   for (const monitor of config.monitors) {
     // Create default monitor state if does not exist yet
-    if (typeof monitorsState[monitor.id] === 'undefined') {
-      monitorsState[monitor.id] = { failedDays: [] }
+    if (typeof monitorsState.monitors[monitor.id] === 'undefined') {
+      monitorsState.monitors[monitor.id] = {
+        firstCheck: checkDay,
+        lastCheck: {},
+        checks: {},
+      }
     }
 
     console.log(`Checking ${monitor.name} ...`)
@@ -41,52 +48,90 @@ export async function processCronTrigger(event) {
       },
     }
 
+    // Perform a check and measure time
+    const requestStartTime = Date.now()
     const checkResponse = await fetch(monitor.url, init)
+    const requestTime = Math.round(Date.now() - requestStartTime)
+
+    // Determine whether operational and status changed
     const monitorOperational =
       checkResponse.status === (monitor.expectStatus || 200)
+    const monitorStatusChanged =
+      monitorsState.monitors[monitor.id].lastCheck.operational !==
+      monitorOperational
+
+    // Save monitor's last check response status
+    monitorsState.monitors[monitor.id].lastCheck = {
+      status: checkResponse.status,
+      statusText: checkResponse.statusText,
+      operational: monitorOperational,
+    }
 
     // Send Slack message on monitor change
     if (
-      monitorsState[monitor.id].operational !== monitorOperational &&
+      monitorStatusChanged &&
       typeof SECRET_SLACK_WEBHOOK_URL !== 'undefined' &&
       SECRET_SLACK_WEBHOOK_URL !== 'default-gh-action-secret'
     ) {
       event.waitUntil(notifySlack(monitor, monitorOperational))
     }
 
-    monitorsState[monitor.id].operational =
-      checkResponse.status === (monitor.expectStatus || 200)
-    monitorsState[monitor.id].firstCheck =
-      monitorsState[monitor.id].firstCheck || getDate()
-
-    // Set monitorsOperational and push current day to failedDays
-    if (!monitorOperational) {
-      monitorsStateMetadata.monitorsOperational = false
-
-      const failedDay = getDate()
-      if (!monitorsState[monitor.id].failedDays.includes(failedDay)) {
-        console.log('Saving new failed daily status ...')
-        monitorsState[monitor.id].failedDays.push(failedDay)
-      }
+    // make sure checkDay exists in checks in cases when needed
+    if (
+      (config.settings.collectResponseTimes || !monitorOperational) &&
+      !monitorsState.monitors[monitor.id].checks.hasOwnProperty(checkDay)
+    ) {
+      monitorsState.monitors[monitor.id].checks[checkDay] = {
+        fails: 0,
+        res: {},
       }
     }
 
-  // Get Worker PoP and save it to monitorsStateMetadata
-  const res = await fetch('https://cloudflare-dns.com/dns-query', {
-    method: 'OPTIONS',
-  })
-  const loc = res.headers.get('cf-ray').split('-')[1]
-  monitorsStateMetadata.lastUpdate = {
-    loc,
-    time: Date.now(),
-  }
-
-  // Save monitorsState and monitorsStateMetadata to KV storage
-  await setKV(
-    'monitors_data',
-    JSON.stringify(monitorsState),
-    monitorsStateMetadata,
+    if (config.settings.collectResponseTimes && monitorOperational) {
+      // make sure location exists in current checkDay
+      if (
+        !monitorsState.monitors[monitor.id].checks[checkDay].res.hasOwnProperty(
+          checkLocation,
         )
+      ) {
+        monitorsState.monitors[monitor.id].checks[checkDay].res[
+          checkLocation
+        ] = {
+          n: 0,
+          ms: 0,
+          a: 0,
+        }
+      }
+
+      // increment number of checks and sum of ms
+      const no = ++monitorsState.monitors[monitor.id].checks[checkDay].res[
+        checkLocation
+      ].n
+      const ms = (monitorsState.monitors[monitor.id].checks[checkDay].res[
+        checkLocation
+      ].ms += requestTime)
+
+      // save new average ms
+      monitorsState.monitors[monitor.id].checks[checkDay].res[
+        checkLocation
+      ].a = Math.round(ms / no)
+    } else if (!monitorOperational) {
+      // Save allOperational to false
+      monitorsState.lastUpdate.allOperational = false
+
+      // Increment failed checks, only on status change (maybe call it .incidents instead?)
+      if (monitorStatusChanged) {
+        monitorsState.monitors[monitor.id].checks[checkDay].fails++
+      }
+    }
+  }
+
+  // Save last update information
+  monitorsState.lastUpdate.time = Date.now()
+  monitorsState.lastUpdate.loc = checkLocation
+
+  // Save monitorsState to KV storage
+  await setKVMonitors(monitorsState)
 
   return new Response('OK')
 }

src/functions/helpers.js

@@ -1,18 +1,20 @@
 import config from '../../config.yaml'
 import { useEffect, useState } from 'react'
 
-export async function getMonitors() {
-  return await getKVWithMetadata('monitors_data', 'json')
+export async function getKVMonitors() {
+  // trying both to see performance difference
+  return KV_STATUS_PAGE.get('monitors_data', 'json')
+  //return JSON.parse(await KV_STATUS_PAGE.get('monitors_data', 'text'))
+}
+
+export async function setKVMonitors(data) {
+  return setKV('monitors_data', JSON.stringify(data))
 }
 
 export async function setKV(key, value, metadata, expirationTtl) {
   return KV_STATUS_PAGE.put(key, value, { metadata, expirationTtl })
 }
 
-export async function getKVWithMetadata(key, type = 'text') {
-  return KV_STATUS_PAGE.getWithMetadata(key, type)
-}
-
 export async function notifySlack(monitor, operational) {
   const payload = {
     attachments: [
@@ -23,7 +25,8 @@ export async function notifySlack(monitor, operational) {
             type: 'section',
             text: {
               type: 'mrkdwn',
-              text: `Monitor *${monitor.name}* changed status to *${operational
+              text: `Monitor *${monitor.name}* changed status to *${
+                operational
                   ? config.settings.monitorLabelOperational
                   : config.settings.monitorLabelNotOperational
               }*`,
@@ -34,8 +37,10 @@ export async function notifySlack(monitor, operational) {
             elements: [
               {
                 type: 'mrkdwn',
-                text: `${operational ? ':white_check_mark:' : ':x:'} \`${monitor.method ? monitor.method : 'GET'
-                  } ${monitor.url}\` - :eyes: <${config.settings.url
+                text: `${operational ? ':white_check_mark:' : ':x:'} \`${
+                  monitor.method ? monitor.method : 'GET'
+                } ${monitor.url}\` - :eyes: <${
+                  config.settings.url
                 }|Status Page>`,
               },
             ],
@@ -78,3 +83,10 @@ export function useKeyPress(targetKey) {
 
   return keyPressed
 }
+
+export async function getCheckLocation() {
+  const res = await fetch('https://cloudflare-dns.com/dns-query', {
+    method: 'OPTIONS',
+  })
+  return res.headers.get('cf-ray').split('-')[1]
+}