From fabdc94ff696923a5c6d3599a284a20b938a7cf8 Mon Sep 17 00:00:00 2001
From: Alicia Sykes <alicia@omg.lol>
Date: Thu, 29 Jun 2023 23:40:06 +0100
Subject: [PATCH] Adds lambda function for checking response times

---
 netlify.toml                   |  5 ++++
 server/lambda/server-status.js | 51 ++++++++++++++++++++++++++++++++++
 2 files changed, 56 insertions(+)
 create mode 100644 server/lambda/server-status.js

diff --git a/netlify.toml b/netlify.toml
index 2f94baa..b8c33af 100644
--- a/netlify.toml
+++ b/netlify.toml
@@ -65,6 +65,11 @@
   from = "/get-txt"
   to = "/.netlify/functions/get-txt"
   status = 301
+  force = true  
+[[redirects]]
+  from = "/server-status"
+  to = "/.netlify/functions/server-status"
+  status = 301
   force = true
   
 # For router history mode, ensure pages land on index
diff --git a/server/lambda/server-status.js b/server/lambda/server-status.js
new file mode 100644
index 0000000..a8b5e40
--- /dev/null
+++ b/server/lambda/server-status.js
@@ -0,0 +1,51 @@
+const https = require('https');
+const { performance, PerformanceObserver } = require('perf_hooks');
+
+exports.handler = async function(event, context) {
+  const { url } = event.queryStringParameters;
+
+  if (!url) {
+    return {
+      statusCode: 400,
+      body: JSON.stringify({ message: 'You must provide a URL query parameter!' }),
+    };
+  }
+
+  let dnsLookupTime;
+  let responseCode;
+  let startTime = performance.now();
+
+  const obs = new PerformanceObserver((items) => {
+    dnsLookupTime = items.getEntries()[0].duration;
+    performance.clearMarks();
+  });
+
+  obs.observe({ entryTypes: ['measure'] });
+
+  performance.mark('A');
+
+  return new Promise((resolve) => {
+    https.get(url, (res) => {
+      let data = '';
+      responseCode = res.statusCode;
+      res.on('data', (chunk) => {
+        data += chunk;
+      });
+      res.on('end', () => {
+        performance.mark('B');
+        performance.measure('A to B', 'A', 'B');
+        let responseTime = performance.now() - startTime;
+        obs.disconnect();
+        resolve({
+          statusCode: 200,
+          body: JSON.stringify({ isUp: true, dnsLookupTime, responseTime, responseCode }),
+        });
+      });
+    }).on('error', (e) => {
+      resolve({
+        statusCode: 500,
+        body: JSON.stringify({ isUp: false, error: e.message }),
+      });
+    });
+  });
+};