From 737620e2ca7920621275c4cf980e115297d7b2c4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Ond=C5=99ej=20Syn=C3=A1=C4=8Dek?=
 <ondrejsynacek@fastmail.com>
Date: Sat, 12 Dec 2020 13:19:34 +0100
Subject: [PATCH] feature: add endpoint for logging instrumentation

---
 functions/logger.js      |  4 ++--
 lib/app/index.js         |  2 ++
 lib/routes/index.js      |  2 ++
 lib/routes/track.js      | 24 ++++++++++++++++++++++++
 lib/static/app/logger.js | 17 +++++++++++++++++
 5 files changed, 47 insertions(+), 2 deletions(-)
 create mode 100644 lib/routes/track.js

diff --git a/functions/logger.js b/functions/logger.js
index db59880..b3b189e 100644
--- a/functions/logger.js
+++ b/functions/logger.js
@@ -8,9 +8,9 @@ class FirebaseTransport extends Transport {
     this._db = options.db
   }
 
-  log(info, callback) {
+  async log(info, callback) {
     try {
-      this._db.ref(`log-${new Date().getTime()}`).set(info)
+      await this._db.ref(`log-${new Date().getTime()}`).set(info)
       callback(null, info)
       this.emit('logged', info)
     } catch (err) {
diff --git a/lib/app/index.js b/lib/app/index.js
index 4430848..a6413a1 100644
--- a/lib/app/index.js
+++ b/lib/app/index.js
@@ -10,6 +10,7 @@ const {
   notFound,
   download,
   downloadHTML,
+  track,
 } = require('../routes')
 
 const {
@@ -92,6 +93,7 @@ const configureApplication = ({
 
   app.post('/download/html', downloadHTML(appLogger || null))
   app.post('/download', download(appLogger || null))
+  app.post('/track', track(appLogger || null))
  
 
   app.use(genericErrorHandler)
diff --git a/lib/routes/index.js b/lib/routes/index.js
index 30f31ac..3f9b9dd 100644
--- a/lib/routes/index.js
+++ b/lib/routes/index.js
@@ -1,9 +1,11 @@
 const { error, notFound } = require('./error')
 const { download, downloadHTML } = require('./download')
+const { track } = require('./track')
 
 module.exports = {
   error,
   notFound,
   download,
   downloadHTML,
+  track,
 }
diff --git a/lib/routes/track.js b/lib/routes/track.js
new file mode 100644
index 0000000..0399e2a
--- /dev/null
+++ b/lib/routes/track.js
@@ -0,0 +1,24 @@
+const track = (logger) => async (req, res) => {
+  try {
+    if (!logger) {
+      return res.status(501)
+    }
+
+    const { message, service, level, env } = req.body
+
+    await logger.log({
+      message,
+      level,
+      service,
+      env: process.env.NODE_APP || env || 'N/A',
+    })
+
+    res.status(200).send({ status: 'ok' })
+  } catch (err) {
+    next(err)
+  }
+}
+
+module.exports = {
+  track,
+}
diff --git a/lib/static/app/logger.js b/lib/static/app/logger.js
index 95b8775..4ba5ad5 100644
--- a/lib/static/app/logger.js
+++ b/lib/static/app/logger.js
@@ -6,6 +6,23 @@ class Logger {
       'color: grey',
       'color: black'
     )
+
+    this._log({ message, level, service })
+  }
+
+  _log({ message, level, service }) {
+    return new Promise((resolve, reject) => {
+      fetch('/track', {
+        method: 'POST',
+        headers: {
+          'Accept': 'text/html, application/json',
+          'Content-Type': 'application/json',
+        },
+        body: JSON.stringify({ message, level, service, env: 'browser' })
+      })
+        .then(resolve)
+        .catch(reject)
+    })
   }
 }