From fc1157469830b666e7829327c5e6211c605afdf6 Mon Sep 17 00:00:00 2001
From: Brian Gough <brian.gough@overleaf.com>
Date: Tue, 26 Jan 2021 14:08:29 +0000
Subject: [PATCH 1/2] add uncaughtException handler

---
 services/clsi/app.js                      | 9 +++++++++
 services/clsi/config/settings.defaults.js | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/services/clsi/app.js b/services/clsi/app.js
index 930ebc3e1c..280b869472 100644
--- a/services/clsi/app.js
+++ b/services/clsi/app.js
@@ -339,6 +339,15 @@ const loadHttpPort = Settings.internal.load_balancer_agent.local_port
 
 if (!module.parent) {
   // Called directly
+
+  // handle uncaught exceptions when running in production
+  if (Settings.catchErrors) {
+    process.removeAllListeners('uncaughtException')
+    process.on('uncaughtException', (error) =>
+      logger.error({ err: error }, 'uncaughtException')
+    )
+  }
+
   app.listen(port, host, (error) => {
     if (error) {
       logger.fatal({ error }, `Error starting CLSI on ${host}:${port}`)
diff --git a/services/clsi/config/settings.defaults.js b/services/clsi/config/settings.defaults.js
index 72c3471ba9..a0ad8433aa 100644
--- a/services/clsi/config/settings.defaults.js
+++ b/services/clsi/config/settings.defaults.js
@@ -25,6 +25,8 @@ module.exports = {
   processLifespanLimitMs:
     parseInt(process.env.PROCESS_LIFE_SPAN_LIMIT_MS) || 60 * 60 * 24 * 1000 * 2,
 
+  catchErrors: process.env.CATCH_ERRORS === 'true',
+
   path: {
     compilesDir: Path.resolve(__dirname, '../compiles'),
     outputDir: Path.resolve(__dirname, '../output'),

From f0b4f1238b4c608a0754ee9c36ce2df7f6e2bb80 Mon Sep 17 00:00:00 2001
From: Brian Gough <brian.gough@overleaf.com>
Date: Tue, 26 Jan 2021 16:35:39 +0000
Subject: [PATCH 2/2] provide a /oops-internal endpoint for testing
 uncaughtExceptions

---
 services/clsi/app.js | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/services/clsi/app.js b/services/clsi/app.js
index 280b869472..aee8d44832 100644
--- a/services/clsi/app.js
+++ b/services/clsi/app.js
@@ -213,6 +213,12 @@ app.get('/oops', function (req, res, next) {
   return res.send('error\n')
 })
 
+app.get('/oops-internal', function (req, res, next) {
+  setTimeout(function () {
+    throw new Error('Test error')
+  }, 1)
+})
+
 app.get('/status', (req, res, next) => res.send('CLSI is alive\n'))
 
 Settings.processTooOld = false