From 25c587e62230f6eb6ff4313819dacbc59d3a71c9 Mon Sep 17 00:00:00 2001
From: Sage Vaillancourt <sagev9000@tutanota.com>
Date: Mon, 29 Aug 2022 07:33:25 -0400
Subject: [PATCH] Kill connected consumers of a cluster when it is deleted.

---
 app.js         | 38 ++++++++++++++++++++++++++------------
 query.js       |  3 ++-
 safely-exit.js |  2 +-
 3 files changed, 29 insertions(+), 14 deletions(-)

diff --git a/app.js b/app.js
index eace751..248d418 100644
--- a/app.js
+++ b/app.js
@@ -95,7 +95,18 @@ router.post('/clusters', async (req, res, _next) => {
 
 router.post('/clusters/delete', async (req, res, _next) => {
   const clusterName = req.body.clusterName
-  // TODO: Disconnect
+  // Kill all consumers connected to this cluster and notify those clients via their websocket
+  consumers.forEach(([{ consumer, cluster }, socket]) => {
+    if (clusters[clusterName] !== cluster) {
+      // TODO This reference equality may not be sufficient?
+      return
+    }
+    killConsumer(consumer)
+    socket.send(JSON.stringify({
+      type: 'cluster_deleted',
+      message: clusterName,
+    }))
+  })
   delete clusters[clusterName]
   delete config.clusters[clusterName]
   await storeConfig(config)
@@ -164,7 +175,7 @@ buildEscape(consumers, clusters)
 wsServer.on('connection', socket => {
   socket.send('CONNECTED')
   socket.on('close', async () => {
-    await killConsumer(consumers.get(socket))
+    await killConsumer(consumers.get(socket).consumer)
     consumers.delete(socket)
   })
 
@@ -173,24 +184,27 @@ wsServer.on('connection', socket => {
 
     if (message.mode === 'kill') {
       console.log('KILLING SOCKET')
-      await killConsumer(consumers.get(socket))
+      await killConsumer(consumers.get(socket).consumer)
       consumers.delete(socket)
       return
     }
     const currentMode = message.mode === 'realTime' ? realTimeSearch : search
     const cluster = clusters[message.cluster]
-    const run = async () => consumers.set(socket, await currentMode({
-      kafka: cluster.kafka,
-      searchCode: message.searchCode,
-      immutable: message.immutable,
-      topic: message.topic,
-      maxItems: message.maxItems,
-      socket
-    }))
+    const run = async () => consumers.set(socket, {
+      consumer: await currentMode({
+        kafka: cluster.kafka,
+        searchCode: message.searchCode,
+        immutable: message.immutable,
+        topic: message.topic,
+        maxItems: message.maxItems,
+        socket
+      }),
+      cluster
+    })
 
     run().catch(async e => {
       console.error('run() error occurred!', e.toString())
-      await killConsumer(consumers.get(socket))
+      await killConsumer(consumers.get(socket).consumer)
       // Try again ONCE on failure
       run().catch(ee => socket.send('ERROR: ' + ee))
     })
diff --git a/query.js b/query.js
index a6d0afd..22abd2a 100644
--- a/query.js
+++ b/query.js
@@ -3,7 +3,8 @@ const buildMatcher = code => new Function('message', 'value', code)
 const deepCopy = obj => JSON.parse(JSON.stringify(obj))
 
 const realTimeMessageSearch = async ({ kafka, topic, onMessage, searchCode, immutable = true }) => {
-  const consumer = kafka.consumer({ groupId: 'sage-testing-group' })
+  // TODO Use a UUID/GUID instead
+  const consumer = kafka.consumer({ groupId: 'sage-testing-group' + Math.random() })
 
   console.log({ topic, onMessage, searchCode, immutable })
   await consumer.connect()
diff --git a/safely-exit.js b/safely-exit.js
index 1658cf1..d08c562 100644
--- a/safely-exit.js
+++ b/safely-exit.js
@@ -4,7 +4,7 @@ const signalTraps = ['SIGTERM', 'SIGINT', 'SIGUSR2']
 const disconnectAll = async (consumers, clusters) => {
   await Promise.all([
     ...Object.values(clusters).map(async cluster => cluster.admin.disconnect()),
-    ...Array.from(consumers.values()).map(async consumer => consumer.disconnect())
+    ...Array.from(consumers.values()).map(async consumer => consumer.consumer.disconnect())
   ])
 }