Fix presigned URL generation race conditions

backend/server.js

@@ -10,6 +10,7 @@ const mongoUri = process.env.MONGO_URI || 'mongodb://127.0.0.1:27017/default?rep
 // Minio set-up variables
 const minioURI = new URL(process.env.MINIO_URI || 'http://kspace-mugshot:2mSI6HdbJ8@127.0.0.1:9000/kspace-mugshot');
 const minioBucket = minioURI.pathname.substring(1);
+console.info("Using bucket:", minioBucket);
 const historyNumber = parseInt(process.env.HISTORY_AMOUNT) || 1000;
 
 // Stream set-up variables
@@ -44,14 +45,12 @@ async function run() {
       secretKey: minioURI.password
     });
 
-    function wrapEvent(doc) {
+    async function wrapEvent(doc) {
       if (doc && doc.screenshot_count) {
         doc.screenshots = [];
         for (let i = 1; i <= doc.screenshot_count ; i++) {
-          minioClient.presignedUrl('GET', minioBucket, `${doc.camera}/${doc._id}/${i}.jpg`, 60 * 60, (err, presignedUrl) => {
-            if (err) { return console.log(err) };
-            doc.screenshots.push({ url: presignedUrl });
-          })
+          let presignedUrl = await minioClient.presignedUrl('GET', minioBucket, `${doc.camera}/${doc._id}/${i}.jpg`, 60 * 60);
+          doc.screenshots.push({ url: presignedUrl });
         }
       };
       let blob = JSON.stringify(doc);
@@ -62,14 +61,14 @@ async function run() {
     const header = { 'Content-Type': 'text/event-stream', 'Connection': 'keep-alive' };
     response.writeHead(200, "OK", header);
 
-    const historyCursor = collection.find({}).sort({$natural : -1}).limit(historyNumber);
+    const historyCursor = collection.find().sort({$natural:-1}).limit(historyNumber);
 
-    historyCursor.forEach((document) => {
-      response.write(wrapEvent(document));
+    historyCursor.forEach(async (document) => {
+      response.write(await wrapEvent(document));
     })
 
-    changeStream.on("change", data => {
-      response.write(wrapEvent(data.fullDocument));
+    changeStream.on("change", async(data) => {
+      response.write(await wrapEvent(data.fullDocument));
     });
   });
 

docker-compose.yml

@@ -9,17 +9,11 @@ x-common: &common
   ME_CONFIG_MONGODB_ENABLE_ADMIN: 'true'
   ME_CONFIG_MONGODB_SERVER: '127.0.0.1'
   ME_CONFIG_MONGODB_AUTH_DATABASE: admin
-  MONGO_URI: mongodb://127.0.0.1:27017/default?replicaSet=rs0
-  MONGO_COLLECTION: eventlog
-  HISTORY_AMOUNT: 10
   MINIO_ACCESS_KEY: kspace-mugshot
   MINIO_SECRET_KEY: 2mSI6HdbJ8
   MINIO_DEFAULT_BUCKETS: kspace-mugshot:download
-  MINIO_CONSOLE_PORT_NUMBER: 9001
   MINIO_URI: 'https://kspace-mugshot:2mSI6HdbJ8@127.0.0.1:9000/kspace-mugshot'
 
-
-
 services:
 
   mongoexpress:

emitter/emitter.py

@@ -1,3 +1,4 @@
+from datetime import datetime
 from pymongo import MongoClient
 from bson.objectid import ObjectId
 from time import sleep
@@ -7,6 +8,14 @@ MONGO_URI="mongodb://127.0.0.1:27017/default"
 db = MongoClient(MONGO_URI).get_default_database() 
 
 while True:
-    db.eventlog.insert_one({ "timestamp": "...", "event": "motion-detected", "started": "...", "finished": "...", "component": "motion-detect", "camera": "Server room", "action": "event",
-                    })
+    db.eventlog.insert_one({
+        "timestamp": datetime.utcnow(),
+        "event": "motion-detected",
+        "started": "...",
+        "finished": "...",
+        "component": "motion-detect",
+        "camera": "Server room",
+        "action": "event",
+        "screenshot_count": 1
+    })
     sleep(1)