fix duplicated video streaming bug caused by lambda re-use for /tmp f…

…older issue

stack/lambdas/awsdna-download-cctv/app.py

@@ -25,6 +25,13 @@ def lambda_function(event, context):
     print(event)
     channelName = event['pathParameters']['channelName']
 
+    guid = 'cctv_'+channelName+'_'+datetime.datetime.now().strftime("%f")
+    tmpPrefix = '/tmp/'+guid
+
+    rmOutput = subprocess.check_output(['rm', '-rf', 'tmpPrefix'])
+    subprocess.check_output(['mkdir', tmpPrefix])
+    # print('rmOutput:' + rmOutput)
+
     dynamodb = boto3.resource('dynamodb')
     table = dynamodb.Table('channel')
     resp = table.get_item(
@@ -33,9 +40,9 @@ def lambda_function(event, context):
     print(resp['Item']['playback_url'])
     url = resp['Item']['playback_url']
     file = req.get(url, allow_redirects=True)
-    open('/tmp/playlist.m3u8', 'wb').write(file.content)
+    open(tmpPrefix+'/playlist_'+guid+'.m3u8', 'wb').write(file.content)
 
-    with open("/tmp/playlist.m3u8", "r") as f:
+    with open(tmpPrefix+'/playlist_'+guid+'.m3u8', "r") as f:
         for line in f:
             pass
         last_line = line
@@ -45,10 +52,10 @@ def lambda_function(event, context):
     url3 = '/'.join(url.split('/')[0:-1])+'/'+url2
     print('url3:' + url3)
     file2 = req.get(url3, allow_redirects=True)
-    open('/tmp/chunklist.m3u8', 'wb').write(file2.content)
+    open(tmpPrefix+'/chunklist_'+guid+'.m3u8', 'wb').write(file2.content)
 
     tsList = []
-    with open("/tmp/chunklist.m3u8", "r") as f:
+    with open(tmpPrefix+'/chunklist_'+guid+'.m3u8', "r") as f:
         for line in f:
             if line.endswith('.ts\n'):
                 tsList.append(line.split('\n')[0])
@@ -58,7 +65,7 @@ def lambda_function(event, context):
     for file in tsList:
         tsUrl = '/'.join(url.split('/')[0:-1])+'/'+file
         raw = req.get(tsUrl, allow_redirects=True)
-        open('/tmp/'+file, 'wb').write(raw.content)
+        open(tmpPrefix+'/'+guid+file, 'wb').write(raw.content)
         print('tsUrl:', tsUrl)
 
     # logger.log(logging.ERROR, 'Hello SQS and Lambda!')
@@ -88,21 +95,21 @@ def lambda_function(event, context):
     #     s3.download_file('ivs-video-archive-us-east-1',
     #                      f, '/tmp/'+f.split('/')[-1])
 
-    filePath = "/tmp"
+    filePath = tmpPrefix
     file_list = sorted(
         [file for file in os.listdir(filePath) if file.endswith(".ts")])
 
     logger.log(logging.ERROR, 'filelist:'+'\n'.join(file_list))
 
-    with open("/tmp/file_list.txt", "w+") as f:
+    with open(tmpPrefix+'/file_list_'+guid+'.txt', "w+") as f:
         for file in file_list:
             f.write("file '{}'\n".format(file))
 
-    os.chdir('/tmp/')
+    os.chdir(tmpPrefix+'/')
     output = subprocess.check_output(
-        ['ffmpeg', '-f', 'concat', '-i', 'file_list.txt', '-c', 'copy', 'cctv.mp4'])
+        ['ffmpeg', '-f', 'concat', '-i', 'file_list_'+guid+'.txt', '-c', 'copy', 'cctv_'+guid+'.mp4'])
     # logger.log(logging.ERROR, 'ffmpeg result: '+output)
-    logger.log(logging.ERROR, '/tmp/* file list: ' +
+    logger.log(logging.ERROR, tmpPrefix+'/* file list: ' +
                ', '.join(sorted(os.listdir(filePath))))
 
     # # download file locally to /tmp retrieve metadata
@@ -131,21 +138,23 @@ def lambda_function(event, context):
 
     # uploaded modified video to Amazon S3 bucket
 
-    mp4Name = 'cctv/'+channelName+'_'+datetime.datetime.now().strftime("%f")+'.mp4'
     try:
-        s3.upload_file('/tmp/cctv.mp4', output_bucket, mp4Name)
+        s3.upload_file(tmpPrefix+'/cctv_'+guid+'.mp4',
+                       output_bucket, 'cctv/'+guid+'.mp4')
     except boto3.exceptions.S3UploadFailedError:
         error_message = 'Lambda role does not have permission to call PutObject for the output S3 bucket.'
         # add_failed(bucket, error_message, failed_records, key)
         # continue
 
-    return {
+    response = {
         'statusCode': 200,
         'body': json.dumps({
-            'playback_url': 'https://d3328b7fefvh0o.cloudfront.net/'+mp4Name
+            'playback_url': 'https://d3328b7fefvh0o.cloudfront.net/cctv/'+guid+'.mp4'
         }),
         'headers': {
             'Content-Type': 'application/json',
             'Access-Control-Allow-Origin': '*',
         }
     }
+    print('RESPONSE: ' + response)
+    return response