Query metadata directly from DynamoDB

cmd/resolver/Makefile

@@ -7,7 +7,7 @@ build:
 deploy: build
 	aws --profile Podsync lambda create-function \
 		--function-name Resolver \
-		--role $(shell aws --profile Podsync iam get-role --role-name AWSLambdaBasicExecutionRole --query 'Role.Arn' --output text) \
+		--role $(shell aws --profile Podsync iam get-role --role-name PodsyncResolverLambdaRole --query 'Role.Arn' --output text) \
 		--runtime python3.7 \
 		--handler function.handler \
 		--zip-file fileb://function.zip \

cmd/resolver/function.py

@@ -1,15 +1,16 @@
 import os
-import requests
 import youtube_dl
-
-METADATA_URL = os.getenv('METADATA_URL', 'http://podsync.net/api/metadata/{feed_id}')
-print('Using metadata URL template: ' + METADATA_URL)
+import boto3
 
 
 class InvalidUsage(Exception):
     pass
 
 
+dynamodb = boto3.resource('dynamodb')
+
+feeds_table = dynamodb.Table(os.getenv('RESOLVER_DYNAMO_FEEDS_TABLE', 'Feeds'))
+
 opts = {
     'quiet': True,
     'no_warnings': True,
@@ -46,22 +47,37 @@ def download(feed_id, video_id):
     if not video_id:
         raise InvalidUsage('Invalid video id')
 
-    # Pull metadata from API server
-    metadata_url = METADATA_URL.format(feed_id=feed_id, video_id=video_id)
-    r = requests.get(url=metadata_url)
-    json = r.json()
+    # Query feed metadata info from DynamoDB
+    item = _get_metadata(feed_id)
 
     # Build URL
-    provider = json['provider']
+    provider = item['provider']
     tpl = url_formats[provider]
     if not tpl:
         raise InvalidUsage('Invalid feed')
     url = tpl.format(video_id)
 
-    redirect_url = _resolve(url, json)
+    redirect_url = _resolve(url, item)
     return redirect_url
 
 
+def _get_metadata(feed_id):
+    response = feeds_table.get_item(
+        Key={'HashID': feed_id},
+        ProjectionExpression='#P,#F,#Q',
+        ExpressionAttributeNames={
+            '#P': 'Provider',
+            '#F': 'Format',
+            '#Q': 'Quality',
+        },
+    )
+
+    item = response['Item']
+
+    # Make dict keys lowercase
+    return dict((k.lower(), v) for k, v in item.items())
+
+
 def _resolve(url, metadata):
     if not url:
         raise InvalidUsage('Invalid URL')

cmd/resolver/function_test.py

@@ -25,3 +25,12 @@ class TestYtdl(unittest.TestCase):
         self.assertIsNotNone(
             ytdl._resolve('https://vimeo.com/275211960', {'format': 'video', 'quality': 'high', 'provider': 'vimeo'})
         )
+
+
+class TestDynamo(unittest.TestCase):
+    def test_metadata(self):
+        item = ytdl._get_metadata('86qZ')
+        self.assertIsNotNone(item)
+        self.assertIsNotNone(item['format'])
+        self.assertIsNotNone(item['quality'])
+        self.assertIsNotNone(item['provider'])

cmd/resolver/requirements.txt

@@ -1,2 +1 @@
-requests==2.19.1
 youtube_dl==2019.03.09