Merge branch 's3-querystring-expire' into 'develop'

Add notes on AWS_QUERYSTRING_EXPIRE setting

See merge request !918

deploy/env.prod.sample

@@ -171,3 +171,8 @@ AWS_STORAGE_BUCKET_NAME=
 # name in order to access files. Example:
 #   AWS_S3_REGION_NAME=eu-west-2
 # AWS_S3_REGION_NAME=
+
+# If you are using Amazon S3, use this setting to configure how long generated URLs should stay
+# valid. The default value is 3600 (60 minutes). The maximum accepted value is 604800 (7 days)
+
+# AWS_QUERYSTRING_EXPIRE=
\ No newline at end of file

docs/admin/external-storages.rst

@@ -169,3 +169,16 @@ and ``media-src`` headers and reload nginx.
 .. code-block:: shell
 
     add_header Content-Security-Policy "...img-src 'self' https://<your-s3-URL> data:;...media-src https://<your-s3-URL> 'self' data:";
+
+Broken Images in Audio Player On Page Reload
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+If you are serving media directly from an S3-compatible store, you may find that images 
+in the queue and the player won't load after the page is refreshed. This happens if the 
+generated URL has expired and the authorization is no longer valid. You can extend the expiry time
+using the following setting in your ``.env`` file:
+
+.. code-block:: shell
+
+    # The default value is 3600 (60 mins). The maximum is 604800 (7 days)
+    AWS_QUERYSTRING_EXPIRE=604800