Delivery rework

Clean up destination code and add some functionality

• Split the destinations into separate files
• New DestinationTempFile for writing tempfiles into the destination which eventually get added
• All of the close() methods are now streaming
• Implemented ChecksumDecorator, so we get a SHA1SUMS file
• Implemented FetchFile decorator, so we get a rudimentary fetch-all.sh script
• Configured Docker and delivery for local development to have a separate volume mount for serving files

apps/cli/executables/delivery/test/test_api.py

@@ -9,6 +9,11 @@ from delivery.deliverer import LocalDestination
 
 @pytest.fixture
 def dest_dir(tmpdir) -> pathlib.Path:
+    """
+    Generate a destination directory.
+    :param tmpdir:  the tmpdir fixture we depend on
+    :return:  path to the destination directory
+    """
     # generate the destination directory
     dest_dir = pathlib.Path(tmpdir) / "after"
     dest_dir.mkdir()
@@ -17,6 +22,11 @@ def dest_dir(tmpdir) -> pathlib.Path:
 
 @pytest.fixture
 def file_to_deliver(tmpdir) -> pathlib.Path:
+    """
+    Generate some files in a test directory for delivery.
+    :param tmpdir: pytest fixture for the temporary directory
+    :return: a file in the test directory
+    """
     # rewrap the tmpdir as a pathlib.Path instance
     tmpdir = pathlib.Path(tmpdir)