Add unpacking possibilities to the watcher

docs/source/cli.rst

@@ -19,3 +19,16 @@ The command-line tool can be used by invoking `pytroll-watcher <config-file>`. A
      aliases:
        platform_name:
          npp: Suomi-NPP
+
+Unpacking of the file into it's component and subsequent publishing is achieved by passing the archive format
+in the message config part, for example::
+
+   message_config:
+     subject: /segment/viirs/l1b/
+     atype: dataset
+     archive_format: zip
+     data:
+       sensor: viirs
+     aliases:
+       platform_name:
+         npp: Suomi-NPP

src/pytroll_watchers/publisher.py

@@ -9,6 +9,7 @@
 from posttroll.message import Message
 from posttroll.publisher import create_publisher_from_dict_config
 from trollsift import parse
+from upath import UPath
 
 logger = logging.getLogger(__name__)
 
@@ -25,7 +26,9 @@ def file_publisher_from_generator(generator, publisher_config, message_config):
             (filename, file_metadata).
         publisher_config: The configuration dictionary to pass to the posttroll publishing functions.
         message_config: The information needed to complete the posttroll message generation. Will be amended
-             with the file metadata, and passed directly to posttroll's Message constructor.
+            with the file metadata, and passed directly to posttroll's Message constructor.
+            If it contains "archive_format", it is expected to have the archive type, and the contents of the archive
+            will be published as a "dataset".
 
     Side effect:
         Publishes posttroll messages containing the location of the file with the following fields:
@@ -43,15 +46,19 @@ def file_publisher_from_generator(generator, publisher_config, message_config):
     """  # noqa
     publisher = create_publisher_from_dict_config(publisher_config)
     publisher.start()
+    archive_format = message_config.pop("archive_format", None)
     with closing(publisher):
         for file_item, file_metadata in generator:
             amended_message_config = deepcopy(message_config)
             amended_message_config.setdefault("data", {})
-            amended_message_config["data"]["uri"] = file_item.as_uri()
-            amended_message_config["data"]["uid"] = file_item.name
-            with suppress(AttributeError):
-                amended_message_config["data"]["filesystem"] = json.loads(file_item.fs.to_json())
-                amended_message_config["data"]["path"] = file_item.path
+
+            if archive_format:
+                dataset = [_build_file_location(unpacked_file) for unpacked_file in unpack(file_item, archive_format)]
+                amended_message_config["data"]["dataset"] = dataset
+            else:
+                file_location = _build_file_location(file_item)
+                amended_message_config["data"].update(file_location)
+
             aliases = amended_message_config.pop("aliases", {})
             apply_aliases(aliases, file_metadata)
             amended_message_config["data"].update(file_metadata)
@@ -60,6 +67,25 @@ def file_publisher_from_generator(generator, publisher_config, message_config):
             publisher.send(str(msg))
 
 
+def unpack(path, archive_format):
+    """Unpack the path and yield the extracted filenames."""
+    import fsspec
+    fs = fsspec.get_filesystem_class(archive_format)(fsspec.open(path))
+    files = fs.find("/")
+    for fi in files:
+        yield UPath(fi, protocol=archive_format, target_protocol=path.protocol, fo=path.as_uri())
+
+
+def _build_file_location(file_item):
+    file_location = dict()
+    file_location["uri"] = file_item.as_uri()
+    file_location["uid"] = file_item.name
+    with suppress(AttributeError):
+        file_location["filesystem"] = json.loads(file_item.fs.to_json())
+        file_location["path"] = file_item.path
+    return file_location
+
+
 def apply_aliases(aliases, metadata):
     """Apply aliases to the metadata.
 

tests/test_publisher.py

@@ -0,0 +1,36 @@
+"""Tests for the publisher functionality."""
+
+import os
+from shutil import make_archive
+
+from posttroll.testing import patched_publisher
+from pytroll_watchers.publisher import file_publisher_from_generator
+from upath import UPath
+
+
+def test_unpacking(tmp_path):
+    """Test unpacking the watched file's components to a dataset message."""
+    file1 = tmp_path / "to_zip" / "file1"
+    file2 = tmp_path / "to_zip" / "file2"
+    zip_file = tmp_path / "archived.zip"
+
+    file1.parent.mkdir()
+
+    open(file1, "a").close()
+    open(file2, "a").close()
+
+    make_archive(os.path.splitext(zip_file)[0], "zip", tmp_path / "to_zip")
+
+    path = UPath("file://" + str(zip_file))
+
+    publisher_settings = dict(nameservers=False, port=1979)
+    message_settings = dict(subject="/segment/olci/l2/", atype="dataset", data=dict(sensor="olci"),
+                            archive_format="zip")
+
+    with patched_publisher() as messages:
+        file_publisher_from_generator([[path, dict()]],
+                                      publisher_config=publisher_settings,
+                                      message_config=message_settings)
+
+    assert "zip://file1" in messages[0]
+    assert "zip://file2" in messages[0]