files: add file format detection on file commit

* this functionality uses a tool called siegfried
  https://github.com/richardlehane/siegfried

invenio_records_resources/services/files/components/__init__.py

@@ -1,6 +1,7 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2021 CERN.
+# Copyright (C) 2024 TU Wien.
 #
 # Invenio-Records-Resources is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -10,6 +11,7 @@
 
 from .base import FileServiceComponent
 from .content import FileContentComponent
+from .filetype import FileTypeDetectionComponent
 from .metadata import FileMetadataComponent
 from .processor import FileProcessorComponent
 
@@ -18,4 +20,5 @@
     "FileMetadataComponent",
     "FileProcessorComponent",
     "FileServiceComponent",
+    "FileTypeDetectionComponent",
 )

invenio_records_resources/services/files/components/filetype.py

@@ -0,0 +1,21 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (C) 2024 TU Wien.
+#
+# Invenio-Records-Resources is free software; you can redistribute it and/or
+# modify it under the terms of the MIT License; see LICENSE file for more
+# details.
+
+"""Service component for detecting file types."""
+
+from ...uow import TaskOp
+from ..tasks import detect_file_type
+from .base import FileServiceComponent
+
+
+class FileTypeDetectionComponent(FileServiceComponent):
+    """Service component for detecting file types."""
+
+    def commit_file(self, identity, id, file_key, record):
+        """Detect the file format as soon as the file has been committed."""
+        self.uow.register(TaskOp(detect_file_type, str(record.bucket.id), file_key))

invenio_records_resources/services/files/config.py

@@ -2,6 +2,7 @@
 #
 # Copyright (C) 2020-2022 CERN.
 # Copyright (C) 2020 Northwestern University.
+# Copyright (C) 2024 TU Wien.
 #
 # Invenio-Records-Resources is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
@@ -15,6 +16,7 @@
     FileContentComponent,
     FileMetadataComponent,
     FileProcessorComponent,
+    FileTypeDetectionComponent,
 )
 from .links import FileLink
 from .processors import ImageMetadataExtractor
@@ -54,6 +56,7 @@ class FileServiceConfig(ServiceConfig):
         FileMetadataComponent,
         FileContentComponent,
         FileProcessorComponent,
+        FileTypeDetectionComponent,
     ]
 
     file_processors = [

invenio_records_resources/services/files/tasks.py

@@ -1,17 +1,23 @@
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2022 CERN.
+# Copyright (C) 2024 TU Wien.
 #
 # Invenio-Records-Resources is free software; you can redistribute it and/or
 # modify it under the terms of the MIT License; see LICENSE file for more
 # details.
 
 """Files tasks."""
 
+import json
+import subprocess as sp
+
 import requests
 from celery import shared_task
 from flask import current_app
 from invenio_access.permissions import system_identity
+from invenio_db import db
+from invenio_files_rest.models import ObjectVersion, ObjectVersionTag
 
 from ...proxies import current_service_registry
 from ...services.errors import FileKeyNotFoundError
@@ -39,3 +45,57 @@ def fetch_file(service_id, record_id, file_key):
 
     except FileKeyNotFoundError as e:
         current_app.logger.error(e)
+
+
+# TODO update siegfried signatures (`sf -update`) regularly
+@shared_task(ignore_result=True)
+def detect_file_type(bucket_id, file_key):
+    """Detect the format of the file using siegfried."""
+    # TODO maybe we should go through the Records-Resources files API instead?
+    ov = ObjectVersion.get(bucket_id, file_key)
+    if ov.file is None:
+        return
+
+    # TODO the original filename is lost (renamed to 'data'), but sf uses the filename
+    #      for parts of its algorithm; possible solutions:
+    #      * create a temporary alias (link?) to the file and pass that to sf
+    #      * pipe the file's contents into sf via stdin and use the `-name` arg
+
+    # TODO question: could we utilize siegfried's server mode?
+
+    mimetype, pronom_id = None, None
+    try:
+        sf_bin = "sf"
+        # TODO this may only be possible for 'local' storage?
+        sf_output = sp.check_output([sf_bin, "-json", ov.file.uri], text=True)
+        result = json.loads(sf_output)
+
+        for file_info in result.get("files", []):
+            # only consider results for the file in question
+            if file_info.get("filename") != ov.file.uri:
+                continue
+
+            if not file_info.get("errors", None) and file_info.get("matches", []):
+                for match in file_info["matches"]:
+                    if match["ns"] == "pronom":
+                        pronom_id = match["id"]
+
+                        # NOTE: there may be results other than for the "pronom" ns
+                        #       which may actually deliver better matches
+                        #       e.g. for the `sway-vulkan` script, the sf website
+                        #           (https://www.itforarchivists.com/siegfried)
+                        #           reports "plain text file" and no mimetype for PRONOM
+                        #           but "shell script" (and a mimetype) for the
+                        #           "freedesktop.org" ns
+                        if match["mime"]:
+                            mimetype = match["mime"]
+
+    except Exception as e:
+        print(e)
+
+    if mimetype is not None:
+        ov.mimetype = mimetype
+    if pronom_id is not None:
+        ObjectVersionTag.create_or_update(ov, "pronom_id", pronom_id)
+
+    db.session.commit()