Introduce post_hook for filesystem storage

Author: Michael Adler

example.cfg

@@ -58,6 +58,8 @@ collections = ["private", "work"]
 type = filesystem
 path = ~/.calendars/
 fileext = .ics
+# For each new / updated file f, invoke the following script with argument f:
+#post_hook = /usr/local/bin/post_process.sh
 
 [storage bob_calendar_remote]
 type = caldav

tests/storage/test_filesystem.py

@@ -2,6 +2,7 @@
 
 import os
 import sys
+import subprocess
 
 import pytest
 
@@ -66,3 +67,29 @@ def test_case_sensitive_uids(self, s, get_item):
             items = list(href for href, etag in s.list())
             assert len(items) == 1
             assert len(set(items)) == 1
+
+    def test_post_hook_inactive(self, tmpdir, monkeypatch):
+
+        def check_call_mock(*args, **kwargs):
+            assert False
+
+        monkeypatch.setattr(subprocess, 'call', check_call_mock)
+
+        s = self.storage_class(str(tmpdir), '.txt', post_hook=None)
+        s.upload(Item(u'UID:a/b/c'))
+
+    def test_post_hook_active(self, tmpdir, monkeypatch):
+
+        calls = []
+        exe = 'foo'
+
+        def check_call_mock(l, *args, **kwargs):
+            calls.append(True)
+            assert len(l) == 2
+            assert l[0] == exe
+
+        monkeypatch.setattr(subprocess, 'call', check_call_mock)
+
+        s = self.storage_class(str(tmpdir), '.txt', post_hook=exe)
+        s.upload(Item(u'UID:a/b/c'))
+        assert calls

vdirsyncer/storage/filesystem.py

@@ -2,6 +2,7 @@
 
 import errno
 import os
+import subprocess
 import uuid
 
 from atomicwrites import atomic_write
@@ -35,13 +36,15 @@ class FilesystemStorage(Storage):
     storage_name = 'filesystem'
     _repr_attributes = ('path',)
 
-    def __init__(self, path, fileext, encoding='utf-8', **kwargs):
+    def __init__(self, path, fileext, encoding='utf-8', post_hook=None,
+                 **kwargs):
         super(FilesystemStorage, self).__init__(**kwargs)
         path = expand_path(path)
         checkdir(path, create=False)
         self.path = path
         self.encoding = encoding
         self.fileext = fileext
+        self.post_hook = post_hook
 
     @classmethod
     def discover(cls, path, **kwargs):
@@ -103,7 +106,7 @@ def upload(self, item):
 
         try:
             href = self._deterministic_href(item)
-            return self._upload_impl(item, href)
+            fpath, etag = self._upload_impl(item, href)
         except OSError as e:
             if e.errno in (
                 errno.ENAMETOOLONG,  # Unix
@@ -112,16 +115,20 @@ def upload(self, item):
                 logger.debug('UID as filename rejected, trying with random '
                              'one.')
                 href = self._random_href()
-                return self._upload_impl(item, href)
+                fpath, etag = self._upload_impl(item, href)
             else:
                 raise
 
+        if self.post_hook:
+            self._run_post_hook(fpath)
+        return href, etag
+
     def _upload_impl(self, item, href):
         fpath = self._get_filepath(href)
         try:
             with atomic_write(fpath, mode='wb', overwrite=False) as f:
                 f.write(item.raw.encode(self.encoding))
-                return href, get_etag_from_fileobject(f)
+                return fpath, get_etag_from_fileobject(f)
         except OSError as e:
             if e.errno == errno.EEXIST:
                 raise exceptions.AlreadyExistingError(item)
@@ -141,7 +148,11 @@ def update(self, href, item, etag):
 
         with atomic_write(fpath, mode='wb', overwrite=True) as f:
             f.write(item.raw.encode(self.encoding))
-            return get_etag_from_fileobject(f)
+            etag = get_etag_from_fileobject(f)
+
+        if self.post_hook:
+            self._run_post_hook(fpath)
+        return etag
 
     def delete(self, href, etag):
         fpath = self._get_filepath(href)
@@ -151,3 +162,11 @@ def delete(self, href, etag):
         if etag != actual_etag:
             raise exceptions.WrongEtagError(etag, actual_etag)
         os.remove(fpath)
+
+    def _run_post_hook(self, fpath):
+        logger.info('Calling post_hook={} with argument={}'.format(
+            self.post_hook, fpath))
+        try:
+            subprocess.call([self.post_hook, fpath])
+        except OSError:
+            logger.exception('Error executing external hook.')