Implement ZFS.get_dataset_info

src/simplezfs/zfs.py

@@ -138,6 +138,18 @@ class ZFS:
             return True
         return False
 
+    def get_dataset_info(self, name: str) -> Dataset:
+        '''
+        Returns basic information about a dataset. To retrieve its properties, see :func:`~ZFS.get_property` and
+        :func:`~ZFS.get_properties`.
+
+        :param name: The name of the dataset in question.
+        :returns: The dataset info.
+        :raises DatasetNotFound: If the dataset does not exist.
+        :raises ValidationError: If the name was invalid.
+        '''
+        raise NotImplementedError(f'{self} has not implemented this function')
+
     def list_datasets(self, *, parent: Union[str, Dataset] = None) -> List[Dataset]:
         '''
         Lists all datasets known to the system. If ``parent`` is set to a pool or dataset name (or a :class:`~zfs.types.Dataset`),

src/simplezfs/zfs_cli.py

@@ -73,6 +73,17 @@ class ZFSCli(ZFS):
             validate_pool_name(name)
         return os.path.exists(os.path.join('/dev/zvol', name))
 
+    def get_dataset_info(self, name: str) -> Dataset:
+        if '/' not in name:
+            validate_pool_name(name)
+        else:
+            validate_dataset_path(name)
+        args = [self.__exe, 'list', '-H', '-t', 'all', name]
+        proc = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE, encoding='utf-8')
+        if proc.returncode != 0 or len(proc.stderr) > 0:
+            self.handle_command_error(proc)
+        return Dataset.from_string(proc.stdout.split('\t')[0].strip())
+
     def list_datasets(self, *, parent: Union[str, Dataset] = None) -> List[Dataset]:
         '''
         :todo: ability to limit to a pool (path validator discards pool-only arguments)

tests/test_zfs.py

@@ -423,6 +423,8 @@ class TestZFS:
 
     def test_notimplemented(self):
         zfs = ZFS()
+        with pytest.raises(NotImplementedError):
+            zfs.get_dataset_info('name')
         with pytest.raises(NotImplementedError):
             zfs.list_datasets()
         with pytest.raises(NotImplementedError):

tests/test_zfs_cli.py

@@ -72,6 +72,38 @@ class TestZFSCli:
 
     ##########################################################################
 
+    @patch('subprocess.run')
+    def test_get_dataset_info_happy_dataset(self, subproc):
+        test_stdout = 'rpool/test	105M	142G	192K	none'
+        subproc.return_value = subprocess.CompletedProcess(args=[], returncode=0, stdout=test_stdout, stderr='')
+
+        zfs = ZFSCli(zfs_exe='/bin/true')
+        data = zfs.get_dataset_info('rpool/test')
+        subproc.assert_called_once()
+        assert ['/bin/true', 'list', '-H', '-t', 'all', 'rpool/test'] == subproc.call_args[0][0]
+        assert data.pool == 'rpool'
+        assert data.parent == 'rpool'
+        assert data.name == 'test'
+        assert data.type == DatasetType.VOLUME
+        assert data.full_path == 'rpool/test'
+
+    @patch('subprocess.run')
+    def test_get_dataset_info_happy_pool(self, subproc):
+        test_stdout = 'rpool	105M	142G	192K	none'
+        subproc.return_value = subprocess.CompletedProcess(args=[], returncode=0, stdout=test_stdout, stderr='')
+
+        zfs = ZFSCli(zfs_exe='/bin/true')
+        data = zfs.get_dataset_info('rpool')
+        subproc.assert_called_once()
+        assert ['/bin/true', 'list', '-H', '-t', 'all', 'rpool'] == subproc.call_args[0][0]
+        assert data.pool == 'rpool'
+        assert data.parent == None
+        assert data.name == 'rpool'
+        assert data.type == DatasetType.VOLUME
+        assert data.full_path == 'rpool'
+
+    ##########################################################################
+
     @patch('subprocess.run')
     def test_list_dataset_noparent_happy(self, subproc):
         test_stdout = '''tank	213G	13.3G	96K	none