rouge: Add support for resizing raw images

docs/conf.py

@@ -21,7 +21,7 @@
 author = 'EPAM Systems'
 
 # The full version, including alpha/beta/rc tags
-release = 'v0.26'
+release = 'v0.27'
 
 # -- General configuration ---------------------------------------------------
 

docs/rouge.rst

@@ -218,15 +218,21 @@ partition (which is described below).
 
    type: raw_image # defines raw image block
    size: 400 MiB
+   resize: false
    image_path: "some/path/rootfs.ext4"
 
 :code:`image_path` is mandatory. This is a file to be included into
 resulting image.
 
 :code:`size` is optional. If it is omitted, `rouge` will use size of
 file. If provided :code:`size` is smaller than file size, `rouge` will
-stop with an error. Thus, you can create block that is bigger than
-file, but not smaller.
+stop with an error. If provided :code:`size` is bigger than file size,
+`rouge` will try to resize the file to match :code:`size`.
+
+:code:`resize` is optional. If set to :code:`false`, it will prevent
+`rouge` from resizing the image to the size of the block. This is
+useful when you want to include a file that is smaller than the block
+and leave the rest of the block empty.
 
 Android Sparse Image Block
 ^^^^^^^^^^^^^^^^^^^^^^^^^^

moulin/rouge/block_entry.py

@@ -9,6 +9,7 @@
 import shutil
 import logging
 import itertools
+import subprocess
 from typing import List, Tuple, NamedTuple, cast
 from tempfile import NamedTemporaryFile, TemporaryDirectory
 
@@ -129,12 +130,14 @@ def __init__(self, node: YamlValue, **kwargs):
         self._node = node
         self._fname = self._node["image_path"].as_str
         self._size = 0
+        self._resize = True
 
     def _complete_init(self):
         mark = self._node["image_path"].mark
         if not os.path.exists(self._fname):
             raise YAMLProcessingError(f"Can't find file '{self._fname}'", mark)
         fsize = os.path.getsize(self._fname)
+        self._resize = self._node.get("resize", True).as_bool
         size_node = self._node.get("size", None)
         if size_node:
             self._size = _parse_size(size_node)
@@ -154,7 +157,29 @@ def size(self) -> int:
     def write(self, fp, offset):
         if not self._size:
             self._complete_init()
-        ext_utils.dd(self._fname, fp, offset)
+
+        fsize = os.path.getsize(self._fname)
+
+        if self._resize and fsize < self._size:
+            # Not using default /tmp to prevent filling ram with huge images
+            with TemporaryDirectory(dir=".") as tmpd:
+                shutil.copy(self._fname, tmpd)
+                with open(os.path.join(tmpd, os.path.basename(self._fname)), "rb+") as data:
+                    data.truncate(self._size)
+                try:
+                    ext_utils.resize2fs(os.path.join(tmpd, os.path.basename(self._fname)))
+                except subprocess.CalledProcessError as e:
+                    log.error(
+                        """Failed to resize %s partition.
+        Right now we support resizing for EXT{2,3,4} partitions only.
+        If you don't really want to resize it, please remove 'size' parameter or set 'resize' to false.
+        If you want to resize some other type of partitions - please create a PR or notify us at least.""",
+                        self._fname)
+                    raise e
+
+                ext_utils.dd(os.path.join(tmpd, os.path.basename(self._fname)), fp, offset)
+        else:
+            ext_utils.dd(self._fname, fp, offset)
 
     def get_deps(self) -> List[str]:
         "Return list of dependencies needed to build this block"

moulin/rouge/ext_utils.py

@@ -93,3 +93,13 @@ def mmd(img: BinaryIO, folders: list):
     args.extend(folders)
 
     _run_cmd(args)
+
+
+def resize2fs(img: str, size: Optional[int] = None):
+    "Resize fs image to the given size"
+    args = ["resize2fs", img]
+
+    if size:
+        args.append(str(size))
+
+    _run_cmd(args)

setup.py

@@ -7,7 +7,7 @@
 
 SETUP_ARGS: Dict[str, Any] = dict(
     name='moulin',  # Required
-    version='0.26',  # Required
+    version='0.27',  # Required
     description='Meta-build system',  # Required
     long_description=long_description,
     long_description_content_type="text/markdown",