[virt-tools-list] [virt-bootstrap] [PATCH v2 07/14] Enable UID/GID mapping for qcow2

[Radostin Stoyanov]

Implement UID/GID file ownership mapping for qcow2 images.

The implementation consist of:
    For each layer:
        1. Create qcow2 image with backing chain
        2. Tar-in the content form tarball
        2. Get a list of all members (stored files) of this tarball
        3. For each member get the UID/GID
        4. Apply the new ownership for this member in the qcow2 image
---
 src/virtBootstrap/sources/docker_source.py |  5 ++++-
 src/virtBootstrap/sources/file_source.py   |  6 +++--
 src/virtBootstrap/utils.py                 | 35 +++++++++++++++++++++++++++++-
 src/virtBootstrap/virt_bootstrap.py        |  2 ++
 4 files changed, 44 insertions(+), 4 deletions(-)

diff --git a/src/virtBootstrap/sources/docker_source.py b/src/virtBootstrap/sources/docker_source.py
index 9220e13..0ca3b20 100644
--- a/src/virtBootstrap/sources/docker_source.py
+++ b/src/virtBootstrap/sources/docker_source.py
@@ -58,6 +58,8 @@ class DockerSource(object):
         self.url = self.gen_valid_uri(kwargs['uri'])
         self.username = kwargs['username']
         self.password = kwargs['password']
+        self.uid_map = kwargs['uid_map']
+        self.gid_map = kwargs['gid_map']
         self.output_format = kwargs['fmt']
         self.insecure = kwargs['not_secure']
         self.no_cache = kwargs['no_cache']
@@ -262,7 +264,8 @@ class DockerSource(object):
             elif self.output_format == 'qcow2':
                 self.progress("Extracting container layers into qcow2 images",
                               value=50, logger=logger)
-                utils.Build_QCOW2_Image(self.tar_files, dest, self.progress)
+                utils.Build_QCOW2_Image(self.tar_files, dest, self.progress,
+                                        self.uid_map, self.gid_map)
             else:
                 raise Exception("Unknown format:" + self.output_format)
 
diff --git a/src/virtBootstrap/sources/file_source.py b/src/virtBootstrap/sources/file_source.py
index 87589f6..748181f 100644
--- a/src/virtBootstrap/sources/file_source.py
+++ b/src/virtBootstrap/sources/file_source.py
@@ -44,6 +44,8 @@ class FileSource(object):
         """
         self.path = kwargs['uri'].path
         self.output_format = kwargs['fmt']
+        self.uid_map = kwargs['uid_map']
+        self.gid_map = kwargs['gid_map']
         self.progress = kwargs['progress'].update_progress
 
     def unpack(self, dest):
@@ -60,11 +62,11 @@ class FileSource(object):
             self.progress("Extracting files into destination directory",
                           value=0, logger=logger)
             utils.safe_untar(self.path, dest)
-
         elif self.output_format == 'qcow2':
             self.progress("Extracting files into qcow2 image", value=0,
                           logger=logger)
-            utils.Build_QCOW2_Image([self.path], dest, self.progress)
+            utils.Build_QCOW2_Image([self.path], dest, self.progress,
+                                    self.uid_map, self.gid_map)
         else:
             raise Exception("Unknown format:" + self.output_format)
 
diff --git a/src/virtBootstrap/utils.py b/src/virtBootstrap/utils.py
index cf5becc..c69b5da 100644
--- a/src/virtBootstrap/utils.py
+++ b/src/virtBootstrap/utils.py
@@ -28,6 +28,7 @@ import hashlib
 import json
 import os
 import sys
+import tarfile
 import tempfile
 import logging
 import re
@@ -56,7 +57,7 @@ class Build_QCOW2_Image(object):
     """
     Create qcow2 image with backing chains from list of tar files.
     """
-    def __init__(self, tar_files, dest, progress):
+    def __init__(self, tar_files, dest, progress, uid_map=None, gid_map=None):
         """
         Initialize guestfs
         """
@@ -65,6 +66,8 @@ class Build_QCOW2_Image(object):
         self.tar_files = tar_files
         self.nlayers = len(tar_files)
         self.progress = progress
+        self.uid_map = uid_map
+        self.gid_map = gid_map
         self.fmt = 'qcow2'
         self.qcow2_files = [os.path.join(dest, 'layer-%s.qcow2' % i)
                             for i in range(self.nlayers)]
@@ -100,6 +103,14 @@ class Build_QCOW2_Image(object):
         # from tar file.
         self.g.tar_in(tar_file, '/', get_compression_type(tar_file),
                       xattrs=True, selinux=True, acls=True)
+
+        # UID/GID Mapping
+        if self.uid_map or self.gid_map:
+            tar_members = tarfile.open(tar_file).getmembers()
+            balance_uid_gid_maps(self.uid_map, self.gid_map)
+            for uid, gid in zip(self.uid_map, self.gid_map):
+                self.map_id(tar_members, uid, gid)
+
         # Shutdown guestfs instance to avoid hot-plugging of devices.
         self.g.umount('/')
 
@@ -139,6 +150,28 @@ class Build_QCOW2_Image(object):
             self.tar_in(tar_file, devices[i])
 
 
+    def map_id(self, tar_members, map_uid, map_gid):
+        """
+        Remapping ownership of all files inside image.
+
+        map_gid and map_uid: Contain integers in a list with format:
+            [<start>, <target>, <count>]
+        """
+        if map_uid:
+            uid_opts = get_mapping_opts(map_uid)
+        if map_gid:
+            gid_opts = get_mapping_opts(map_gid)
+
+        for member in tar_members:
+            old_uid = member.uid
+            old_gid = member.gid
+
+            new_uid = get_map_id(old_uid, uid_opts) if map_uid else -1
+            new_gid = get_map_id(old_gid, gid_opts) if map_gid else -1
+            if new_uid != -1 or new_gid != -1:
+                self.g.lchown(new_uid, new_gid, os.path.join('/', member.name))
+
+
 def get_compression_type(tar_file):
     """
     Get compression type of tar file.
diff --git a/src/virtBootstrap/virt_bootstrap.py b/src/virtBootstrap/virt_bootstrap.py
index 4459ba0..54025d2 100755
--- a/src/virtBootstrap/virt_bootstrap.py
+++ b/src/virtBootstrap/virt_bootstrap.py
@@ -124,6 +124,8 @@ def bootstrap(uri, dest,
            fmt=fmt,
            username=username,
            password=password,
+           uid_map=uid_map,
+           gid_map=gid_map,
            not_secure=not_secure,
            no_cache=no_cache,
            progress=prog).unpack(dest)
-- 
2.13.3