[virt-tools-list] [virt-bootstrap] [PATCH v2 05/14] Make UID/GID mapping reusable

[Radostin Stoyanov]

Move the implementation of UID/GID file ownership mapping for root file
system in the utils module.

This could be used for the ownership mapping for files in qcow2 images.
---
 src/virtBootstrap/utils.py          | 72 ++++++++++++++++++++++++++++++++++++
 src/virtBootstrap/virt_bootstrap.py | 74 +------------------------------------
 2 files changed, 73 insertions(+), 73 deletions(-)

diff --git a/src/virtBootstrap/utils.py b/src/virtBootstrap/utils.py
index 6369127..d1d8734 100644
--- a/src/virtBootstrap/utils.py
+++ b/src/virtBootstrap/utils.py
@@ -447,3 +447,75 @@ def write_progress(prog):
     # Write message to console
     sys.stdout.write(msg)
     sys.stdout.flush()
+
+
+# The implementation for remapping ownership of all files inside a
+# container's rootfs is inspired by the tool uidmapshift:
+#
+# Original author: Serge Hallyn <serge.hallyn at ubuntu.com>
+# Original license: GPLv2
+# http://bazaar.launchpad.net/%7Eserge-hallyn/+junk/nsexec/view/head:/uidmapshift.c
+
+def get_map_id(old_id, opts):
+    """
+    Calculate new map_id.
+    """
+    if old_id >= opts['first'] and old_id < opts['last']:
+        return old_id + opts['offset']
+    return -1
+
+
+def get_mapping_opts(mapping):
+    """
+    Get range options from UID/GID mapping
+    """
+    start = mapping[0] if mapping[0] > -1 else 0
+    target = mapping[1] if mapping[1] > -1 else 0
+    count = mapping[2] if mapping[2] > -1 else 1
+
+    opts = {
+        'first': start,
+        'last': start + count,
+        'offset': target - start
+    }
+    return opts
+
+
+def map_id(path, map_uid, map_gid):
+    """
+    Remapping ownership of all files inside a container's rootfs.
+
+    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 root, _ignore, files in os.walk(os.path.realpath(path)):
+        for name in [root] + files:
+            file_path = os.path.join(root, name)
+
+            stat_info = os.lstat(file_path)
+            old_uid = stat_info.st_uid
+            old_gid = stat_info.st_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
+            os.lchown(file_path, new_uid, new_gid)
+
+
+def mapping_uid_gid(dest, uid_map, gid_map):
+    """
+    Mapping ownership for each uid_map and gid_map.
+    """
+    len_diff = len(uid_map) - len(gid_map)
+
+    if len_diff < 0:
+        uid_map += [None] * abs(len_diff)
+    elif len_diff > 0:
+        gid_map += [None] * len_diff
+
+    for uid, gid in zip(uid_map, gid_map):
+        map_id(dest, uid, gid)
diff --git a/src/virtBootstrap/virt_bootstrap.py b/src/virtBootstrap/virt_bootstrap.py
index c9bf1c8..4459ba0 100755
--- a/src/virtBootstrap/virt_bootstrap.py
+++ b/src/virtBootstrap/virt_bootstrap.py
@@ -69,22 +69,6 @@ def get_source(source_type):
         raise Exception("Invalid image URL scheme: '%s'" % source_type)
 
 
-# The implementation for remapping ownership of all files inside a
-# container's rootfs is inspired by the tool uidmapshift:
-#
-# Original author: Serge Hallyn <serge.hallyn at ubuntu.com>
-# Original license: GPLv2
-# http://bazaar.launchpad.net/%7Eserge-hallyn/+junk/nsexec/view/head:/uidmapshift.c
-
-def get_map_id(old_id, opts):
-    """
-    Calculate new map_id.
-    """
-    if old_id >= opts['first'] and old_id < opts['last']:
-        return old_id + opts['offset']
-    return -1
-
-
 def parse_idmap(idmap):
     """
     Parse user input to 'start', 'target' and 'count' values.
@@ -107,62 +91,6 @@ def parse_idmap(idmap):
         raise ValueError("Invalid UID/GID mapping value: %s" % idmap)
 
 
-def get_mapping_opts(mapping):
-    """
-    Get range options from UID/GID mapping
-    """
-    start = mapping[0] if mapping[0] > -1 else 0
-    target = mapping[1] if mapping[1] > -1 else 0
-    count = mapping[2] if mapping[2] > -1 else 1
-
-    opts = {
-        'first': start,
-        'last': start + count,
-        'offset': target - start
-    }
-    return opts
-
-
-def map_id(path, map_uid, map_gid):
-    """
-    Remapping ownership of all files inside a container's rootfs.
-
-    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 root, _ignore, files in os.walk(os.path.realpath(path)):
-        for name in [root] + files:
-            file_path = os.path.join(root, name)
-
-            stat_info = os.lstat(file_path)
-            old_uid = stat_info.st_uid
-            old_gid = stat_info.st_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
-            os.lchown(file_path, new_uid, new_gid)
-
-
-def mapping_uid_gid(dest, uid_map, gid_map):
-    """
-    Mapping ownership for each uid_map and gid_map.
-    """
-    len_diff = len(uid_map) - len(gid_map)
-
-    if len_diff < 0:
-        uid_map += [None] * abs(len_diff)
-    elif len_diff > 0:
-        gid_map += [None] * len_diff
-
-    for uid, gid in zip(uid_map, gid_map):
-        map_id(dest, uid, gid)
-
-
 # pylint: disable=too-many-arguments
 def bootstrap(uri, dest,
               fmt='dir',
@@ -206,7 +134,7 @@ def bootstrap(uri, dest,
 
     if fmt == "dir" and uid_map or gid_map:
         logger.info("Mapping UID/GID")
-        mapping_uid_gid(dest, uid_map, gid_map)
+        utils.mapping_uid_gid(dest, uid_map, gid_map)
 
 
 def set_logging_conf(loglevel=None):
-- 
2.13.3