rootfspostcommands.py: Restructure sort_passwd and related functions

This change proposes a restructure of the functions in
rootfspostcommandstests.py to clarify the purpose of each function and
also, make it scalable for other use cases (for example adding support
for removing subid backup files).

The main function of interest here is 'tidy_shadowutils_files' which
brings in the functionality of the old 'sort_passwd' making it clear
that it doesn't only sort the passwd file:
- delete backup files
- it sorts passwd, group and the associated shadow files

The other functions are also renamed for consistency and clarity and
more documentation was added.

Signed-off-by: Andrei Gherzan <andrei.gherzan@huawei.com>
Signed-off-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 43 insertions, 17 deletions

diff --git a/meta/lib/rootfspostcommands.py b/meta/lib/rootfspostcommands.py
index b5a51295e2..e344ae2efc 100644
--- a/meta/lib/rootfspostcommands.py
+++ b/meta/lib/rootfspostcommands.py
@@ -6,13 +6,14 @@
 
 import os
 
-def sort_file(filename, mapping):
+def sort_shadowutils_file(filename, mapping):
     """
     Sorts a passwd or group file based on the numeric ID in the third column.
     If a mapping is given, the name from the first column is mapped via that
     dictionary instead (necessary for /etc/shadow and /etc/gshadow). If not,
     a new mapping is created on the fly and returned.
     """
+
     new_mapping = {}
     with open(filename, 'rb+') as f:
         lines = f.readlines()
@@ -33,30 +34,55 @@ def sort_file(filename, mapping):
         # We overwrite the entire file, i.e. no truncate() necessary.
         f.seek(0)
         f.write(b''.join(lines))
+
     return new_mapping
 
-def remove_backup(filename):
+def sort_shadowutils_files(sysconfdir):
     """
-    Removes the backup file for files like /etc/passwd.
+    Sorts shadow-utils 'passwd' and 'group' files in a rootfs' /etc directory
+    by ID.
     """
-    backup_filename = filename + '-'
-    if os.path.exists(backup_filename):
-        os.unlink(backup_filename)
 
-def sort_passwd(sysconfdir):
-    """
-    Sorts passwd and group files in a rootfs /etc directory by ID.
-    Backup files are sometimes are inconsistent and then cannot be
-    sorted (YOCTO #11043), and more importantly, are not needed in
-    the initial rootfs, so they get deleted.
-    """
     for main, shadow in (('passwd', 'shadow'),
                          ('group', 'gshadow')):
         filename = os.path.join(sysconfdir, main)
-        remove_backup(filename)
         if os.path.exists(filename):
-            mapping = sort_file(filename, None)
+            mapping = sort_shadowutils_file(filename, None)
             filename = os.path.join(sysconfdir, shadow)
-            remove_backup(filename)
             if os.path.exists(filename):
-                 sort_file(filename, mapping)
+                 sort_shadowutils_file(filename, mapping)
+
+def remove_shadowutils_backup_file(filename):
+    """
+    Remove shadow-utils backup file for files like /etc/passwd.
+    """
+
+    backup_filename = filename + '-'
+    if os.path.exists(backup_filename):
+        os.unlink(backup_filename)
+
+def remove_shadowutils_backup_files(sysconfdir):
+    """
+    Remove shadow-utils backup files in a rootfs /etc directory. They are not
+    needed in the initial root filesystem and sorting them can be inconsistent
+    (YOCTO #11043).
+    """
+
+    for filename in (
+            'group',
+            'gshadow',
+            'passwd',
+            'shadow',
+        ):
+        filepath = os.path.join(sysconfdir, filename)
+        remove_shadowutils_backup_file(filepath)
+
+def tidy_shadowutils_files(sysconfdir):
+    """
+    Tidy up shadow-utils files.
+    """
+
+    remove_shadowutils_backup_files(sysconfdir)
+    sort_shadowutils_files(sysconfdir)
+
+    return True