Replace get_untar_dir with ImageLayer method

This is work towards tern-tools#948

This commit replaces all instances of the old rootfs get_untar_dir
function with the ImageLayer method get_untar_dir. We also remove
an unused function in passthrough.py that uses layer tar files.

Signed-off-by: Nisha K <[email protected]>

tern/analyze/common.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (c) 2017-2020 VMware, Inc. All Rights Reserved.
+# Copyright (c) 2017-2021 VMware, Inc. All Rights Reserved.
 # SPDX-License-Identifier: BSD-2-Clause
 
 '''
@@ -18,7 +18,6 @@
 from tern.utils import cache
 from tern.utils import constants
 from tern.utils import general
-from tern.utils import rootfs
 from debian_inspector import debcon
 from debian_inspector import copyright as debut_copyright
 
@@ -152,7 +151,7 @@ def save_to_cache(image):
 
 def is_empty_layer(layer):
     '''Return True if the given image layer is empty'''
-    cwd = rootfs.get_untar_dir(layer.tar_file)
+    cwd = layer.get_untar_dir()
     if len(os.listdir(cwd)) == 0:
         return True
     return False

tern/analyze/default/container/multi_layer.py

@@ -41,7 +41,7 @@ def apply_layers(image_obj, top_layer):
     """Apply image diff layers without using a kernel snapshot driver"""
     # All merging happens in the merge directory
     target = os.path.join(rootfs.get_working_dir(), constants.mergedir)
-    layer_dir = rootfs.get_untar_dir(image_obj.layers[top_layer].tar_file)
+    layer_dir = image_obj.layers[top_layer].get_untar_dir()
     layer_contents = layer_dir + '/*'
     # Account for whiteout files
     for fd in image_obj.layers[top_layer].files:

tern/analyze/default/container/single_layer.py

@@ -62,7 +62,7 @@ def find_os_release(host_path):
 def get_os_release(base_layer):
     """Assuming that the layer tarball is untarred are ready to be inspected,
     get the OS information from the os-release file"""
-    return find_os_release(rootfs.get_untar_dir(base_layer.tar_file))
+    return find_os_release(base_layer.get_untar_dir())
 
 
 def get_os_style(image_layer, binary):

tern/analyze/default/default_common.py

@@ -44,7 +44,7 @@ def find_shell(fspath):
 def get_shell(layer):
     '''Find the shell if any on the layer filesystem. Assume that the layer
     has already been unpacked. If there is no shell, return an empty string'''
-    cwd = rootfs.get_untar_dir(layer.tar_file)
+    cwd = layer.get_untar_dir()
     return find_shell(cwd)
 
 
@@ -54,7 +54,7 @@ def get_base_bin(first_layer):
     image and looking for known binaries there. Assume that the layer has
     already been unpacked with the filesystem'''
     binary = ''
-    cwd = rootfs.get_untar_dir(first_layer.tar_file)
+    cwd = first_layer.get_untar_dir()
     for key, value in command_lib.command_lib['base'].items():
         for path in value['path']:
             if os.path.exists(os.path.join(cwd, path)):

tern/analyze/passthrough.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 #
-# Copyright (c) 2019-2020 VMware, Inc. All Rights Reserved.
+# Copyright (c) 2019-2021 VMware, Inc. All Rights Reserved.
 # SPDX-License-Identifier: BSD-2-Clause
 
 """
@@ -9,7 +9,6 @@
 
 
 import logging
-import os
 import shutil
 from stevedore import driver
 from stevedore.exception import NoMatches
@@ -46,18 +45,7 @@ def get_filesystem_command(layer_obj, command):
     # is the last token in the command. So the most straightforward way
     # to perform this operation is to append the target directory
     cmd_list = get_exec_command(command)
-    cmd_list.append(rootfs.get_untar_dir(layer_obj.tar_file))
-    return cmd_list
-
-
-def get_file_command(layer_tar_file, layer_file, command):
-    '''Given an ImageLayer object's tar_file property and a FileData object
-    from that layer, along with the command, return the command in list form
-    with the target file appended at the end'''
-    cmd_list = get_exec_command(command)
-    file_path = os.path.join(
-        rootfs.get_untar_dir(layer_tar_file), layer_file.path)
-    cmd_list.append(file_path)
+    cmd_list.append(layer_obj.get_untar_dir())
     return cmd_list
 
 

tern/prep.py

@@ -54,7 +54,7 @@ def teardown(keep=False):
 def clean_image_tars(image_obj):
     """Given an image object, clean up all the image layer contents"""
     for layer in image_obj.layers:
-        fspath = rootfs.get_untar_dir(layer.tar_file)
+        fspath = layer.get_untar_dir()
         if os.path.exists(fspath):
             rootfs.root_command(rootfs.remove, fspath)
 

tern/report/report.py

@@ -30,7 +30,7 @@ def write_report(report, args):
 def clean_image_tars(image_obj):
     '''Clean up untar directories'''
     for layer in image_obj.layers:
-        fspath = rootfs.get_untar_dir(layer.tar_file)
+        fspath = layer.get_untar_dir()
         if os.path.exists(fspath):
             rootfs.root_command(rootfs.remove, fspath)