Add image checker to imageutils

Adds a CLI to oslo_utils.imageutils which can be used to validate
images.

Example usages:
$ python -m oslo_utils.imageutils -i ./gpt-image.raw -v
SAFETY_CHECK_PASSED=True
VIRTUAL_SIZE=262144
ACTUAL_SIZE=262144
IMAGE_FORMAT='gpt'
OSLO_UTILS_VERSION='7.4.0.dev1'

$ python -m oslo_utils.imageutils -i ./bad-qed.qed -v
SAFETY_CHECK_PASSED=False
VIRTUAL_SIZE=262144
ACTUAL_SIZE=262144
IMAGE_FORMAT='qed'
OSLO_UTILS_VERSION='7.4.0.dev2'
FAILURE_REASONS='banned: This file format is not allowed'

Change-Id: Ia94fa0431a55ab599ffd7385f2be1b18cf4bb1c4

oslo_utils/imageutils/__main__.py

@@ -0,0 +1,17 @@
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+from oslo_utils.imageutils.cli import main
+
+if __name__ == "__main__":
+    main()

oslo_utils/imageutils/cli.py

@@ -0,0 +1,98 @@
+# All Rights Reserved.
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+import argparse
+import logging
+import os
+import sys
+import textwrap
+
+from oslo_utils.imageutils import format_inspector
+from oslo_utils.version import version_info
+
+
+def main():
+    """Run image security checks and give feedback.
+
+    Runs the image format detector and related security checks against
+    a provided image.
+
+    Usage:
+    python -m oslo_utils.imageutils -i /path/to/image [-v|--verbose]
+
+    Default behavior is to communicate status via exit code:
+      - Exit code of 0 indicates a safe image.
+      - Exit code of 1 indicates an unsafe or missing image.
+
+    If verbose mode is enabled, KEY=VALUE is output for several useful
+    pieces of information about the image and imageutils:
+      - SAFETY_CHECK_PASSED (bool)
+      - VIRTUAL_SIZE (virtual disk size)
+      - ACTUAL_SIZE (actual size of image)
+      - IMAGE_FORMAT (format of image)
+      - OSLO_UTILS_VERSION (version of oslo_utils currently in use)
+      - FAILURE_REASONS (reasons for failure, if failed safety check)
+    """
+    logging.basicConfig(level=logging.CRITICAL)
+    oslo_utils_version = str(version_info)
+    parser = argparse.ArgumentParser(
+        prog='oslo.utils.imageutils',
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+        description=(textwrap.dedent('''\
+        oslo.utils.imageutils image checking program.
+          * Exit code of 0 indicates image passes safety check
+          * Exit code of 1 indicates image fails safety check
+        ''')),
+        epilog=f"Testing using oslo.utils version {oslo_utils_version}")
+    parser.add_argument('-v', '--verbose',
+                        action='store_true',
+                        help=("Print detailed information about the image in "
+                              "KEY=VALUE format. Defaults to no output."))
+    parser.add_argument('-i', '--image',
+                        action='store', required=True, metavar="IMG",
+                        help="Path to an image you wish to inspect.")
+    args = parser.parse_args()
+    image = args.image
+    verbose = args.verbose
+
+    if not os.path.exists(image) or not os.path.isfile(image):
+        print('Image path %s provided does not exist' % image, file=sys.stderr)
+        sys.exit(1)
+
+    inspector = format_inspector.detect_file_format(image)
+    safe = True
+    try:
+        inspector.safety_check()
+    except format_inspector.SafetyCheckFailed as e:
+        safe = False
+        failure_reasons = []
+        for exc in e.failures.items():
+            failure_reasons.append("%s: %s" % (exc[0], exc[1]))
+
+    virtual_size = inspector.virtual_size
+    actual_size = inspector.actual_size
+    fmt = str(inspector)
+
+    if verbose:
+        print(f"SAFETY_CHECK_PASSED={safe}")
+        print(f"VIRTUAL_SIZE={virtual_size}")
+        print(f"ACTUAL_SIZE={actual_size}")
+        print(f"IMAGE_FORMAT=\"{fmt}\"")
+        print(f"OSLO_UTILS_VERSION=\"{oslo_utils_version}\"")
+    if safe:
+        sys.exit(0)
+
+    if verbose:
+        print('FAILURE_REASONS=\'%s\'' % ','.join(failure_reasons))
+
+    sys.exit(1)

oslo_utils/version.py

@@ -0,0 +1,18 @@
+#    Copyright 2016 OpenStack Foundation
+#
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+
+import pbr.version
+
+version_info = pbr.version.VersionInfo('oslo.utils')

releasenotes/notes/imageutils-cli-dd0d1cecbc607725.yaml

@@ -0,0 +1,6 @@
+features:
+  - |
+    Adds a utility CLI module for checking images against the format
+    inspector in oslo_utils.imageutils. After installing oslo.utils, simply
+    run ``python -m oslo_utils.imageutils -h`` for full usage for the new
+    CLI helper.

requirements.txt

@@ -12,3 +12,4 @@ packaging>=20.4 # BSD
 tzdata>=2022.4 # MIT
 PyYAML>=3.13 # MIT
 psutil>=3.2.2 # BST
+pbr>=6.1.0 # Apache-2.0