Prepare clean Sargo images and validated storage inventories

Keep internal documents out of system images while retaining license notices and package versions. Generate boot mappings from a bounded storage inventory, and allow long SSH diagnostics. Hardware boot qualification remains pending.

tundra/tools/inventory-storage.py

@@ -0,0 +1,55 @@
+#!/usr/bin/env python3
+# SPDX-License-Identifier: MPL-2.0
+"""Inventory an existing Sargo ext4/LVM mount without changing any storage."""
+import argparse
+import hashlib
+import json
+import os
+from pathlib import Path
+import stat
+import subprocess
+
+from storage_layout import mount_table
+
+
+def command(*args):
+    return subprocess.check_output(args, text=True, timeout=15,
+        env={**os.environ, 'PATH': '/usr/sbin:/usr/bin:/sbin:/bin', 'LC_ALL': 'C'}).strip()
+
+
+def inventory(mountpoint):
+    device = Path('/dev/mmcblk0p72')
+    if not stat.S_ISBLK(device.stat().st_mode):
+        raise ValueError('Sargo userdata block device is missing')
+    label = command('blkid', '-s', 'PARTLABEL', '-o', 'value', str(device))
+    if label != 'userdata':
+        raise ValueError('Unexpected partition label')
+    mounted = json.loads(command('findmnt', '--json', '--mountpoint', mountpoint,
+                                 '--output', 'SOURCE,FSTYPE'))['filesystems']
+    if len(mounted) != 1 or mounted[0]['fstype'] != 'ext4':
+        raise ValueError('Expected one existing ext4 mount')
+    source = mounted[0]['source']
+    if not source.startswith('/dev/mapper/'):
+        raise ValueError('Only the existing single-extent LVM layout is supported')
+    table = command('dmsetup', 'table', source)
+    with device.open('rb', buffering=0) as stream:
+        first = stream.read(1048576)
+    if len(first) != 1048576:
+        raise ValueError('Cannot read userdata identity')
+    layout = {
+        'schema': 2, 'device': str(device), 'partitionLabel': label,
+        'filesystem': mounted[0]['fstype'], 'table': table,
+        'backingDevice': Path('/sys/class/block/mmcblk0p72/dev').read_text().strip(),
+        'size': int(command('blockdev', '--getsize64', str(device))),
+        'firstMiBSha256': hashlib.sha256(first).hexdigest(),
+    }
+    mount_table(layout)
+    return layout
+
+
+if __name__ == '__main__':
+    parser = argparse.ArgumentParser(description=__doc__)
+    parser.add_argument('--mountpoint', required=True,
+                        help='Existing root mount, or /reference/installed under Tundra')
+    args = parser.parse_args()
+    print(json.dumps(inventory(args.mountpoint), indent=2))