From f2bd502cdc1f3d7b8338b64df272b139dcf02e04 Mon Sep 17 00:00:00 2001
From: Ian Gulliver <flamingcow@gmail.com>
Date: Mon, 9 May 2016 20:31:33 +0000
Subject: [PATCH] Carry volume ID from build_image through ISO to manifest

---
 server/build_image.py    | 22 +++++++++++++++++-----
 server/build_manifest.py | 17 ++++++++++++++++-
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/server/build_image.py b/server/build_image.py
index c954f72..bc03e3b 100755
--- a/server/build_image.py
+++ b/server/build_image.py
@@ -54,6 +54,11 @@ parser.add_argument(
     dest='source_iso',
     action='store',
     required=True)
+parser.add_argument(
+    '--volume-id',
+    dest='volume_id',
+    action='store',
+    required=True)
 FLAGS = parser.parse_args()
 
 
@@ -92,7 +97,7 @@ class ImageBuilder(object):
     'loopback.cfg': 'boot/grub/loopback.cfg',
   }
 
-  def __init__(self, source_iso, image_dir, archive, arch, release, modules, kernel_args):
+  def __init__(self, source_iso, image_dir, archive, arch, release, modules, kernel_args, volume_id=None):
     self._source_iso = source_iso
     self._image_dir = image_dir
     self._archive = archive
@@ -100,6 +105,7 @@ class ImageBuilder(object):
     self._release = release
     self._modules = modules or []
     self._kernel_args = kernel_args or []
+    self._volume_id = volume_id
 
     self._ico_server_path = os.path.dirname(sys.argv[0])
 
@@ -275,10 +281,15 @@ class ImageBuilder(object):
 
   def _CreateISO(self, union_path, timestamp):
     dest_iso = os.path.join(self._image_dir, '%d.iso' % timestamp)
-    self._Exec(
-        'grub-mkrescue',
+    args = [
         '--output=%s' % dest_iso,
-        union_path)
+        '--',
+    ]
+    if self._volume_id:
+      args.extend(['-V', self._volume_id])
+    args.append(union_path)
+
+    self._Exec('grub-mkrescue', *args)
     return dest_iso
 
   def _BuildImage(self):
@@ -333,7 +344,8 @@ def main():
       FLAGS.arch,
       FLAGS.release,
       FLAGS.modules,
-      FLAGS.kernel_args)
+      FLAGS.kernel_args,
+      FLAGS.volume_id)
   builder.BuildImage()
 
 
diff --git a/server/build_manifest.py b/server/build_manifest.py
index fef112d..a058168 100755
--- a/server/build_manifest.py
+++ b/server/build_manifest.py
@@ -5,6 +5,7 @@ import hashlib
 import json
 import os
 import re
+import subprocess
 import sys
 import time
 
@@ -37,6 +38,7 @@ FLAGS = parser.parse_args()
 class ManifestBuilder(object):
 
   _FILE_REGEX = re.compile('^(?P<timestamp>\d+)\.iso$')
+  _VOLUME_ID_REGEX = re.compile(b'^Volume id: (?P<volume_id>.+)$', re.MULTILINE)
   _BUF_SIZE = 2 ** 16
 
   def __init__(self, image_dir, old_manifest):
@@ -55,6 +57,15 @@ class ManifestBuilder(object):
     except FileNotFoundError:
       return {}
 
+  def _GetVolumeID(self, path):
+    isoinfo = subprocess.check_output([
+      'isoinfo',
+      '-d',
+      '-i', path,
+    ])
+    match = self._VOLUME_ID_REGEX.search(isoinfo)
+    return match.group('volume_id').decode('ascii')
+
   def BuildManifest(self):
     ret = {
         'timestamp': int(time.time()),
@@ -77,7 +88,11 @@ class ManifestBuilder(object):
         image.update(old_image)
         continue
 
-      with open(os.path.join(self._image_dir, filename), 'rb') as fh:
+      image_path = os.path.join(self._image_dir, filename)
+
+      image['volume_id'] = self._GetVolumeID(image_path)
+
+      with open(image_path, 'rb') as fh:
         hash_obj = hashlib.sha256()
         while True:
           data = fh.read(self._BUF_SIZE)