Split client and server code.

server/build_manifest.py

@@ -0,0 +1,90 @@
+#!/usr/bin/python3
+
+import argparse
+import hashlib
+import json
+import os
+import re
+import sys
+import time
+
+
+parser = argparse.ArgumentParser(description='iconograph fetcher')
+parser.add_argument(
+    '--image-dir',
+    dest='image_dir',
+    action='store',
+    required=True)
+parser.add_argument(
+    '--image-type',
+    dest='image_type',
+    action='store',
+    required=True)
+parser.add_argument(
+    '--old-manifest',
+    dest='old_manifest',
+    action='store')
+FLAGS = parser.parse_args()
+
+
+class ManifestBuilder(object):
+
+  _FILE_REGEX = '^%(image_type)s\.(?P<timestamp>\d+)\.iso$'
+  _BUF_SIZE = 2 ** 16
+
+  def __init__(self, image_dir, image_type, old_manifest):
+    self._image_dir = image_dir
+    self._file_regex = re.compile(self._FILE_REGEX % {
+        'image_type': image_type,
+    })
+    self._old_manifest = old_manifest
+
+  def _Rollouts(self):
+    if not self._old_manifest:
+      return {}
+    try:
+      with open(self._old_manifest, 'r') as fh:
+        parsed = json.load(fh)
+        return dict(
+            (image['timestamp'], image['rollout_‱'])
+            for image in parsed['images'])
+    except FileNotFoundError:
+      return {}
+
+  def BuildManifest(self):
+    ret = {
+        'timestamp': int(time.time()),
+        'images': [],
+    }
+    rollouts = self._Rollouts()
+    for filename in os.listdir(self._image_dir):
+      match = self._file_regex.match(filename)
+      if not match:
+        continue
+      timestamp = int(match.group('timestamp'))
+      image = {
+          'timestamp': timestamp,
+          'rollout_‱': rollouts.get(timestamp, 0),
+      }
+      with open(os.path.join(self._image_dir, filename), 'rb') as fh:
+        hash_obj = hashlib.sha256()
+        while True:
+          data = fh.read(self._BUF_SIZE)
+          if not data:
+            break
+          hash_obj.update(data)
+        image['hash'] = hash_obj.hexdigest()
+      ret['images'].append(image)
+    ret['images'].sort(key=lambda x: x['timestamp'], reverse=True)
+    return ret
+
+
+def main():
+  builder = ManifestBuilder(FLAGS.image_dir, FLAGS.image_type, FLAGS.old_manifest)
+  manifest = builder.BuildManifest()
+  json.dump(manifest, sys.stdout, sort_keys=True, indent=4)
+  sys.stdout.write('\n')
+
+
+if __name__ == '__main__':
+  main()