set "accepted formats" for metadata in config.py

For a bit repo like f-droid.org, it makes sense to standardize on a single
format for metadata files.  This adds support for enforcing a single data
format, or a reduced set of data formats.  So f-droid.org would run like
this if it changed to YAML:

  accepted_formats = ['txt', 'yaml']

Then once everything was converted to YAML, it could look like this:

  accepted_formats = ['yaml']

examples/config.py

@@ -213,6 +213,11 @@ carbon_port = 2003
 # --server option on dedicated secure build server hosts.
 build_server_always = False
 
+# By default, fdroid will use YAML and the custom .txt metadata formats.  It
+# is also possible to have metadata in JSON and XML. You can enable your
+# preferred formats by setting them in a list:
+# accepted_formats = ['json', 'txt', 'xml', 'yaml']
+
 # Limit in number of characters that fields can take up
 # Only the fields listed here are supported, defaults shown
 char_limits = {

fdroidserver/common.py

@@ -59,6 +59,7 @@ default_config = {
     'ant': "ant",
     'mvn3': "mvn",
     'gradle': 'gradle',
+    'accepted_formats': ['txt', 'yaml'],
     'sync_from_local_copy_dir': False,
     'per_app_repos': False,
     'make_current_version_link': True,

fdroidserver/metadata.py

@@ -499,23 +499,11 @@ def read_metadata(xref=True):
     # exception. So the original .txt format is parsed first, at least until
     # newer formats stabilize.
 
-    for metadatapath in sorted(glob.glob(os.path.join('metadata', '*.txt'))):
-        appid, appinfo = parse_txt_metadata(apps, metadatapath)
-        check_metadata(appinfo)
-        apps[appid] = appinfo
-
-    for metadatapath in sorted(glob.glob(os.path.join('metadata', '*.json'))):
-        appid, appinfo = parse_json_metadata(apps, metadatapath)
-        check_metadata(appinfo)
-        apps[appid] = appinfo
-
-    for metadatapath in sorted(glob.glob(os.path.join('metadata', '*.xml'))):
-        appid, appinfo = parse_xml_metadata(apps, metadatapath)
-        check_metadata(appinfo)
-        apps[appid] = appinfo
-
-    for metadatapath in sorted(glob.glob(os.path.join('metadata', '*.yaml'))):
-        appid, appinfo = parse_yaml_metadata(apps, metadatapath)
+    for metadatapath in sorted(glob.glob(os.path.join('metadata', '*.txt'))
+                               + glob.glob(os.path.join('metadata', '*.json'))
+                               + glob.glob(os.path.join('metadata', '*.xml'))
+                               + glob.glob(os.path.join('metadata', '*.yaml'))):
+        appid, appinfo = parse_metadata(apps, metadatapath)
         check_metadata(appinfo)
         apps[appid] = appinfo
 
@@ -731,6 +719,29 @@ def _decode_dict(data):
     return rv
 
 
+def parse_metadata(apps, metadatapath):
+    root, ext = os.path.splitext(metadatapath)
+    metadataformat = ext[1:]
+    accepted = common.config['accepted_formats']
+    if metadataformat not in accepted:
+        logging.critical('"' + metadatapath
+                         + '" is not in an accepted format, '
+                         + 'convert to: ' + ', '.join(accepted))
+        sys.exit(1)
+
+    if metadataformat == 'txt':
+        return parse_txt_metadata(apps, metadatapath)
+    elif metadataformat == 'json':
+        return parse_json_metadata(apps, metadatapath)
+    elif metadataformat == 'xml':
+        return parse_xml_metadata(apps, metadatapath)
+    elif metadataformat == 'yaml':
+        return parse_yaml_metadata(apps, metadatapath)
+    else:
+        logging.critical('Unknown metadata format: ' + metadatapath)
+        sys.exit(1)
+
+
 def parse_json_metadata(apps, metadatapath):
 
     appid, thisinfo = get_default_app_info_list(apps, metadatapath)

tests/metadata.TestCase

@@ -29,11 +29,12 @@ class MetadataTest(unittest.TestCase):
 
         self.maxDiff = None
 
-        # these only need to be set to prevent code running on None.  The
-        # values are not used in metadata.py
+        # these need to be set to prevent code running on None, only
+        # 'accepted_formats' is actually used in metadata.py
         config = dict()
         config['sdk_path'] = '/opt/android-sdk'
         config['ndk_paths'] = dict()
+        config['accepted_formats'] = ['json', 'txt', 'xml', 'yaml']
         fdroidserver.common.config = config
 
         apps = fdroidserver.metadata.read_metadata(xref=True)