use common var for 'config.yml', standarize on UTF-8

This makes it easy to track all the places that use config.yml, and
hopefully makes things feel cleaner.  This also standardizes all places
where config.yml is written out to use UTF-8 as the file encoding.

This also includes a lot of black code format fixes.

fdroidserver/common.py

@@ -126,6 +126,7 @@ CONFIG_NAMES = (
     RELEASECHANNELS_CONFIG_NAME,
 )
 
+CONFIG_FILE = 'config.yml'
 
 config = None
 options = None
@@ -525,7 +526,7 @@ def config_type_check(path, data):
 def read_config():
     """Read the repository config.
 
-    The config is read from config_file, which is in the current
+    The config is read from config.yml, which is in the current
     directory when any of the repo management commands are used. If
     there is a local metadata file in the git repo, then the config is
     not required, just use defaults.
@@ -546,21 +547,20 @@ def read_config():
         return config
 
     config = {}
-    config_file = 'config.yml'
-    old_config_file = 'config.py'
 
-    if os.path.exists(config_file):
-        logging.debug(_("Reading '{config_file}'").format(config_file=config_file))
-        with open(config_file, encoding='utf-8') as fp:
+    if os.path.exists(CONFIG_FILE):
+        logging.debug(_("Reading '{config_file}'").format(config_file=CONFIG_FILE))
+        with open(CONFIG_FILE, encoding='utf-8') as fp:
             config = yaml.safe_load(fp)
         if not config:
             config = {}
-        config_type_check(config_file, config)
+        config_type_check(CONFIG_FILE, config)
 
+    old_config_file = 'config.py'
     if os.path.exists(old_config_file):
         logging.warning(
             _("""Ignoring deprecated {oldfile}, use {newfile}!""").format(
-                oldfile=old_config_file, newfile=config_file
+                oldfile=old_config_file, newfile=CONFIG_FILE
             )
         )
 
@@ -577,14 +577,13 @@ def read_config():
                                       '-providerArg', 'opensc-fdroid.cfg']
 
     if any(k in config for k in ["keystore", "keystorepass", "keypass"]):
-        if os.path.exists(config_file):
-            f = config_file
-        elif os.path.exists(old_config_file):
-            f = old_config_file
-        st = os.stat(f)
+        st = os.stat(CONFIG_FILE)
         if st.st_mode & stat.S_IRWXG or st.st_mode & stat.S_IRWXO:
-            logging.warning(_("unsafe permissions on '{config_file}' (should be 0600)!")
-                            .format(config_file=f))
+            logging.warning(
+                _("unsafe permissions on '{config_file}' (should be 0600)!").format(
+                    config_file=CONFIG_FILE
+                )
+            )
 
     fill_config_defaults(config)
 
@@ -4191,9 +4190,17 @@ def load_stats_fdroid_signing_key_fingerprints():
         return json.loads(str(f.read('publishsigkeys.json'), 'utf-8'))
 
 
-def write_to_config(thisconfig, key, value=None, config_file=None):
+def write_config_file(config):
+    """Write the provided string to config.yml with the right path and encoding."""
+    Path(CONFIG_FILE).write_text(config, encoding='utf-8')
+
+
+def write_to_config(thisconfig, key, value=None):
     """Write a key/value to the local config.yml.
 
+    The config.yml is defined as YAML 1.2 in UTF-8 encoding on all
+    platforms.
+
     NOTE: only supports writing string variables.
 
     Parameters
@@ -4205,21 +4212,18 @@ def write_to_config(thisconfig, key, value=None, config_file=None):
     value
         optional value to be written, instead of fetched
         from 'thisconfig' dictionary.
+
     """
     if value is None:
         origkey = key + '_orig'
         value = thisconfig[origkey] if origkey in thisconfig else thisconfig[key]
-    if config_file:
-        cfg = config_file
-    else:
-        cfg = 'config.yml'
 
     # load config file, create one if it doesn't exist
-    if not os.path.exists(cfg):
-        open(cfg, 'a').close()
-        logging.info("Creating empty " + cfg)
-    with open(cfg, 'r') as f:
-        lines = f.readlines()
+    if not os.path.exists(CONFIG_FILE):
+        write_config_file('')
+        logging.info(_("Creating empty {config_file}").format(config_file=CONFIG_FILE))
+    with open(CONFIG_FILE) as fp:
+        lines = fp.readlines()
 
     # make sure the file ends with a carraige return
     if len(lines) > 0:
@@ -4233,7 +4237,7 @@ def write_to_config(thisconfig, key, value=None, config_file=None):
     # second instance of this line for this key in the document.
     didRepl = False
     # edit config file
-    with open(cfg, 'w') as f:
+    with open(CONFIG_FILE, 'w', encoding='utf-8') as f:
         for line in lines:
             if pattern.match(line):
                 if not didRepl:

fdroidserver/init.py

@@ -38,13 +38,13 @@ def disable_in_config(key, value):
     """Write a key/value to the local config.yml, then comment it out."""
     import yaml
 
-    with open('config.yml') as f:
-        data = f.read()
+    with open(common.CONFIG_FILE) as fp:
+        data = fp.read()
     pattern = r'\n[\s#]*' + key + r':.*'
     repl = '\n#' + yaml.dump({key: value}, default_flow_style=False)
     data = re.sub(pattern, repl, data)
-    with open('config.yml', 'w') as f:
-        f.writelines(data)
+    with open(common.CONFIG_FILE, 'w') as fp:
+        fp.writelines(data)
 
 
 def main():
@@ -138,24 +138,24 @@ def main():
             _("Android SDK not found at {path}!").format(path=test_config['sdk_path'])
         )
 
-    if not os.path.exists('config.yml'):
+    if not os.path.exists(common.CONFIG_FILE):
         # 'metadata' and 'tmp' are created in fdroid
         if not os.path.exists('repo'):
             os.mkdir('repo')
-        example_config_yml = os.path.join(examplesdir, 'config.yml')
+        example_config_yml = os.path.join(examplesdir, common.CONFIG_FILE)
         if os.path.exists(example_config_yml):
-            shutil.copyfile(example_config_yml, 'config.yml')
+            shutil.copyfile(example_config_yml, common.CONFIG_FILE)
         else:
             from pkg_resources import get_distribution
 
             versionstr = get_distribution('fdroidserver').version
             if not versionstr:
                 versionstr = 'master'
-            with open('config.yml', 'w') as fp:
+            with open(common.CONFIG_FILE, 'w') as fp:
                 fp.write('# see https://gitlab.com/fdroid/fdroidserver/blob/')
                 fp.write(versionstr)
-                fp.write('/examples/config.yml\n')
-        os.chmod('config.yml', 0o0600)
+                fp.write(f'/examples/{common.CONFIG_FILE}\n')
+        os.chmod(common.CONFIG_FILE, 0o0600)
         # If android_home is None, test_config['sdk_path'] will be used and
         # "$ANDROID_HOME" may be used if the env var is set up correctly.
         # If android_home is not None, the path given from the command line

fdroidserver/lint.py

@@ -976,7 +976,7 @@ def main():
     paths = list()
     for arg in options.appid:
         if (
-            arg == 'config.yml'
+            arg == common.CONFIG_FILE
             or Path(arg).parent.name == 'config'
             or Path(arg).parent.parent.name == 'config'  # localized
         ):

fdroidserver/nightly.py

@@ -423,9 +423,9 @@ Last updated: {date}'''.format(repo_git_base=repo_git_base,
             'keydname': DISTINGUISHED_NAME,
             'make_current_version_link': False,
         }
-        with open('config.yml', 'w') as fp:
+        with open(common.CONFIG_FILE, 'w', encoding='utf-8') as fp:
             yaml.dump(config, fp, default_flow_style=False)
-        os.chmod('config.yml', 0o600)
+        os.chmod(common.CONFIG_FILE, 0o600)
         config = common.read_config()
         common.assert_config_keystore(config)