expose additional configuration files to CLI

This adds the --add-config-file, --add-email-overrides-file options and
as a side effect allows to specify any number of either which will be
applied in order to the respective configuration objects.

Signed-off-by: Nils Philippsen <nils@redhat.com>

distgit_bugzilla_sync/config.py

@@ -17,6 +17,7 @@
 
 import copy
 import os
+from typing import Optional, Sequence
 
 import toml
 
@@ -84,12 +85,18 @@ class ConfigDict(dict):
                 self[k] = v
 
 
-def load_configuration(addl_config_file=None, addl_email_overrides_file=None):
+def load_configuration(addl_config_files: Optional[Sequence[str]] = None,
+                       addl_email_overrides_files: Optional[Sequence[str]] = None):
     """Load stored configuration.
 
     This function loads default, system-wide, and if specified, additional
     configuration files into the `config` and `email_overrides`
     dictionaries."""
+    if addl_config_files is None:
+        addl_config_files = ()
+    if addl_email_overrides_files is None:
+        addl_email_overrides_files = ()
+
     # Load default files.
     try:
         default_config = toml.load(config_files['default']['configuration'])
@@ -117,25 +124,23 @@ def load_configuration(addl_config_file=None, addl_email_overrides_file=None):
         system_email_overrides = {}
 
     # Load additional files (say, specified on the command line), if any.
-    if addl_config_file:
+    addl_config = ConfigDict()
+    for addl_config_file in addl_config_files:
         try:
-            addl_config = toml.load(addl_config_file)
+            addl_config.update(toml.load(addl_config_file))
         except FileNotFoundError as e:
             raise RuntimeError(
                 f"Additional configuration file {addl_config_file} not found."
             ) from e
-    else:
-        addl_config = {}
 
-    if addl_email_overrides_file:
+    addl_email_overrides = ConfigDict()
+    for addl_email_overrides_file in addl_email_overrides_files:
         try:
-            addl_email_overrides = toml.load(addl_email_overrides_file)
+            addl_email_overrides.update(toml.load(addl_email_overrides_file))
         except FileNotFoundError as e:
             raise RuntimeError(
                 f"Additional email overrides file {addl_email_overrides_file} not found."
             ) from e
-    else:
-        addl_email_overrides = {}
 
     config.clear()
     config.update(default_config)

distgit_bugzilla_sync/script.py

@@ -486,6 +486,12 @@ class DistgitBugzillaSync:
             '--env', dest='env',
             help='Run the script for a specific environment, overrides the one '
             'set in the configuration file')
+        parser.add_argument('--add-config-file', metavar='CONFIG_FILE',
+                            dest='addl_config_files', action='append',
+                            help="File(s) from which to read overriding configuration")
+        parser.add_argument('--add-email-overrides-file', metavar='EMAIL_OVERRIDES_FILE',
+                            dest='addl_email_overrides_files', action='append',
+                            help="File(s) from which to read additional email overrides")
 
         self.args = parser.parse_args()
 
@@ -615,7 +621,8 @@ class DistgitBugzillaSync:
 
         self.get_cli_arguments()
 
-        load_configuration()
+        load_configuration(addl_config_files=self.args.addl_config_files,
+                           addl_email_overrides_files=self.args.addl_email_overrides_files)
         self.config = config
 
         envname = self.config['environment']