Make patronictl use config.py for loading config_file

config.py is not only loading config_file but also can build
configuration from environment variables.

patroni/ctl.py

@@ -11,11 +11,13 @@ import os
 import psycopg2
 import random
 import requests
+import sys
 import time
 import tzlocal
 import yaml
 
 from click import ClickException
+from patroni.config import Config
 from patroni.dcs import get_dcs as _get_dcs
 from patroni.exceptions import PatroniException
 from patroni.postgresql import parseurl
@@ -56,14 +58,23 @@ def parse_dcs(dcs):
 
 def load_config(path, dcs):
     logging.debug('Loading configuration from file %s', path)
-    config = dict()
+    config = {}
+    old_argv = list(sys.argv)
     try:
-        with open(path, 'rb') as fd:
-            config = yaml.safe_load(fd)
-    except (IOError, yaml.YAMLError):
-        logging.exception('Could not load configuration file')
+        sys.argv[1] = path
+        if Config.PATRONI_CONFIG_VARIABLE not in os.environ:
+            for p in ('PATRONI_RESTAPI_LISTEN', 'PATRONI_POSTGRESQL_DATA_DIR'):
+                if p not in os.environ:
+                    os.environ[p] = '.'
+        config = Config().copy()
+    finally:
+        sys.argv = old_argv
 
-    config.update(parse_dcs(dcs) or parse_dcs(config.get('dcs_api')) or {})
+    dcs = parse_dcs(dcs) or parse_dcs(config.get('dcs_api')) or {}
+    if dcs:
+        for d in DCS_DEFAULTS:
+            config.pop(d, None)
+        config.update(dcs)
 
     return config
 

tests/test_ctl.py

@@ -1,7 +1,7 @@
 import etcd
 import os
-import pytest
-import requests.exceptions
+import requests
+import sys
 import unittest
 
 from click.testing import CliRunner
@@ -19,29 +19,14 @@ CONFIG_FILE_PATH = './test-ctl.yaml'
 
 def test_rw_config():
     runner = CliRunner()
-    config = {'a': 'b'}
     with runner.isolated_filesystem():
-        store_config(config, CONFIG_FILE_PATH + '/dummy')
+        store_config({'etcd': {'host': 'localhost:2379'}}, CONFIG_FILE_PATH + '/dummy')
+        sys.argv = ['patronictl.py', '']
+        load_config(CONFIG_FILE_PATH + '/dummy', None)
+        load_config(CONFIG_FILE_PATH + '/dummy', '0.0.0.0')
         os.remove(CONFIG_FILE_PATH + '/dummy')
         os.rmdir(CONFIG_FILE_PATH)
 
-        with pytest.raises(Exception):
-            result = load_config(CONFIG_FILE_PATH, None)
-            assert 'Could not load configuration file' in result.output
-
-        os.mkdir(CONFIG_FILE_PATH)
-        with pytest.raises(Exception):
-            store_config(config, CONFIG_FILE_PATH)
-
-        os.rmdir(CONFIG_FILE_PATH)
-
-    store_config(config, CONFIG_FILE_PATH)
-    load_config(CONFIG_FILE_PATH, None)
-    load_config(CONFIG_FILE_PATH, '0.0.0.0')
-
-    store_config({'dcs_api': None}, CONFIG_FILE_PATH)
-    load_config(CONFIG_FILE_PATH, None)
-
 
 @patch('patroni.ctl.load_config', Mock(return_value={'etcd': {'host': 'localhost:4001'}}))
 class TestCtl(unittest.TestCase):