implement config layering

owrx/config/__init__.py

@@ -1,129 +1,32 @@
-from configparser import ConfigParser
-from owrx.property import PropertyLayer
-import importlib.util
-import os
-import json
-from glob import glob
-from owrx.config.error import ConfigError, ConfigNotFoundException
-from owrx.config.migration import ConfigMigratorVersion1, ConfigMigratorVersion2
-
-import logging
-
-logger = logging.getLogger(__name__)
+from owrx.property import PropertyStack
+from owrx.config.error import ConfigError
+from owrx.config.defaults import defaultConfig
+from owrx.config.dynamic import DynamicConfig
+from owrx.config.classic import ClassicConfig
 
 
-class CoreConfig(object):
-    defaults = {
-        "core": {
-            "data_directory": "/var/lib/openwebrx",
-            "temporary_directory": "/tmp",
-        },
-        "web": {
-            "port": 8073,
-        },
-        "aprs": {
-            "symbols_path": "/usr/share/aprs-symbols/png"
-        }
-    }
+class Config(PropertyStack):
+    sharedConfig = None
 
     def __init__(self):
-        config = ConfigParser()
-        # set up config defaults
-        config.read_dict(CoreConfig.defaults)
-        # check for overrides
-        overrides_dir = "/etc/openwebrx/openwebrx.conf.d"
-        if os.path.exists(overrides_dir) and os.path.isdir(overrides_dir):
-            overrides = glob(overrides_dir + "/*.conf")
-        else:
-            overrides = []
-        # sequence things together
-        config.read(["./openwebrx.conf", "/etc/openwebrx/openwebrx.conf"] + overrides)
-        self.data_directory = config.get("core", "data_directory")
-        CoreConfig.checkDirectory(self.data_directory, "data_directory")
-        self.temporary_directory = config.get("core", "temporary_directory")
-        CoreConfig.checkDirectory(self.temporary_directory, "temporary_directory")
-        self.web_port = config.getint("web", "port")
-        self.aprs_symbols_path = config.get("aprs", "symbols_path")
-
-    @staticmethod
-    def checkDirectory(dir, key):
-        if not os.path.exists(dir):
-            raise ConfigError(key, "{dir} doesn't exist".format(dir=dir))
-        if not os.path.isdir(dir):
-            raise ConfigError(key, "{dir} is not a directory".format(dir=dir))
-        if not os.access(dir, os.W_OK):
-            raise ConfigError(key, "{dir} is not writable".format(dir=dir))
-
-    def get_web_port(self):
-        return self.web_port
-
-    def get_data_directory(self):
-        return self.data_directory
-
-    def get_temporary_directory(self):
-        return self.temporary_directory
-
-    def get_aprs_symbols_path(self):
-        return self.aprs_symbols_path
-
-
-class Config:
-    sharedConfig = None
-    currentVersion = 3
-    migrators = {
-        1: ConfigMigratorVersion1(),
-        2: ConfigMigratorVersion2(),
-    }
-
-    @staticmethod
-    def _loadPythonFile(file):
-        spec = importlib.util.spec_from_file_location("config_webrx", file)
-        cfg = importlib.util.module_from_spec(spec)
-        spec.loader.exec_module(cfg)
-        pm = PropertyLayer()
-        for name, value in cfg.__dict__.items():
-            if name.startswith("__"):
-                continue
-            pm[name] = value
-        return pm
-
-    @staticmethod
-    def _loadJsonFile(file):
-        with open(file, "r") as f:
-            pm = PropertyLayer()
-            for k, v in json.load(f).items():
-                pm[k] = v
-            return pm
-
-    @staticmethod
-    def _getSettingsFile():
-        coreConfig = CoreConfig()
-        return "{data_directory}/settings.json".format(data_directory=coreConfig.get_data_directory())
-
-    @staticmethod
-    def _loadConfig():
-        for file in [Config._getSettingsFile(), "/etc/openwebrx/config_webrx.py", "./config_webrx.py"]:
-            try:
-                if file.endswith(".py"):
-                    return Config._loadPythonFile(file)
-                elif file.endswith(".json"):
-                    return Config._loadJsonFile(file)
-                else:
-                    logger.warning("unsupported file type: %s", file)
-            except FileNotFoundError:
-                pass
-        raise ConfigNotFoundException("no usable config found! please make sure you have a valid configuration file!")
+        super().__init__()
+        self.storableConfig = DynamicConfig()
+        layers = [
+            self.storableConfig,
+            ClassicConfig(),
+            defaultConfig,
+        ]
+        for i, l in enumerate(layers):
+            self.addLayer(i, l)
 
     @staticmethod
     def get():
         if Config.sharedConfig is None:
-            Config.sharedConfig = Config._migrate(Config._loadConfig())
+            Config.sharedConfig = Config()
         return Config.sharedConfig
 
-    @staticmethod
-    def store():
-        with open(Config._getSettingsFile(), "w") as file:
-            json.dump(Config.get().__dict__(), file, indent=4)
+    def store(self):
+        self.storableConfig.store()
 
     @staticmethod
     def validateConfig():
@@ -131,14 +34,6 @@ class Config:
         # just basic loading verification
         Config.get()
 
-    @staticmethod
-    def _migrate(config):
-        version = config["version"] if "version" in config else 1
-        if version == Config.currentVersion:
-            return config
-
-        logger.debug("migrating config from version %i", version)
-        migrators = [Config.migrators[i] for i in range(version, Config.currentVersion)]
-        for migrator in migrators:
-            config = migrator.migrate(config)
-        return config
+    def __setitem__(self, key, value):
+        # in the config, all writes go to the json layer
+        return self.storableConfig.__setitem__(key, value)