implement config layering

owrx/config/core.py

@@ -0,0 +1,59 @@
+from owrx.config import ConfigError
+from configparser import ConfigParser
+import os
+from glob import glob
+
+
+class CoreConfig(object):
+    defaults = {
+        "core": {
+            "data_directory": "/var/lib/openwebrx",
+            "temporary_directory": "/tmp",
+        },
+        "web": {
+            "port": 8073,
+        },
+        "aprs": {
+            "symbols_path": "/usr/share/aprs-symbols/png"
+        }
+    }
+
+    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