Implement configuration reader

core/config.py

@@ -0,0 +1,103 @@
+import yaml, glob, os
+import logging
+logging.basicConfig(level=logging.DEBUG, format="%(asctime)s - %(levelname)s - %(message)s")
+
+from util import dict_combine_recursive
+
+class ConfigurationError(Exception):
+	pass
+
+class ConfigurationReader(object):
+	def __init__(self, file_):
+		self.sources = []
+		self.configdata = self.read_config(file_)
+		self.config_includes(self.configdata)
+		
+		self.process_config(self.configdata)
+		
+	def read_config(self, file_):
+		try:
+			# File-like object
+			data = file_.read()
+			self.sources.append(":local:")
+		except AttributeError, e:
+			# Filename
+			f = open(file_, "r")
+			data = f.read()
+			f.close()
+			self.sources.append(file_)
+		
+		return yaml.safe_load(data)
+	
+	def process_config(self, configdata):
+		self.config_identity(configdata)
+		self.config_nodes(configdata)
+		self.config_package_settings(configdata)
+		
+	def config_identity(self, configdata):
+		try:
+			self.uuid = configdata['self']['uuid']
+			logging.debug("Own UUID is %s" % self.uuid)
+		except KeyError, e:
+			raise ConfigurationError("A UUID for the node ('self') must be specified.")
+			
+		try:
+			self.pubkey = configdata['self']['pubkey']
+			logging.debug("Own pubkey is %s" % self.pubkey)
+		except KeyError, e:
+			raise ConfigurationError("You must specify a public key for this node.")
+			
+		try:
+			self.privkey = configdata['self']['privkey']
+			logging.debug("Own privkey is %s" % self.privkey)
+		except KeyError, e:
+			raise ConfigurationError("You must specify a private key for this node.")
+		
+	def config_nodes(self, configdata):
+		try:
+			self.nodes = configdata['nodes']
+		except KeyError, e:
+			self.nodes = {} # Optional
+		
+		for uuid, node in self.nodes.iteritems():
+			if "ip" not in node:
+				raise ConfigurationError("IP is missing for node %s." % uuid)
+			if "port" not in node:
+				raise ConfigurationError("Port is missing for node %s." % uuid)
+			if "pubkey" not in node:
+				raise ConfigurationError("Public key is missing for node %s." % uuid)
+			if "permissions" not in node:
+				node['permissions'] = [] # Optional
+				
+			logging.debug("Node %s : IP %s, port %s, pubkey %s, permissions %s" % (uuid, node["ip"], node["port"], node["pubkey"], "|".join(node["permissions"])))
+			
+	def config_package_settings(self, configdata):
+		try:
+			self.package_settings = configdata['package-settings']
+			
+			for key in self.package_settings:
+				logging.debug("Package settings found for package %s" % key)
+		except KeyError, e:
+			self.package_settings = {} # Optional
+			
+	def config_includes(self, configdata):
+		try:
+			include_list = configdata['include']
+		except KeyError, e:
+			return # Optional
+		
+		try:
+			include_list.append
+		except:
+			include_list = [include_list]
+			
+		for include in include_list:
+			for file_ in glob.iglob(os.path.expanduser(include)):
+				if file_ not in self.sources:
+					self.sources.append(file_)
+					includedata = self.read_config(file_)
+					self.configdata = dict_combine_recursive(self.configdata, includedata)
+					self.config_includes(includedata)
+		
+if __name__ == "__main__":
+	c = ConfigurationReader("test.yaml")

core/util.py

@@ -0,0 +1,11 @@
+def dict_combine_recursive(a, b):
+	# Based on http://stackoverflow.com/a/8725321
+	if a is None: return b
+	if b is None: return a
+	if isinstance(a, list) and isinstance(b, list):
+		return list(set(a + b))
+	elif isinstance(a, dict) and isinstance(b, dict):
+		keys = set(a.iterkeys()) | set(b.iterkeys())
+		return dict((key, dict_combine_recursive(a.get(key), b.get(key))) for key in keys)
+	else:
+		return b