nodemanager/scripts/Utils/ConfigUtil.py

#
# Handler library for Linux IaaS
#
# Copyright 2014 Microsoft Corporation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# Requires Python 2.7+


"""
JSON def:
nodemanager.json
{
	"TrustedCAFile":"/opt/hpcnodemanager/certs/{trustedCAFile}.pem",
	"HeartbeatUri":"https://{0}:40001/api/{hostname}/computenodereported",
	"MetricInstanceIdsUri":"https://{0}:40001/api/{hostname}/getinstanceids",
	"MetricUri":"",
	"RegisterUri":"https://{0}:40001/api/{hostname}/registerrequested",
	"CertificateChainFile":"/opt/hpcnodemanager/certs/{certificateChainFile}.crt",
	"PrivateKeyFile":"/opt/hpcnodemanager/certs/{PrivateKeyFile}.key",
	"ListeningUri":"https://0.0.0.0:40002",
	"NamingServiceUri":[
		"http://{headnode1}:8939/api/fabric/resolve/singleton/",
		"http://{headnode2}:8939/api/fabric/resolve/singleton/",
		"http://{headnode3}:8939/api/fabric/resolve/singleton/"
		],
	"DefaultServiceName":"SchedulerStatefulService",
	"UdpMetricServiceName":"MonitoringStatefulService"
}
"""


import os
import json
import Utils.AgentUtil as agentUtil

ConfigFile = '/opt/hpcnodemanager/nodemanager.json'


class ConfigUtility:
	def __init__(self, log, error):
		self._log = log
		self._error = error
		self.try_parse_config()
		
	def log(self, message):
		self._log('[ConfigUtility]' + message)

	def error(self, message):
		self._error('[ConfigUtility]' + message)

	def try_parse_config(self):
		config = None
		if not os.path.isfile(ConfigFile):
			self.error("Unable to find config file: " + ConfigFile)
			return None
		ctxt = agentUtil.GetFileContents(ConfigFile)
		if ctxt == None :
			self.error("Unable to read " + ConfigFile)
		try:
			config = json.loads(ctxt)
		except:
			self._error('Unable to decode ' + ConfigFile)
			return None
		self._config = config
		return config

	def get_cluster_connectionstring(self):
		headnodes = []
		for uri in self._config["NamingServiceUri"]:
			start = uri.index('//')+2
			uri = uri[start:]
			end = uri.index(':')
			dnsname = uri[:end]
			headnodes.append(dnsname)
		return ','.join(headnodes)