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# Copyright 2017-present Open Networking Foundation
#
# 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.
import os
import sys
import yaml
import requests
import default
from pykwalify.core import Core as PyKwalify
DEFAULT_CONFIG_FILE = "/opt/xos/xos_config.yaml"
DEFAULT_CONFIG_SCHEMA = 'xos-config-schema.yaml'
INITIALIZED = False
CONFIG_FILE = None
CONFIG = {}
GLOBAL_CONFIG_FILE = DEFAULT_CONFIG_FILE
GLOBAL_CONFIG_SCHEMA = DEFAULT_CONFIG_SCHEMA
GLOBAL_CONFIG = {}
class Config:
"""
XOS Configuration APIs
"""
@staticmethod
def init(config_file=DEFAULT_CONFIG_FILE, config_schema=DEFAULT_CONFIG_SCHEMA):
# make schema relative to this directory
# TODO give the possibility to specify an absolute path
config_schema = Config.get_abs_path(config_schema)
global INITIALIZED
global CONFIG
global CONFIG_FILE
global GLOBAL_CONFIG
global GLOBAL_CONFIG_FILE
global GLOBAL_CONFIG_SCHEMA
# Use same schema for both provided and global config by default
GLOBAL_CONFIG_SCHEMA = config_schema
# the config module can be initialized only one
if INITIALIZED:
raise Exception('[XOS-Config] Module already initialized')
INITIALIZED = True
# if XOS_CONFIG_FILE is defined override the config_file
# FIXME shouldn't this stay in whatever module call this one? and then just pass the file to the init method
if os.environ.get('XOS_CONFIG_FILE'):
config_file = os.environ['XOS_CONFIG_FILE']
# if XOS_CONFIG_SCHEMA is defined override the config_schema
# FIXME shouldn't this stay in whatever module call this one? and then just pass the file to the init method
if os.environ.get('XOS_CONFIG_SCHEMA'):
config_schema = Config.get_abs_path(os.environ['XOS_CONFIG_SCHEMA'])
# allow GLOBAL_CONFIG_* to be overridden by env vars
if os.environ.get('XOS_GLOBAL_CONFIG_FILE'):
GLOBAL_CONFIG_FILE = os.environ['XOS_GLOBAL_CONFIG_FILE']
if os.environ.get('XOS_GLOBAL_CONFIG_SCHEMA'):
GLOBAL_CONFIG_SCHEMA = Config.get_abs_path(os.environ['XOS_GLOBAL_CONFIG_SCHEMA'])
# if a -C parameter is set in the cli override the config_file
# FIXME shouldn't this stay in whatever module call this one? and then just pass the file to the init method
if Config.get_cli_param(sys.argv):
config_schema = Config.get_cli_param(sys.argv)
CONFIG_FILE = config_file
CONFIG = Config.read_config(config_file, config_schema)
# Load global schema
GLOBAL_CONFIG = Config.read_config(GLOBAL_CONFIG_FILE, GLOBAL_CONFIG_SCHEMA, True)
@staticmethod
def get_config_file():
return CONFIG_FILE
@staticmethod
def clear():
global INITIALIZED
INITIALIZED = False
@staticmethod
def get_abs_path(path):
if os.path.isabs(path):
return path
return os.path.dirname(os.path.realpath(__file__)) + '/' + path
@staticmethod
def validate_config_format(config_file, config_schema):
schema = os.path.abspath(config_schema)
c = PyKwalify(source_file=config_file, schema_files=[schema])
c.validate(raise_exception=True)
@staticmethod
def get_cli_param(args):
last = None
for arg in args:
if last == '-C':
return arg
last = arg
@staticmethod
def read_config(config_file, config_schema, ignore_if_not_found=False):
"""
Read the configuration file and return a dictionary
:param config_file: string
:return: dict
"""
if(not os.path.exists(config_file) and ignore_if_not_found):
return {}
if not os.path.exists(config_file):
raise Exception('[XOS-Config] Config file not found at: %s' % config_file)
if not os.path.exists(config_schema):
raise Exception('[XOS-Config] Config schema not found at: %s' % config_schema)
try:
Config.validate_config_format(config_file, config_schema)
except Exception, e:
raise Exception('[XOS-Config] The config format is wrong: %s' % e.msg)
with open(config_file, 'r') as stream:
return yaml.safe_load(stream)
@staticmethod
def get(query):
"""
Read a parameter from the config
:param query: a dot separated selector for configuration options (eg: database.username)
:return: the requested parameter in any format the parameter is specified
"""
global INITIALIZED
global CONFIG
global GLOBAL_CONFIG
if not INITIALIZED:
raise Exception('[XOS-Config] Module has not been initialized')
val = Config.get_param(query, CONFIG)
if not val:
val = Config.get_param(query, GLOBAL_CONFIG)
if not val:
val = Config.get_param(query, default.DEFAULT_VALUES)
if not val:
# TODO if no val return none
# raise Exception('[XOS-Config] Config does not have a value (or a default) parameter %s' % query)
return None
return val
@staticmethod
def get_param(query, config):
"""
Search for a parameter in config's first level, other call get_nested_param
:param query: a dot separated selector for configuration options (eg: database.username)
:param config: the config source to read from (can be the config file or the defaults)
:return: the requested parameter in any format the parameter is specified
"""
keys = query.split('.')
if len(keys) == 1:
key = keys[0]
if not config.has_key(key):
return None
return config[key]
else:
return Config.get_nested_param(keys, config)
@staticmethod
def get_nested_param(keys, config):
"""
:param keys: a list of descending selector
:param config: the config source to read from (can be the config file or the defaults)
:return: the requested parameter in any format the parameter is specified
"""
param = config
for k in keys:
if not param.has_key(k):
return None
param = param[k]
return param
@staticmethod
def get_service_list():
"""
Query registrator to get the list of services
NOTE: we assume that consul is a valid URL
:return: a list of service names
"""
service_dict = requests.get('http://consul:8500/v1/catalog/services').json()
service_list = []
for s in service_dict:
service_list.append(s)
return service_list
@staticmethod
def get_service_info(service_name):
"""
Query registrator to get the details about a service
NOTE: we assume that consul is a valid URL
:param service_name: the name of the service, can be retrieved from get_service_list
:return: the informations about a service
"""
response = requests.get('http://consul:8500/v1/catalog/service/%s' % service_name)
if not response.ok:
raise Exception('[XOS-Config] Registrator is down')
service = response.json()
if not service or len(service) == 0:
raise Exception('[XOS-Config] The service missing-service looking for does not exist')
return {
'name': service[0]['ServiceName'],
'url': service[0]['ServiceAddress'],
'port': service[0]['ServicePort']
}
@staticmethod
def get_service_endpoint(service_name):
"""
Query registrator to get the details about a service and return the endpoint in for of a string
:param service_name: the name of the service, can be retrieved from get_service_list
:return: the endpoint of the service
"""
service = Config.get_service_info(service_name)
return 'http://%s:%s' % (service['url'], service['port'])
if __name__ == '__main__':
Config.init()