blob: aac6ffba4e3c474f201f430f081fce4aca084017 [file] [log] [blame]
# 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 default
from pykwalify.core import Core as PyKwalify
import pykwalify
pykwalify.init_logging(1)
DEFAULT_CONFIG_FILE = "/opt/xos/xos_config.yaml"
DEFAULT_CONFIG_SCHEMA = "xos-config-schema.yaml"
INITIALIZED = False
CONFIG_FILE = None
CONFIG = {}
OVERRIDE_CONFIG = {}
class Config:
"""
XOS Configuration APIs
"""
@staticmethod
def init(
config_file=DEFAULT_CONFIG_FILE,
config_schema=DEFAULT_CONFIG_SCHEMA,
override_config_file=None,
):
# 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 OVERRIDE_CONFIG
global OVERRIDE_CONFIG_FILE
global OVERRIDE_CONFIG_SCHEMA
# Use same schema for both provided and global config by default
OVERRIDE_CONFIG_SCHEMA = config_schema
OVERRIDE_CONFIG_FILE = override_config_file
# 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 OVERRIDE_CONFIG_* to be overridden by env vars
if os.environ.get("XOS_OVERRIDE_CONFIG_FILE"):
OVERRIDE_CONFIG_FILE = os.environ["XOS_OVERRIDE_CONFIG_FILE"]
if os.environ.get("XOS_OVERRIDE_CONFIG_SCHEMA"):
OVERRIDE_CONFIG_SCHEMA = Config.get_abs_path(
os.environ["XOS_OVERRIDE_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)
# if an override is set
if OVERRIDE_CONFIG_FILE is not None:
OVERRIDE_CONFIG = Config.read_config(
OVERRIDE_CONFIG_FILE, OVERRIDE_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 as e:
try:
error_msg = e.msg
except AttributeError:
error_msg = str(e)
raise Exception("[XOS-Config] The config format is wrong: %s" % error_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 OVERRIDE_CONFIG
global OVERRIDE_CONFIG_FILE
if not INITIALIZED:
raise Exception("[XOS-Config] Module has not been initialized")
val = Config.get_param(query, CONFIG)
if OVERRIDE_CONFIG_FILE or not val:
# if we specified an override configuration, we should override the value
# we also look for the value in case it's missing
over_val = Config.get_param(query, OVERRIDE_CONFIG)
if over_val is not None:
val = over_val
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 key not in config:
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 k not in param:
return None
param = param[k]
return param
if __name__ == "__main__":
Config.init()