uncloud-mravi/uncloud/common/settings.py

136 lines
5 KiB
Python

import configparser
import logging
import sys
import os
from datetime import datetime
from uncloud.common.etcd_wrapper import Etcd3Wrapper
from os.path import join as join_path
logger = logging.getLogger(__name__)
settings = None
class CustomConfigParser(configparser.RawConfigParser):
def __getitem__(self, key):
try:
result = super().__getitem__(key)
except KeyError as err:
raise KeyError(
'Key \'{}\' not found in configuration. Make sure you configure uncloud.'.format(
key
)
) from err
else:
return result
class Settings(object):
def __init__(self, conf_dir, seed_value=None):
conf_name = 'uncloud.conf'
self.config_file = join_path(conf_dir, conf_name)
# this is used to cache config from etcd for 1 minutes. Without this we
# would make a lot of requests to etcd which slows down everything.
self.last_config_update = datetime.fromtimestamp(0)
self.config_parser = CustomConfigParser(allow_no_value=True)
self.config_parser.add_section('etcd')
self.config_parser.set('etcd', 'base_prefix', '/')
if os.access(self.config_file, os.R_OK):
self.config_parser.read(self.config_file)
else:
raise FileNotFoundError('Config file %s not found!', self.config_file)
self.config_key = join_path(self['etcd']['base_prefix'] + 'uncloud/config/')
self.read_internal_values()
if seed_value is None:
seed_value = dict()
self.config_parser.read_dict(seed_value)
def get_etcd_client(self):
args = tuple()
try:
kwargs = {
'host': self.config_parser.get('etcd', 'url'),
'port': self.config_parser.get('etcd', 'port'),
'ca_cert': self.config_parser.get('etcd', 'ca_cert'),
'cert_cert': self.config_parser.get('etcd', 'cert_cert'),
'cert_key': self.config_parser.get('etcd', 'cert_key'),
}
except configparser.Error as err:
raise configparser.Error(
'{} in config file {}'.format(
err.message, self.config_file
)
) from err
else:
try:
wrapper = Etcd3Wrapper(*args, **kwargs)
except Exception as err:
logger.error(
'etcd connection not successfull. Please check your config file.'
'\nDetails: %s\netcd connection parameters: %s',
err,
kwargs,
)
sys.exit(1)
else:
return wrapper
def read_internal_values(self):
base_prefix = self['etcd']['base_prefix']
self.config_parser.read_dict(
{
'etcd': {
'file_prefix': join_path(base_prefix, 'files/'),
'host_prefix': join_path(base_prefix, 'hosts/'),
'image_prefix': join_path(base_prefix, 'images/'),
'image_store_prefix': join_path(base_prefix, 'imagestore/'),
'network_prefix': join_path(base_prefix, 'networks/'),
'request_prefix': join_path(base_prefix, 'requests/'),
'user_prefix': join_path(base_prefix, 'users/'),
'vm_prefix': join_path(base_prefix, 'vms/'),
'vxlan_counter': join_path(base_prefix, 'counters/vxlan'),
'tap_counter': join_path(base_prefix, 'counters/tap')
}
}
)
def read_config_file_values(self, config_file):
try:
# Trying to read configuration file
with open(config_file) as config_file_handle:
self.config_parser.read_file(config_file_handle)
except FileNotFoundError:
sys.exit('Configuration file {} not found!'.format(config_file))
except Exception as err:
logger.exception(err)
sys.exit('Error occurred while reading configuration file')
def read_values_from_etcd(self):
etcd_client = self.get_etcd_client()
if (datetime.utcnow() - self.last_config_update).total_seconds() > 60:
config_from_etcd = etcd_client.get(self.config_key, value_in_json=True)
if config_from_etcd:
self.config_parser.read_dict(config_from_etcd.value)
self.last_config_update = datetime.utcnow()
else:
raise KeyError('Key \'{}\' not found in etcd. Please configure uncloud.'.format(self.config_key))
def __getitem__(self, key):
# Allow failing to read from etcd if we have
# it locally
if key not in self.config_parser.sections():
try:
self.read_values_from_etcd()
except KeyError:
pass
return self.config_parser[key]
def get_settings():
return settings