def _load_configuration(self):
""" Try and load configuration based on the predefined precendence """
self.config_reader = ConfigReader(self._config_path)
self.credentials_reader = CredentialsReader(
self._get_credentials_path())
self.metadata_reader = MetadataReader(self._metadata_server)
self._load_credentials()
self._load_region()
self._load_hostname()
# TODO: implement Auto Scaling Group
self._set_endpoint()
self.debug = self.config_reader.debug
self.pass_through = self.config_reader.pass_through
self._check_configuration_integrity()
def _load_configuration(self):
""" Try and load configuration based on the predefined precendence """
self.config_reader = ConfigReader(self._config_path)
self.credentials_reader = CredentialsReader(
self._get_credentials_path())
self.metadata_reader = MetadataReader(self._metadata_server)
self._load_credentials()
self._load_region()
self._load_hostname()
self._load_proxy_server_name()
self._load_proxy_server_port()
self._set_endpoint()
self._set_ec2_endpoint()
self._load_autoscaling_group()
self.debug = self.config_reader.debug
self.pass_through = self.config_reader.pass_through
self.push_asg = self.config_reader.push_asg
self.push_constant = self.config_reader.push_constant
self.constant_dimension_value = self.config_reader.constant_dimension_value
self._check_configuration_integrity()
class ConfigHelper(object):
"""
The configuration helper is responsible for obtaining configuration data from number
of sources based on predefined configuration precendence.
The configuration precedence from highest to lowest:
1. Plugin Config File
2. Environment Variables
3. Metadata
4. Collectd config file
Keyword arguments:
config_path -- The path to the plugin configuration file (Default '/opt/AmazonCloudWatchAgent/.aws/config')
metadata_server -- The address of the metadata server (Default 'http://169.254.169.254/')
"""
_LOGGER = get_logger(__name__)
_DEFAULT_AGENT_ROOT_FOLDER = os.path.join(
os.path.dirname(__file__), os.pardir, os.pardir,
'./config/') # '/opt/AmazonCloudWatchAgent/'
_DEFAULT_CONFIG_PATH = _DEFAULT_AGENT_ROOT_FOLDER + 'plugin.conf'
_DEFAULT_CREDENTIALS_PATH = _DEFAULT_AGENT_ROOT_FOLDER + ".aws/credentials"
_METADATA_SERVICE_ADDRESS = 'http://169.254.169.254/'
WHITELIST_CONFIG_PATH = _DEFAULT_AGENT_ROOT_FOLDER + 'whitelist.conf'
BLOCKED_METRIC_PATH = _DEFAULT_AGENT_ROOT_FOLDER + 'blocked_metrics'
def __init__(self,
config_path=_DEFAULT_CONFIG_PATH,
metadata_server=_METADATA_SERVICE_ADDRESS):
self._config_path = config_path
self._metadata_server = metadata_server
self._use_iam_role_credentials = False
self.region = ''
self.endpoint = ''
self.ec2_endpoint = ''
self.host = ''
self.asg_name = 'NONE'
self.proxy_server_name = ''
self.proxy_server_port = ''
self.debug = False
self.pass_through = False
self.push_asg = False
self.push_constant = False
self.constant_dimension_value = ''
self._load_configuration()
self.whitelist = Whitelist(
WhitelistConfigReader(self.WHITELIST_CONFIG_PATH,
self.pass_through).get_regex_list(),
self.BLOCKED_METRIC_PATH)
@property
def credentials(self):
"""
Returns credentials. If IAM role is used, credentials will be updated.
Otherwise old credentials are returned.
"""
if self._use_iam_role_credentials:
try:
self._credentials = self._get_credentials_from_iam_role()
except:
self._LOGGER.warning(
"Could not retrieve credentials using IAM Role. Using old credentials instead."
)
return self._credentials
@credentials.setter
def credentials(self, credentials):
self._credentials = credentials
def _load_configuration(self):
""" Try and load configuration based on the predefined precendence """
self.config_reader = ConfigReader(self._config_path)
self.credentials_reader = CredentialsReader(
self._get_credentials_path())
self.metadata_reader = MetadataReader(self._metadata_server)
self._load_credentials()
self._load_region()
self._load_hostname()
self._load_proxy_server_name()
self._load_proxy_server_port()
self._set_endpoint()
self._set_ec2_endpoint()
self._load_autoscaling_group()
self.debug = self.config_reader.debug
self.pass_through = self.config_reader.pass_through
self.push_asg = self.config_reader.push_asg
self.push_constant = self.config_reader.push_constant
self.constant_dimension_value = self.config_reader.constant_dimension_value
self._check_configuration_integrity()
def _get_credentials_path(self):
credentials_path = self.config_reader.credentials_path
if not self.config_reader.credentials_path:
credentials_path = self._DEFAULT_CREDENTIALS_PATH
return credentials_path
def _load_credentials(self):
"""
Tries to load credentials from plugin configuration file. If such file does not exist
or does not contain credentials, then IAM role is used.
"""
self.credentials = self.credentials_reader.credentials
if not self.credentials:
self._use_iam_role_credentials = True
self.credentials = self._get_credentials_from_iam_role()
def _get_credentials_from_iam_role(self):
""" Queries IAM Role metadata for latest credentials """
return self.metadata_reader.get_iam_role_credentials(
self.metadata_reader.get_iam_role_name())
def _load_region(self):
"""
Loads region from plugin configuration file, if such file does not exist or does not
contain region information, then metadata service is used.
"""
if self.config_reader.region:
self.region = self.config_reader.region
else:
try:
self.region = self.metadata_reader.get_region()
except Exception as e:
ConfigHelper._LOGGER.warning(
"Cannot retrieve region from the local metadata server. Cause: "
+ str(e))
def _load_hostname(self):
"""
Load host from the configuration file, if configuration file does not contain host entry
then try to retrieve Instance ID from local metadata service.
"""
if self.config_reader.host:
self.host = self.config_reader.host
else:
try:
self.host = self.metadata_reader.get_instance_id()
except Exception as e:
ConfigHelper._LOGGER.warning(
"Cannot retrieve Instance ID from the local metadata server. Cause: "
+ str(e) + " Using host information provided by Collectd.")
def _set_ec2_endpoint(self):
""" Creates endpoint from region information """
if self.region is "localhost":
self.ec2_endpoint = "http://" + self.region + "/"
elif self.region.startswith("cn-"):
self.ec2_endpoint = "https://ec2." + self.region + ".amazonaws.com.cn/"
else:
self.ec2_endpoint = "https://ec2." + self.region + ".amazonaws.com/"
def _load_proxy_server_name(self):
"""
Load proxy server name from the configuration file, if configuration file does not contain proxy entry
then set proxy to None.
"""
if self.config_reader.proxy_server_name:
self.proxy_server_name = self.config_reader.proxy_server_name
else:
self.proxy_server_name = None
def _load_proxy_server_port(self):
"""
Load proxy server port from the configuration file, if configuration file does not contain proxy port entry
then set proxy to None.
"""
if self.config_reader.proxy_server_port:
self.proxy_server_port = self.config_reader.proxy_server_port
else:
self.proxy_server_port = None
def _set_endpoint(self):
""" Creates endpoint from region information """
if self.region is "localhost":
self.endpoint = "http://" + self.region + "/"
elif self.region.startswith("cn-"):
self.endpoint = "https://monitoring." + self.region + ".amazonaws.com.cn/"
else:
self.endpoint = "https://monitoring." + self.region + ".amazonaws.com/"
def _load_autoscaling_group(self):
"""
Get the ASG name, if applicable. Defaults to NONE if anything goes wrong
"""
try:
instance_id = self.metadata_reader.get_instance_id()
ec2Client = EC2GetClient(self)
self.asg_name = ec2Client.get_autoscaling_group(instance_id)
ConfigHelper._LOGGER.info("Fetched asg name as " + self.asg_name)
except Exception as e:
self.asg_name = "NONE"
ConfigHelper._LOGGER.warning(
"Failed to fetch auto scaling group name. Cause: ")
ConfigHelper._LOGGER.error(traceback.format_exc())
def _check_configuration_integrity(self):
""" Check the state of this configuration helper object to ensure that all required values are loaded """
if not self._credentials:
raise ValueError("AWS _credentials are missing.")
if not self._credentials.access_key:
raise ValueError("AWS access key is missing.")
if not self._credentials.secret_key:
raise ValueError("AWS secret key is missing.")
if not self.region:
raise ValueError("Region is missing")