def validate_params(self):
"""
Validate database parameters.
Should validate that a dbtype is a valid one and that the appropriate
params have been passed for a particular db_type.
:raises ETLHelperParamsError: Error if params are invalid
"""
# Get a set of the attributes to compare against required attributes.
given = set(self.keys())
try:
required_params = DB_HELPER_FACTORY.from_dbtype(
self.dbtype).required_params
except ETLHelperHelperError:
msg = f'{self.dbtype} not in valid types ({DB_HELPER_FACTORY.helpers.keys()})'
# from None suppresses lower errors in the stack trace
# Deeper error is recorded in ETLHelperDbParamsError.__context__
raise ETLHelperDbParamsError(msg) from None
unset_params = (given ^ required_params) & required_params
if unset_params:
msg = f'{unset_params} not set. Required parameters are {required_params}'
raise ETLHelperDbParamsError(msg)
valid_params = required_params.union({'dbtype'})
bad_params = given ^ valid_params
if bad_params:
msg = f"Invalid parameter(s): {bad_params}"
raise ETLHelperDbParamsError(msg)
def from_environment(cls, prefix='ETLHelper_'):
"""
Create DbParams object from parameters specified by environment
variables e.g. ETLHelper_dbtype, ETLHelper_host, ETLHelper_port, etc.
:param prefix: str, prefix to environment variable names
"""
dbparams_keys = [key for key in os.environ if key.startswith(prefix)]
dbparams_from_env = {
key.replace(prefix, '').lower(): os.environ[key]
for key in dbparams_keys
}
# Ensure dbtype has been set
dbtype_var = f'{prefix}dbtype'
dbtype = dbparams_from_env.get('dbtype', None)
if dbtype is None:
msg = f"{dbtype_var} environment variable is not set"
raise ETLHelperDbParamsError(msg)
# Only include the required params
# This prevents something like ETLHelper_password being added
required_params = DB_HELPER_FACTORY.from_dbtype(
dbtype).required_params | {'dbtype'}
dbparams_from_env = {
key: dbparams_from_env[key]
for key in required_params
}
return cls(**dbparams_from_env)
def validate_params(self):
"""
Validate database parameters.
Should validate that a dbtype is a valid one and that the appropriate
params have been passed for a particular db_type.
:raises ETLHelperParamsError: Error if params are invalid
"""
# Get a set of the attributes to compare against required attributes.
given = set(self.keys())
try:
required_params = DB_HELPER_FACTORY.from_dbtype(self.dbtype).required_params
except ETLHelperHelperError:
msg = f'{self.dbtype} not in valid types ({DB_HELPER_FACTORY.helpers.keys()})'
raise ETLHelperDbParamsError(msg)
unset_params = (given ^ required_params) & required_params
if unset_params:
msg = f'{unset_params} not set. Required parameters are {required_params}'
raise ETLHelperDbParamsError(msg)
def from_environment(cls, prefix='ETLHelper_'):
"""
Create DbParams object from parameters specified by environment
variables e.g. ETLHelper_dbtype, ETLHelper_host, ETLHelper_port, etc.
:param prefix: str, prefix to environment variable names
"""
dbparams_keys = [key for key in os.environ if key.startswith(prefix)]
dbparams_from_env = {key.replace(prefix, '').lower(): os.environ[key]
for key in dbparams_keys}
# Ensure dbtype has been set
dbtype_var = f'{prefix}dbtype'
if 'dbtype' not in dbparams_from_env:
msg = f"{dbtype_var} environment variable is not set"
raise ETLHelperDbParamsError(msg)
return cls(**dbparams_from_env)