def change_dir(self, argument_list):
"""
Change the current working directory to another directory
Input:
- argument_list: Arguments interepred from user input
Output:
- A print message indicate whether the function runs smoothly or
has any error.
"""
# Change the current working directory to the directory whose path is
# the 1st argument after "cd". If there is none of them, change it to
# the directory that is recorded as HOME variable in the environ
try:
new_dir = (argument_list[1] if len(argument_list) > 1
else self.environ_dict["HOME"])
chdir(new_dir if not new_dir.startswith("~")
else expanduser(new_dir))
self.environ_dict["PWD"] = getcwd()
return ""
except PermissionError:
return get_error_message(new_dir, PermissionError, "cd")
except FileNotFoundError:
return get_error_message(new_dir, FileNotFoundError, "cd")
except NotADirectoryError:
return get_error_message(new_dir, NotADirectoryError, "cd")
# When the HOME environ variable is not set, this error will raise
except KeyError:
return "intek-sh: cd: HOME not set"
def lambda_rename_dbinstance(event, context):
"""Handles rename of a DB instance"""
region = os.environ['Region']
rds = boto3.client('rds', region)
result = {}
original_instance_identifier = ''
modified_instance_identifier = ''
try:
if event.get('Error') == 'InstanceRestoreException' and \
'Identifier' in event.get('Cause'):
#rename revert scenario in case of db restore failure
response = util.get_identifier_from_error(event)
modified_instance_identifier = response["modified_identifier"]
original_instance_identifier = response["original_identifier"]
else:
original_instance_identifier = event['identifier']
modified_instance_identifier = event['identifier'] + '-temp'
rds.modify_db_instance(
DBInstanceIdentifier = original_instance_identifier,
ApplyImmediately = True,
NewDBInstanceIdentifier = modified_instance_identifier)
result['taskname'] = constants.RENAME
result['identifier'] = modified_instance_identifier
return result
except Exception as error:
error_message = util.get_error_message(original_instance_identifier, error)
if constants.RATE_EXCEEDED in str(error):
raise custom_exceptions.RateExceededException(error_message)
else:
raise custom_exceptions.RenameException(error_message)
def lambda_delete_dbcluster(event, context):
"""Handles deletion of a DB cluster and its corresponding readers and writers"""
region = os.environ['Region']
rds = boto3.client('rds', region)
result = {}
cluster_id = event['identifier'] + constants.TEMP_POSTFIX
try:
describe_db_response = rds.describe_db_clusters(
DBClusterIdentifier=cluster_id)
for db_cluster_member in describe_db_response['DBClusters'][0][
'DBClusterMembers']:
rds.delete_db_instance(
DBInstanceIdentifier=db_cluster_member['DBInstanceIdentifier'],
SkipFinalSnapshot=True)
rds.delete_db_cluster(DBClusterIdentifier=cluster_id,
SkipFinalSnapshot=True)
result['taskname'] = constants.DELETE
result['identifier'] = cluster_id
return result
except Exception as error:
error_message = util.get_error_message(cluster_id, error)
if constants.RATE_EXCEEDED in str(error):
raise custom_exceptions.RateExceededException(error_message)
else:
raise custom_exceptions.DeletionException(error_message)
def lambda_restore_dbinstance(event, context):
"""Handles restore of a db instance from its snapshot"""
region = os.environ['Region']
rds = boto3.client('rds', region)
result = {}
response = util.get_modified_identifier(event['identifier'])
try:
describe_db_response = rds.describe_db_instances(
DBInstanceIdentifier=event['identifier'])
vpc_security_groups = describe_db_response['DBInstances'][0][
'VpcSecurityGroups']
vpc_security_group_ids = []
for vpc_security_group in vpc_security_groups:
vpc_security_group_ids.append(
vpc_security_group['VpcSecurityGroupId'])
rds.restore_db_instance_from_db_snapshot(
DBInstanceIdentifier=response["instance_id"],
DBSnapshotIdentifier=response["snapshot_id"],
DBSubnetGroupName=describe_db_response['DBInstances'][0]
['DBSubnetGroup']['DBSubnetGroupName'],
VpcSecurityGroupIds=vpc_security_group_ids)
result['taskname'] = constants.DB_RESTORE
result['identifier'] = response["instance_id"]
return result
except Exception as error:
error_message = util.get_error_message(response["instance_id"], error)
if constants.RATE_EXCEEDED in str(error):
raise custom_exceptions.RateExceededException(error_message)
else:
raise custom_exceptions.InstanceRestoreException(error_message)
def lambda_restore_dbcluster(event, context):
"""Handles restore of a db cluster from its snapshot"""
region = os.environ['Region']
result = {}
rds = boto3.client('rds', region)
old_cluster_id = event['identifier']
response = util.get_modified_identifier(event['identifier'])
cluster_id = response["instance_id"]
cluster_snapshot_id = response["snapshot_id"]
try:
describe_db_response = rds.describe_db_clusters(
DBClusterIdentifier=old_cluster_id)
vpc_security_groups = describe_db_response['DBClusters'][0][
'VpcSecurityGroups']
engine = describe_db_response['DBClusters'][0]['Engine']
engine_version = describe_db_response['DBClusters'][0]['EngineVersion']
vpc_security_groups_ids = []
for vpc_security_group in vpc_security_groups:
vpc_security_groups_ids.append(
vpc_security_group['VpcSecurityGroupId'])
rds.restore_db_cluster_from_snapshot(
DBClusterIdentifier=cluster_id,
SnapshotIdentifier=cluster_snapshot_id,
Engine=engine,
EngineVersion=engine_version,
DBSubnetGroupName=describe_db_response['DBClusters'][0]
['DBSubnetGroup'],
Port=describe_db_response['DBClusters'][0]['Port'],
DatabaseName=describe_db_response['DBClusters'][0]['DatabaseName'],
VpcSecurityGroupIds=vpc_security_groups_ids)
for db_cluster_member in describe_db_response['DBClusters'][0][
'DBClusterMembers']:
desc_db_response = rds.describe_db_instances(
DBInstanceIdentifier=db_cluster_member['DBInstanceIdentifier'])
dbinstance_identifier = util.get_modified_identifier(
db_cluster_member['DBInstanceIdentifier'])["instance_id"]
rds.create_db_instance(
DBInstanceIdentifier=dbinstance_identifier,
DBInstanceClass=desc_db_response['DBInstances'][0]
['DBInstanceClass'],
Engine=engine,
DBClusterIdentifier=cluster_id)
result['taskname'] = constants.CLUSTER_RESTORE
result['identifier'] = cluster_id
return result
except Exception as error:
error_message = util.get_error_message(cluster_id, error)
if constants.RATE_EXCEEDED in str(error):
raise custom_exceptions.RateExceededException(error_message)
else:
raise custom_exceptions.ClusterRestoreException(error_message)
def lambda_delete_dbinstance(event, context):
"""Handles deletion of a RDS db instance"""
region = os.environ['Region']
rds = boto3.client('rds', region)
result = {}
instance_id = event['identifier'] + constants.TEMP_POSTFIX
try:
rds.delete_db_instance(DBInstanceIdentifier=instance_id,
SkipFinalSnapshot=True)
result['taskname'] = constants.DELETE
result['identifier'] = instance_id
return result
except Exception as error:
error_message = util.get_error_message(instance_id, error)
if constants.RATE_EXCEEDED in str(error):
raise custom_exceptions.RateExceededException(error_message)
else:
raise custom_exceptions.DeletionException(error_message)
def cluster_instance_rename_reversal(event, rds):
"""in case of failure at the Restore step, revert the initial rename of cluster readers and writers to unblock any activity on the db"""
response = {}
response = util.get_identifier_from_error(event)
try:
describe_response = rds.describe_db_clusters(
DBClusterIdentifier = response["original_identifier"]
)
# revert the rename of the reader and writer instances before renaming the cluster
for db_cluster_member in describe_response['DBClusters'][0]['DBClusterMembers']:
old_dbinstance_id = db_cluster_member['DBInstanceIdentifier']
new_dbinstance_id = util.get_modified_identifier(old_dbinstance_id)["instance_id"]
rds.modify_db_instance(
DBInstanceIdentifier = old_dbinstance_id,
ApplyImmediately = True,
NewDBInstanceIdentifier = new_dbinstance_id
)
response["original_cluster_identifier"] = response["original_identifier"]
response["modified_cluster_identifier"] = response["modified_identifier"]
return response
except Exception as error:
error_message = util.get_error_message(response["modified_identifier"], error)
raise Exception(error_message)
def cluster_instance_rename(event,rds):
"""rename of the reader and writer instances in a cluster"""
response = {}
original_cluster_identifier = event['identifier']
modified_cluster_identifier = event['identifier'] + constants.TEMP_POSTFIX
try:
describe_response = rds.describe_db_clusters(
DBClusterIdentifier = original_cluster_identifier
)
#rename the reader and writer instances before renaming the cluster
for db_cluster_member in describe_response['DBClusters'][0]['DBClusterMembers']:
old_dbinstance_id = db_cluster_member['DBInstanceIdentifier']
new_dbinstance_id = old_dbinstance_id + constants.TEMP_POSTFIX
rds.modify_db_instance(
DBInstanceIdentifier = old_dbinstance_id,
ApplyImmediately = True,
NewDBInstanceIdentifier = new_dbinstance_id
)
response["original_cluster_identifier"] = original_cluster_identifier
response["modified_cluster_identifier"] = modified_cluster_identifier
return response
except Exception as error:
error_message = util.get_error_message(modified_cluster_identifier, error)
raise Exception(error_message)