def execute_query(conn, query_expr: dict) -> str:
"""A helper function to execute a query against Dynamo db.
Args:
conn (func): A connection to the Dynamodb table (from db_connector).
query_expr (dict): A dictionary containing Dynamodb-specific query
attributes: KeyConditionExpression and IndexName (if applicable).
Raises:
RegistryClientError if connecting to or querying the database fails.
Returns:
The Dynamodb query API results as JSON."""
try:
if 'IndexName' not in query_expr.keys():
response = conn.query(
KeyConditionExpression=query_expr['KeyConditionExpression'])
else:
response = conn.query(
IndexName=query_expr['IndexName'],
KeyConditionExpression=query_expr['KeyConditionExpression'])
except ClientError as e:
logger.error("crud: Unexpected error: %s" % e)
raise RegistryClientError(f"Unexpected error querying the "
f"registry: {str(e)}")
logger.debug(f"Dynamodb response={response}")
return response
def delete_bond(conn, bond_id: str) -> None:
"""Delete a bond. Does nothing if the bond does not exist.
Args:
conn (func): A connection to the Dynamodb table (from db_connector).
bond_id (str): The bond id of the bond to delete.
Raises:
RegistryClientError if connecting to or querying the database fails."""
logger.debug(f"crud: delete bond: bond_id={bond_id}")
try:
response = conn.delete_item(Key={'bond_id': bond_id})
except ClientError as e:
logger.error("crud: Unexpected error: %s" % e)
raise RegistryClientError(f"Unexpected error querying the "
f"registry: {str(e)}")
logger.debug(f"Dynamodb response={response}")
def remove_subscriber(bond_id: str, sid: str) -> Bond:
"""Remove a subscriber from a bond. Ignore if the subscriber is not
a current subscriber attached to the bond.
Args:
bond_id (str): The bond id of the bond to remove the subscriber from.
sid (str): The subscriber identifier of the subscriber to be removed.
Raises:
RegistryClientError if connecting to or querying the database fails.
ConditionalCheckError if the bond does not exist.
Returns:
The updated bond object."""
logger.debug(f"crud: remove subscriber: bond_id={bond_id}, sid={sid}")
bond = get_bond(bond_id)
if bond is None:
raise ConditionalCheckError(f'Bond {bond_id} not found. '
f'Cannot remove subscriber {sid}.')
bond.remove_subscriber(sid)
return update_bond(bond)
def add_subscriber(bond_id: str, sub: Subscriber) -> Bond:
"""Add a subscriber to a bond. Overwrite if the subscriber is already
present.
Args:
bond_id (str): The bond id of the bond to add the subscriber to.
sub (Subscriber): The subscriber object to add to the bond.
Raises:
RegistryClientError if connecting to or querying the database fails.
ConditionalCheckError if the bond does not exist.
Returns:
The updated bond object."""
logger.debug(f"crud: add subscriber: bond_id={bond_id}, sub={sub}")
bond = get_bond(bond_id)
if bond is None:
raise ConditionalCheckError(f'Bond {bond_id} not found. '
f'Cannot add subscriber {sub.sid}.')
bond.add_subscriber(sub)
return update_bond(bond)
def get_bond(bond_id: str) -> Bond:
"""Get a bond with the given id.
Args:
bond_id (str): The bond id of the bond to fetch.
Raises:
RegistryClientError if connecting to or querying the database fails.
Returns:
The requested bond object or None if not found."""
logger.debug(f"crud: get bond: bond_id={bond_id}")
query_expr = {'KeyConditionExpression': Key('bond_id').eq(bond_id)}
response = execute_query(query_expr)
if len(response["Items"]) == 0:
logger.debug(f"crud: bond not found: bond_id={bond_id}")
return None
return bond_from_item(response["Items"][0])
def with_connection_(*args, **kwargs):
"""
Open a connection to DynamoDB.
If IS_OFFLINE is set, then connect to the local instance of DynamoDB
running in Docker; Otherwise, connect to the cloud service.
(Note: moto mock DynamoDB uses this path, i.e. IS_OFFLINE is false.)
"""
is_offline = os.environ.get("IS_OFFLINE")
try:
if is_offline:
logger.debug(f'DynamoDB: OFFLINE mode. Connecting to local db')
dynamodb = \
boto3.resource(
"dynamodb",
endpoint_url='http://dynamodb-local:8000/',
region_name='us-west-2',
aws_access_key_id='AWS_ACCESS_KEY_ID',
aws_secret_access_key='AWS_SECRET_ACCESS_KEY')
else:
logger.debug(f'DynamoDB: ONLINE mode. Connecting to cloud db.')
dynamodb = boto3.resource("dynamodb")
table = dynamodb.Table("bond")
logger.debug(f'DynamoDB: Connected to {table.table_arn}')
rv = func(table, *args, **kwargs)
except ClientError as err:
logger.exception("DynamoDB: Failed to connect to the bond "
"table: %s" % err)
raise RegistryClientError(f"Failed to connect to the database: "
f"{str(err)}")
return rv
def get_bonds_by_sub_account_id(sub_account_id: str) -> List[Bond]:
"""Get all bonds for the given *subscriber* account.
Args:
sub_account_id (str): The subscriber account identifier to search on.
Raises:
RegistryClientError if connecting to or querying the database fails.
Returns:
A list of bond objects or an empty list if none are found."""
logger.debug(f"crud: get bonds by sub account id: "
f"sub_account_id={sub_account_id}")
bonds = []
query_expr = {
'IndexName': "bond-sub_account_id-index",
'KeyConditionExpression': Key('sub_account_id').eq(sub_account_id)
}
response = execute_query(query_expr)
for item in response['Items']:
bonds.append(bond_from_item(item))
return bonds
def get_bonds_by_host_cost_center(host_cost_center: str) -> List[Bond]:
"""Get all bonds for the given *host* cost center.
Args:
host_cost_center (str): The host cost center identifier to search on.
Raises:
RegistryClientError if connecting to or querying the database fails.
Returns:
A list of bond objects or an empty list if none are found."""
logger.debug(f"crud: get bonds by host cost center: "
f"host_cost_center={host_cost_center}")
bonds = []
query_expr = {
'IndexName': "bond-host_cost_center-index",
'KeyConditionExpression': Key('host_cost_center').eq(host_cost_center)
}
response = execute_query(query_expr)
for item in response['Items']:
bonds.append(bond_from_item(item))
return bonds
def update_bond(conn, bond: Bond) -> Bond:
"""Update a bond.
Args:
conn (func): A connection to the Dynamodb table (from db_connector).
bond (Bond): The bond object to update.
Raises:
RegistryClientError if connecting to or querying the database fails.
ConditionalCheckError if the bond does not exist.
Returns:
The bond object updated."""
logger.debug(f"crud: update bond: bond={bond}")
try:
response = conn.update_item(
Key={'bond_id': bond.bond_id},
UpdateExpression="set host_account_id = :had, " +
"sub_account_id = :sad, " + "host_cost_center = :hcc, " +
"sub_cost_center = :scc, " + "subscribers = :sub",
ExpressionAttributeValues={
':had': bond.host_account_id,
':sad': bond.sub_account_id,
':hcc': bond.host_cost_center,
':scc': bond.sub_cost_center,
':sub': jsonable_encoder(bond.subscribers)
},
ConditionExpression='attribute_exists(bond_id)',
ReturnValues="UPDATED_NEW")
except ClientError as e:
if e.response['Error']['Code'] == 'ConditionalCheckFailedException':
logger.debug(f"crud: bond not found: bond_id={bond.bond_id}")
raise ConditionalCheckError(f"Bond not found: "
f"bond_id={bond.bond_id}")
else:
logger.error("crud: Unexpected error: %s" % e)
raise RegistryClientError(f"Unexpected error querying the "
f"registry: {str(e)}")
logger.debug(f"Dynamodb response={response}")
return bond
def create_bond(conn, bond: Bond) -> Bond:
"""Insert a new bond.
Args:
conn (func): A connection to the Dynamodb table (from db_connector).
bond (Bond): The bond object to insert.
Raises:
RegistryClientError if connecting to or querying the database fails.
ConditionalCheckError if the bond already exists.
Returns:
The bond object inserted."""
logger.debug(f"crud: create bond: bond={bond}")
try:
response = conn.put_item(
Item={
'bond_id': bond.bond_id,
'host_account_id': bond.host_account_id,
'sub_account_id': bond.sub_account_id,
'host_cost_center': bond.host_cost_center,
'sub_cost_center': bond.sub_cost_center,
'subscribers': jsonable_encoder(bond.subscribers)
},
ConditionExpression='attribute_not_exists(bond_id)')
except ClientError as e:
if e.response['Error']['Code'] == 'ConditionalCheckFailedException':
logger.debug(f"crud: bond already exists: bond_id={bond.bond_id}")
raise ConditionalCheckError(f"Bond already exists: "
f"bond_id={bond.bond_id}")
else:
logger.error("crud: Unexpected error: %s" % e)
raise RegistryClientError(f"Unexpected error querying the "
f"registry: {str(e)}")
logger.debug(f"Dynamodb response={response}")
return bond