def clean_route_tables(peering_id: str, vpc_id: str, account_id: str, region: str, dryrun: bool) -> None:
"""
Deletes any routes pointing at a given peering id for a given vpc.
Only applies to route tables with tag peerd_eligible:true
:param peering_id: A vpc peering id e.g. pcx-011a291e5affc8d95
:type peering_id: str
:param vpc_id: A vpc id e.g. vpc-abc123
:type vpc_id: str
:param account_id: An AWS account id number
:type account: str
:param region: An AWS region where the service client should be created. e.g. us-east-1
:type region: str
"""
# Initialise EC2 client
ec2_client = aws_client(account_id, 'ec2', region)
# Get the route tables for the VPC
if not (route_tables := vpc_route_tables(vpc_id, account_id, region)):
LOGGER.warning(f'No peerd_eligible route tables in VPC {vpc_id}')
return
def update_route_tables(target_peerings: list, metadata: Mapping,
dryrun: bool) -> None:
"""
Loops through a list of peerings and updates the route tables on each side.
Example target_peerings:
```
[
[
{
"account_id": 415432961280,
"vpc_id": "vpc-e08fb484",
"region": "ap-southeast-2",
"cidr_overrides": [
"10.53.101.0/27"
],
"peering_tags": [
{
"peerd_az_affinity": "0"
}
]
},
{
"account_id": 415432961280,
"vpc_id": "vpc-7a83b81e",
"region": "ap-southeast-2"
}
]
]
```
:param target_peerings: A list of lists representing the requester and accepter for each peering.
:type target_peerings: list
:param metadata: A dictionary with the environment, owner, etc for tagging
:type metadata: list
"""
# We need to handle both sides of the peerings so we append reverse of each peering.
# This means every side of every peering will be seen by a single loop.
# We do this to avoid extra code handling the AWS concept of "accepter" and "requester"
# We also construct our route table cache by account and region, which means if we looped
# by requester and accepter we could cache stale route table contents.
target_peerings.extend([x[::-1] for x in target_peerings])
# Loop through the target peerings
for peering_descriptor in target_peerings:
# Unpack some common variables
account_id = peering_descriptor[0]['account_id']
vpc_id = peering_descriptor[0]['vpc_id']
region = peering_descriptor[0]['region']
remote_account_id = peering_descriptor[1]['account_id']
remote_vpc_id = peering_descriptor[1]['vpc_id']
remote_region = peering_descriptor[1]['region']
# Get the remote CIDRs from the AWS VPC API, or use the overrides in the config if they exist.
remote_cidrs = peering_descriptor[1].get(
'cidr_overrides',
list_vpc_cidrs(remote_vpc_id, remote_account_id, remote_region))
LOGGER.info(
f"Inspecting route tables in {account_id} {vpc_id} "
f"{region}, peer: {remote_account_id} {remote_vpc_id} {remote_region}"
)
# Initialise a ec2 client connection
ec2_client = aws_client(account_id, 'ec2', region)
# Get active VPC peering if one exists, else continue
# We want to avoid adding routes for inactive peerings.
filters = [{
'Name': 'tag:peerd_created',
'Values': ['true']
}, {
'Name': 'tag:peerd_environment',
'Values': [metadata['environment']]
}, {
'Name': 'status-code',
'Values': ['active', 'provisioning']
}]
if not (peering := get_vpc_peering(vpc_id, remote_vpc_id, account_id,
region, filters)):
# Since we filter for the peerd environment, remind the user that there could be a peering
# But that it might exist as part of another environment, and thus we won't be touching it.
LOGGER.warning(
f'No active peering between {vpc_id} and {remote_vpc_id} for this environment'
f' {metadata["environment"]}. It may exist as part of another environment.'
)
continue
peering_id = peering['VpcPeeringConnectionId']
# Wait until the peering is active, not provisioning (boto waiter doesn't accept filters for vpc peering api)
# We must wait for active state to install routes, otherwise the peering will be ignored.
# Note, usually this step takes a few seconds, but can sometimes take up to a minute or two in rare cases.
if peering['Status']['Code'] == 'provisioning':
while not ec2_client.describe_vpc_peering_connections(
Filters=[{
'Name': 'status-code',
'Values': ['active']
}, {
'Name': 'vpc-peering-connection-id',
'Values': [peering_id]
}])['VpcPeeringConnections']:
LOGGER.info(
f'Waiting for peering {peering_id} to become active...')
sleep(5)
# Get the route tables for the local vpc relevant to the peering.
# The vpc_route_tables function will only return peerd_eligible:true tables
# Since we will have cases where RTs should not be altered.
if not (route_tables := vpc_route_tables(vpc_id, account_id, region)):
LOGGER.warning(f'No peerd_eligible route tables in VPC {vpc_id}')
continue