aws-ec2: NatProvider.instanceV2 primary network interface #29720
Description
Describe the bug
Provided user data by NatInstanceProviderV2 uses incorrect primary network interface eth0 instead of ens5 (or similar).
userData.addCommands(
'yum install iptables-services -y',
'systemctl enable iptables',
'systemctl start iptables',
'echo "net.ipv4.ip_forward=1" > /etc/sysctl.d/custom-ip-forwarding.conf',
'sudo sysctl -p /etc/sysctl.d/custom-ip-forwarding.conf',
'sudo /sbin/iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE',
'sudo /sbin/iptables -F FORWARD',
'sudo service iptables save',
);
Expected Behavior
Nat instance forwards traffic
Current Behavior
Traffic not forwarded
Reproduction Steps
Simply use the example snippet from cdk docs:
const provider = ec2.NatProvider.instanceV2({
instanceType,
defaultAllowedTraffic: ec2.NatTrafficDirection.OUTBOUND_ONLY,
});
new ec2.Vpc(this, 'TheVPC', {
natGatewayProvider: provider,
});
Possible Solution
Instead of hardcoding the network interface, use the actual from the os.
Additional Information/Context
No response
CDK CLI Version
2.133.0
Framework Version
No response
Node.js Version
OS
Language
TypeScript
Language Version
No response
Other information
No response