Hey everyone is there a way to get the private and public su

Question

Hey everyone is there a way to get the private and public subnets from an existing VPC using the look up method in Python

green-stone-37839 · Answer

Hi Luis the one way to tell the difference is to determine if a subnet has a route table route targeting an internet gateway Having this route would mean its public This isn t a great way to answer your question programmatically IMO the best way to identify public private subnets is to use an arbitrary tag of your choice eg Type == Public Private then use that tag in a `get subnet ids ` lookup

hallowed-teacher-48474 · Answer

Thanks < green stone 37839> I implemented something similar with Boto3 using the presence of the IGW or NAT in the routes table but was wondering if there was already something implemented in Pulumi Guess will port it to Pulumi using ec2 functions slightly smiling face

hallowed-teacher-48474 · Answer

Created this little python helper in case anyone has the need to get public private and isolated subnets from an existing VPC slightly smiling face Code can be optimized sweat smile ```import pulumi import pulumi aws as aws INTERNET ROUTE TYPE NAT = nat gateway INTERNET ROUTE TYPE IGW = internet gateway INTERNET ROUTE TYPE ISO = isolated class PulumiNetworkHelper def init self gt None pass def lookup internet route type self routeTableId route = aws ec2 get route route table id = routeTableId destination cidr block = 0 0 0 0 0 if route == None or not route gateway id and not route instance id and not route nat gateway id return INTERNET ROUTE TYPE ISO if route gateway id return INTERNET ROUTE TYPE IGW if route instance id or route nat gateway id return INTERNET ROUTE TYPE NAT return None def get subnets by internet route type self vpcId internetRouteType subnets = routeTables = aws ec2 get route tables vpc id = vpcId for routeTableId in routeTables ids routeTable = aws ec2 get route table route table id = routeTableId routeTableSubnets = association subnet id for association in routeTable associations if association subnet id if self lookup internet route type routeTableId == internetRouteType subnets = subnets + routeTableSubnets return subnets def get isolated subnets self vpcId return self get subnets by internet route type vpcId INTERNET ROUTE TYPE ISO def get private subnets self vpcId return self get subnets by internet route type vpcId INTERNET ROUTE TYPE NAT def get public subnets self vpcId return self get subnets by internet route type vpcId INTERNET ROUTE TYPE IGW ``` And in your pulumi stack just use it like this ```helper = PulumiNetworkHelper print Private Subnets print helper get private subnets from vpc vpc abcd123 ```