Aws-cdk: Access a Vpc's Internet Gateway

[jeanblanchard]

Add an accessor to the Internet Gateway that was created by the Vpc construct.

Use Case

Trying to add a PublicSubnet to an existing Vpc (with existing public subnets), there is no way to create a route to the Vpc's existing Internet Gateway, because the reference is not exposed anywhere (that I could find), so the PublicSubnet is not effectively public.

Proposed Solution

• Either add an accessor to a VPC's internet gateway, if any
• Or have the PublicSubnet constructor automagically create the route from the VPC it's a part of.

(Or, ideally, both)

Other

I'd take a workaround within CDK, that allows this without creating (and paying for) a second IGW...

• [ ] :wave: I may be able to implement this feature request
• [ ] :warning: This feature might incur a breaking change

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This is a :rocket: Feature Request

[jeanblanchard]

Update - I found my workaround, using an escape hatch to get the "IGW" child resource in the Vpc construct:

    const igw = vpc.node.findChild('IGW') as CfnInternetGateway;
    new CfnRoute(this, 'IGW', {
      routeTableId: subnet.routeTable.routeTableId,
      destinationCidrBlock: '0.0.0.0/0',
      gatewayId: igw.ref,
    });

[SomayaB]

Glad you could figure it out! :) Closing this issue. Feel free to reopen.

[shearn89]

Having a stab at this, hope to have a PR out soon.