Add VPC DHCP Options

[jen20]

It is common to configure a DHCP Options Set when creating a VPC, which allows DNS Servers, a custom search domain, NTP servers and a few other parameters to instances via the DHCP system built into the VPC control plane.

Currently the following function can be used to add an options set for a custom search domain.

function addDhcpOptions(namePrefix: string, baseTags: aws.Tags, zoneName: string, vpc: awsx.ec2.Vpc): pulumi.Output<string> {
    const privateZone = new aws.route53.Zone(`${namePrefix}-private-hosted-zone`, {
        vpcs: [{
            vpcId: vpc.id,
        }],
        name: zoneName,
        comment: `Private zone for ${zoneName}. Managed by Pulumi.`,
    }, {parent: vpc});

    const dhcpOptionSet = new aws.ec2.VpcDhcpOptions(`${namePrefix}-dhcp-options`, {
        domainName: privateZone.name,
        domainNameServers: ["AmazonProvidedDNS"],
        tags: Object.assign({
            Name: `DHCP Options (${zoneName})`,
        }, baseTags),
    }, vpc);

    new aws.ec2.VpcDhcpOptionsAssociation(`${namePrefix}-dhcp-options-assoc`, {
        vpcId: vpc.id,
        dhcpOptionsId: dhcpOptionSet.id,
    }, {parent: dhcpOptionSet});

    return privateZone.zoneId;
}

Note: the above program also creates the zone itself, which I do not believe should be done by the Vpc class.

It would be nice to allow a zone ID or name to be passed to the VpcArgs of awsx.ec2.Vpc in order that this can be done automatically, and that the zone ID can be exposed as one of the outputs of the Vpc instead of being passed around separately to create records on it.