let myAppServiceRegistryService = new aws.servicediscovery.Service("myApp", {
    dnsConfig: {
        namespaceId: nodeServiceDiscoveryNamespace.id,
        dnsRecords: [{
            ttl: 10,
            type: "A"
        }],
        routingPolicy: "MULTIVALUE"
    }
});

let myAppFargateService = new awsx.ecs.FargateService("myApp", {
    ...
    serviceRegistries: {
        registryArn: myServiceRegistry.arn,
        containerName: myAppServiceRegistryService
    }
});

new awsx.ecs.FargateService("myOtherService", {
    ...
    taskDefinitionArgs: {
        containers: {
            [`${serviceName}`]: {
                environment: [{
                    name: "APP_HOSTNAME",
                    value: aws.servicediscovery.Service.get(myAppFargateService.name, myAppFargateService.id)
                }]
            }
        }
    }
});