Hello. I use pulumi_gcp and examples below are going to be GCP related. I want to add a dns record with a value of some instance's IP address. If target instance has already been created, the reference below works perfectly (I use a list of instance objects):

#         rrdatas=[
#           dbs_instance_pulumi_objects[item].
#           network_interfaces[0]['networkIp'],
#         ],

But when you initiate the stack for the first time in a new project and all instances are yet to be created alongside DNS records, 

networkInterfaces

 only contains this

networkInterfaces     : [
            [0]: {
                subnetwork: output<string>
            }
        ]

When some instance is finally created, it becomes

networkInterfaces
[
  {
    "accessConfigs": [],
    "aliasIpRanges": [],
    "name": "nic0",
    "network": "<https://www.googleapis.com/compute/v1/projects/some-project/global/networks/vpc-network-default-b803ef2>",
    "networkIp": "10.122.0.3",
    "subnetwork": "<https://www.googleapis.com/compute/v1/projects/some-project/regions/europe-west1/subnetworks/vpc-subnetwork-default-bab788a>",
    "subnetworkProject": "some-subnetwork"
  }
]

How can I ask pulumi to wait for the value, even though the key is not present yet? Or how should I reference it properly?

When you say

initiate the stack

and then

when some instance is finally created

are you referring to the preview part of a

pulumi up

as that first bit and the actual deployment as the second bit? If so, pulumi preview is not able to show actual values for resource properties since it doesn’t know them yet. Once you let it deploy then it’s able to show the properties. Regardless, if you use outputs from one resource as inputs to another resource, Pulumi will manage the dependencies.

Well, the problem is that the preview throws the error that ‘networkIp’ key is not found.

Oh, sorry I see what you’re saying now. Have you tried using

.apply()

to essentially tell Pulumi the answer is coming later: https://www.pulumi.com/docs/intro/concepts/programming-model/#outputs

Yeah, I did. I tried something I do very often in my projects: Output.all(dbs_instance_pulumi_objects).apply(lambda x: x[0].network_interfaces[0][“networkIp”]), but it doesn’t work in this case, that’s why I brought up this topic. Sorry that I do not have a proper formatting, I am on my phone now.