I m continuing to struggle with stack references Following u

Question

I m continuing to struggle with stack references Following up on this thread <https pulumi community slack com archives CCWP5TJ5U p1595004364263000> I ve adopted the recommended `ApplyStringArray` and `ApplyString` functions to the outputs from the stack reference but trying to create an instance using a security group and subnet from the stack reference fails I guess it s defaulting to the first subnet in the default VPC and not using my subnet at all Code in thread below

salmon-account-74572 · Answer

I have a StackReference ```ref err = pulumi NewStackReference ctx user project stack nil if err = nil return err ``` Then I have this code to pull out the first subnet from an array of subnets created by the first stack ``` privSubnets = ref GetOutput pulumi String ref ApplyStringArray func out interface string var res string if out = nil for v = range out interface res = append res v string return res Get the ID of the first public subnet privSubnet0 = privSubnets ApplyString func a string string var res string if len a gt 0 res = a 0 return res ``` When I try to use `privSubnet0` to create an instance it must have a nil value because Pulumi tries to create the instance in a subnet in the default VPC which is completely wrong So what am I missing here

lemon-agent-27707 · Answer

what s the output of `pulumi stack output` for the original stack the one used to construct the stackref user proj stack

salmon-account-74572 · Answer

```Current stack outputs 16 OUTPUT VALUE EIP amiId ami 0288fa05d2ca8b5c7 bastionInstanceId i 0b93a76f7d1db768f bastionSecGrpId sg 0045840efd05c2db3 defaultRoute rtb 0a55c701f0d9bccb4 gatewayId igw 045fa2082d3efcd1e inetRoute r rtb 0a55c701f0d9bccb41080289494 k8sSecGrpId sg 0a4687591102705da natGateway nat 027db1764b3ad56a1 nodeSecGrpId sg 06648ddf8796bf63c numOfAZs 3 privRouteTableAssocIds rtbassoc 0db084e8424e969c2 rtbassoc 068e695773ce5bc7a rtbassoc 03da8e12e6db0ef47 privRouteTableId rtb 090cc2bd626d9f5e9 privSubnetIds subnet 0484737a31b183d10 subnet 0db65b831d7dc5603 subnet 0a7e23caa1a74d92e pubSubnetIds subnet 0a1b1395860d29849 subnet 00865b0cc48b28a77 subnet 04e8dfbb0e7eba4cf vpcId vpc 0e9bf44c8efd1133b``` All the outputs seem valid

lemon-agent-27707 · Answer

Can you share the error output you re seeing and the code that creates the uses `privSubnet0`

salmon-account-74572 · Answer

Yep Here s the error output ``` error Error launching source instance InvalidParameter Security group sg 06648ddf8796bf63c and subnet subnet 13f5c17b belong to different networks status code 400 request id dbdce577 3acc 4134 821d b1d17eb7a84d``` The referenced subnet ID is in the default VPC not the VPC created by the referenced stack Here s the code that references `privSubnet0` ``` controlPlane err = ec2 NewInstance ctx controlplane amp ec2 InstanceArgs Ami pulumi String amiID Id InstanceType pulumi String m5a large AssociatePublicIpAddress pulumi Bool false KeyName pulumi String keyPair SubnetId privSubnet0 VpcSecurityGroupIds pulumi StringArray nodeSecGrp Tags pulumi StringMap Name pulumi String controlplane ``` Note that `nodeSecGrp` used in the code above is the result of a stack reference and is working fine

lemon-agent-27707 · Answer

< salmon account 74572> is this the exact code you used ```ref GetOutput pulumi String ref ``` Should this use the name of your output instead ```ref GetOutput pulumi String privSubnetIds ```

salmon-account-74572 · Answer

Doh You re right I was referencing an non existent output Can t believe I missed that hangs his head in shame

salmon-account-74572 · Answer

And now it works as expected

lemon-agent-27707 · Answer

Awesome glad to hear it s working Copy paste bites us all Eventually it would be nice to have some strongly typed way to do stack outputs and references