working on typescript , how can i validate if resouces exists before try to create it. ?

Within one stack, or within one AWS Account + Region?

aws account + region

You can accomplish this with an exhaustive use of get functions - eg https://www.pulumi.com/registry/packages/aws/api-docs/ec2/getvpc/ but I'd suggest this may not be optimal. For resources where AWS does not enforce uniqueness ( like VPCs ), who cares if there is another with the same name? Within the scope of your stack, that should be irrelevant. If you want to enforce naming standards across an account, you should probably do that via some tag enforcement regiment.

Using the

get

functions for this doesn't work well. Consider that the resource doesn't exist, the stack will then create the resource. On subsequent runs, the

get

will find the resource, which will result in the resource getting deleted as you're fetching with

get

instead of with the standard resource object. A common strategy is to use multiple projects if you're in a situation where mulitple stacks depend on a common resource, then use stack references to pass the id around: https://www.pulumi.com/learn/building-with-pulumi/stack-references/

@dry-keyboard-94795 yeah you have to combine it with

import

IDs, personally I'd consider it an anti-pattern unless you have some specific import migration task you're trying to accomplish

so there is not easy way for it ?

Conditional creation, no. But depending on your needs, there are other strategies, such as using

import

to adopt an already existing resource; or stack references where you have common resources across multiple stacks

so it will look like this import * as pulumi from "@pulumi/pulumi"; import * as aws from "@pulumi/aws"; // Replace "vpc-abcde1234" with your actual VPC ID const vpcId = "vpc-abcde1234"; const vpc = pulumi.output(aws.ec2.getVpc({ id: vpcId }, { async: true })); let vpcIdVal : string; let publicSubnetIdsVal : string[]; // Extract 'vpcId' and 'publicSubnetIds' from Output<> type via 'apply' method vpc.apply(vpc => { vpcIdVal = vpc.id; // Assume 'publicSubnetIds' are stored as tags in the VPC publicSubnetIdsVal = vpc.tags["publicSubnetIds"].split(","); console.log(

VPC ID: ${vpcIdVal}

); console.log(

Public Subnet IDs: ${publicSubnetIdsVal}

); });

The

.apply

doesn't necessarily run until the end of the stack, so the values will likely not be set. Most resources will accept

Output

as parameters, so can use

vpc.id

directly

can you help with small code example 🙂

const vpcIdVal: Output<string> = vpc.id

Like this