Handling non-existent GCP VM during Pulumi state deletion?

Question

Pulumi · Accepted Answer

In Pulumi, when a resource that was created by Pulumi and part of its state is manually deleted (such as a Google Cloud VM), it can cause issues when running `pulumi destroy` or `pulumi up`. You might see an error like: `google-native:compute/v1:Instance 'instance-x' resource not found`.

To resolve this, you can use the `ignoreChanges` and `lifecycle` properties in your resource definition. The `ignoreChanges` property allows you to specify parts of the resource that Pulumi should ignore when detecting changes, and lifecycle's `protect` property, when set to `true`, safeguards the resource from accidental deletion.

Here is an example where I define a Google Cloud VM instance:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as gcp from "@pulumi/gcp";

const instance = new gcp.compute.Instance("instance", {
    machineType: "e2-medium",
    bootDisk: {
        initializeParams: {
            imageFamily: "ubuntu-1804-lts",
            imageProject: "gce-uefi-images",        
        },
    },
    networkInterfaces: [{
        network: "default",
    }],
    lifecyclePolicy: {
        ignoreChanges: ["all"],
        protect: true, 
    },
});
```
In the code above, the `ignoreChanges` property is set to `all`, which means all changes to this resource will be ignored, and the `protect` property is set to `true` to prevent accidental deletion.

If a VM has been deleted manually, and you just want to get your Pulumi stack back to a clean state, you can remove references to the resource in your Pulumi code and then run `pulumi refresh`, which will align the Pulumi state with the actual state of the infrastructure.

Please note that the `lifecyclePolicy` and `ignoreChanges` parameters have a purpose of protecting infrastructure from accidental changes or deletion but they won't recreate an already deleted resource.

Your final program may look something like:

```typescript
import * as pulumi from "@pulumi/pulumi";
import * as gcp from "@pulumi/gcp";

// Create a GCP resource (Storage Bucket)
const mybucket = new gcp.storage.Bucket("my-bucket");

// Export the bucket selfLink
export const bucketSelfLink = mybucket.selfLink;
```
This program creates a Google Cloud Storage bucket and exports the selfLink. In this revised program, the VM instance resource is removed, so a `pulumi up` or `pulumi refresh` won't fail. Please make sure the remaining resources in the program are intact in your GCP project.

Find more details for GCP resource in Pulumi from [here](https://www.pulumi.com/registry/packages/gcp/).

Remember to replace `"my-bucket"` with an appropriate globally unique name for your bucket. If you remove the bucket, please also remove the exported `bucketSelfLink` line.