TF: plan -refresh=false for google_compute_ha_vpn_gateway with gcs backend has resource replacement

[akshat-jindal-nit]

Bug: b/376368181
Issue: hashicorp/terraform-provider-google#19978
This particular change is the main culprit of this issue https://screenshot.googleplex.com/79xwUXBEcc5SYAg.
Looks like this issue start occurring from the release v5.40.0 https://screenshot.googleplex.com/367U6wou3dHnzaJ.

Release Note Template for Downstream PRs (will be copied)

bug: fixed an issue where `terraform plan -refresh=false` with `google_compute_ha_vpn_gateway.gateway_ip_version` would plan a resource replacement if a full refresh had not been run yet. Terraform now assumes that the value is the default value, `IPV4`, until a refresh is completed.

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[harshithpatte-g]

@akshat-jindal-nit can repro this issue with a test? Could we add that test?

[akshat-jindal-nit]

@akshat-jindal-nit can repro this issue with a test? Could we add that test?

@harshithpatte-g this particular change is related to terraform plan -refresh=false related changes. I think we don't write any particulars tests for it.
But this TestAccDataSourceComputeHaVpnGateway is running successfully as our changes are intended to impact the default_values only .

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[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 1 file changed, 4 deletions(-))
google-beta provider: Diff ( 1 file changed, 4 deletions(-))

[modular-magician]

Tests analytics

Total tests: 1069
Passed tests: 996
Skipped tests: 73
Affected tests: 0

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• compute

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[rileykarson]

Were you able to test manually to confirm the fix? I'm a bit confused why this works, because we're removing what is traditionally the mitigation for the issue here.

[akshat-jindal-nit]

Were you able to test manually to confirm the fix? I'm a bit confused why this works, because we're removing what is traditionally the mitigation for the issue here.

Yes I test it manually and this particular change is fixing this particular issue.

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@rileykarson This PR has been waiting for review for 3 weekdays. Please take a look! Use the label disable-review-reminders to disable these notifications.

[rileykarson]

Sorry, could you elaborate on how you've reproduced the issue? I continue to see it both before and after this change. Effectively, we assume that a refresh is performed after the upgrade- we'd resolve that with a StateUpgrader to infill the default value where it's null (but really, a full refresh would be better in case the live value is different).

[akshat-jindal-nit]

StateUpgrader

I perform these steps to reproduce the issue b/37636818

1. make a module with the 1st configuration (provider v5.16.0)
2. terraform init
3. terraform apply
4. change google provider version to v5.44.2
5. rm -f .terraform.lock.hcl
6. terraform init
7. terraform plan -refresh=false <--- the issue occurrs here
8. terraform plan <--- doesn't have changes
9. terraform apply <--- doesn't make any changes

By removing the defaulting logic, the fixed version of the function ensures that Terraform accurately reflects the actual state of the gateway_ip_version attribute in Google Cloud. This prevents the false positive change detection and avoids unnecessary resource replacements.

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[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 1 file changed, 118 insertions(+))
google-beta provider: Diff ( 1 file changed, 118 insertions(+))

[modular-magician]

Tests analytics

Total tests: 1073
Passed tests: 1000
Skipped tests: 73
Affected tests: 0

Click here to see the affected service packages

• compute

🟢 All tests passed!

View the build log

[rileykarson]

The code looks good and this works on my machine to solve the original bug- just waiting for generate + test to LGTM and merge.

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes:

Diff report

Your PR generated some diffs in downstreams - here they are.

google provider: Diff ( 1 file changed, 129 insertions(+))
google-beta provider: Diff ( 1 file changed, 129 insertions(+))

[modular-magician]

Tests analytics

Total tests: 1073
Passed tests: 1000
Skipped tests: 73
Affected tests: 0

Click here to see the affected service packages

• compute

🟢 All tests passed!

View the build log