set ignore_read for noRemoveDataDisk

[edwardmedia]

Fixes hashicorp/terraform-provider-google#8216

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Release Note Template for Downstream PRs (will be copied)

notebooks: fixed permadiff on noRemoveDataDisk for `google_notebooks_instance`

[modular-magician]

Hello! I am a robot who works on Magic Modules PRs.

I have detected that you are a community contributor, so your PR will be assigned to someone with a commit-bit on this repo for initial review.

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@melinath, please review this PR or find an appropriate assignee.

[modular-magician]

Hi! I'm the modular magician. Your PR generated some diffs in downstreams - here they are.

Diff report:

Terraform GA: Diff ( 2 files changed, 4 insertions(+), 11 deletions(-))
Terraform Beta: Diff ( 2 files changed, 4 insertions(+), 11 deletions(-))

[modular-magician]

I have triggered VCR tests based on this PR's diffs. See the results here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=167150"

[modular-magician]

I have triggered VCR tests in RECORDING mode for the following tests that failed during VCR: TestAccDataSourceGoogleServiceAccountIdToken_impersonation|TestAccActiveDirectoryDomainTrust_activeDirectoryDomainTrustBasicExample|TestAccApigeeOrganization_apigeeOrganizationCloudFullTestExample|TestAccCloudRunService_cloudRunServiceMultipleEnvironmentVariablesExample You can view the result here: "https://ci-oss.hashicorp.engineering/viewQueued.html?itemId=167240"

[melinath]

Hi Edward! I'm not familiar with this resource, so please bear with me :-)

My understanding is that ignore_read is primarily intended for situations where the return value isn't useful for some reason (like secrets). It seems like it would also prevent a permadiff in this case - but I'm concerned that we might be ignoring a diff that is real and the result of some other bug. I.e. if the value isn't being set correctly remotely, why is that? Is it safe to ignore?

The user also reported their main concern being that updating metadata or no_remove_data_disk caused the instance to be destroyed and recreated. It seems like the current PR does not address that issue - is that correct?

[edwardmedia]

@melinath the key problem here is API does not return no_remove_data_disk (not in the response), thus its state was not updated accordingly. Setting it with ignore_read will force to sync its state with the config, which could avoid the diff.
During my test, I am not able to see the diff in metadata.

[melinath]

Gotcha - that makes sense! Looking at the API and comparing it to the terraform.yaml file, it seems like all the "input only" fields have been marked ignore_read. That seems like it's an API bug to not let us read those fields out but I guess that's how it is 😂 thanks :-)

(Also since no_remove_data_disk is input only, it makes sense that changing it would force new.)

This LGTM, though it would be nice to have a test that would have caught this issue.