Fix rds db param group default

[VenelinMartinov]

In #3638 - we introduced a diff customizer to change the schema as an alternative to patching. The change does not pass InternalValidate but because of pulumi/pulumi-terraform-bridge#1852 it was not flagged up.

After turning InternalValidate back on (pulumi/pulumi-terraform-bridge#1852) we discovered an issue with this parameter:

make tfgen_no_deps
(cd provider && go build -p 2 -o /Users/vvm/code/pulumi-aws/bin/pulumi-tfgen-aws -ldflags "-X github.com/pulumi/pulumi-aws/provider/v6/pkg/version.Version=6.29.1+dirty" github.com/pulumi/pulumi-aws/provider/v6/cmd/pulumi-tfgen-aws)
/Users/vvm/code/pulumi-aws/bin/pulumi-tfgen-aws schema --out provider/cmd/pulumi-resource-aws
Errors occurred: [InternalValidate: Internal validation of the provider failed! This is always a bug
with the provider itself, and not a user issue. Please report
this bug:

resource aws_db_parameter_group: apply_method: Default must be nil if computed]
make: *** [tfgen_no_deps] Error 255

This should fix it by also setting the Default to nil in the schema.

To keep the current behaviour, we set the Default in the pulumi overlay instead.

[github-actions]

Does the PR have any schema changes?

Does the PR have any schema changes?

Looking good! No breaking changes found.
No new resources/functions.

Maintainer note: consult the runbook for dealing with any breaking changes.

[github-actions]

Is README.md missing any configuration options?

assumeRoleWithWebIdentity not found in Configuration section
customCaBundle not found in Configuration section
defaultTags not found in Configuration section
ec2MetadataServiceEndpoint not found in Configuration section
ec2MetadataServiceEndpointMode not found in Configuration section
httpProxy not found in Configuration section
httpsProxy not found in Configuration section
ignoreTags not found in Configuration section
noProxy not found in Configuration section
retryMode not found in Configuration section
s3UsEast1RegionalEndpoint not found in Configuration section
sharedConfigFiles not found in Configuration section
skipRequestingAccountId not found in Configuration section
stsRegion not found in Configuration section
tokenBucketRateLimiterCapacity not found in Configuration section
useDualstackEndpoint not found in Configuration section

Please add a description for each of these options to README.md. Details about them can be found in either the upstream docs or schema.json.

[VenelinMartinov]

I wonder why we didn't generate the defaults in the sdk before - this PR just moves the defaults from the TF schema to the pulumi overlay. IMO this is a better UX for the sdks, does anyone know why they didn't show up before?

[iwahbe]

I believe it depends on how the defaults are applied. We can't always see inside TF providers to find the defaults they supply.

[iwahbe]

I'm having trouble understanding this PR.

Is this a bug we introduced in AWS in a patch, and if so can we just fix the patch? If not, does this imply that the upstream schema is invalid, and if so can we submit an upstream patch instead?

[VenelinMartinov]

The context is this: #3638 - we introduced a diff customizer to change the schema as an alternative to patching. The change does not pass InternalValidate but because of pulumi/pulumi-terraform-bridge#1852 it was not flagged up.

This PR corrects the change to make the schema pass InternalValidate

I don't believe we can submit a PR upstream as the change is pulumi-specific and different to the TF behaviour.

[t0yv0]

Nice this looks like it's testing the case where the default might kick in.

[t0yv0]

Looks like this compensates for the patch. Very nice.

[t0yv0]

🚢

[t0yv0]

Yes @iwahbe the alternative here would be to rework #2442 fix with patching, instead of a diff customizer, but as things stand this change here is the lightest-way step forward, so I think this is good for now.