[8.0.0] container: extend google_container_node_pool name_prefix max length to 31

[c2thorn]

What changed

• Updates expandNodePool in resource_container_node_pool.go.tmpl to use tpgresource.ReducedPrefixedUniqueId(p) (appending 9 characters) instead of id.PrefixedUniqueId(p) (appending 26 characters) when len(name_prefix) > 14.
• Adds a ValidateFunc to "name_prefix" in schemaNodePool capping maximum prefix length at 31 characters (31 + 9 = 40).
• Adds TestAccContainerNodePool_namePrefix_long to verify that name_prefix values longer than 14 characters provision successfully.
• Updates container_node_pool.html.markdown resource documentation and the v8.0.0 Upgrade Guide (version_8_upgrade.html.markdown).

Why

Fixes hashicorp/terraform-provider-google#8261. Previously, any name_prefix longer than 14 characters combined with the standard 26-character UUID suffix exceeded GKE's 40-character limit for NodePool.name, failing at apply time with HTTP 400. Following the precedent of compute instance templates (PR #11448), switching to the 9-character shortened suffix for prefixes > 14 extends the maximum allowed name_prefix length from 14 to 31 characters.

Verification

• Feature Acceptance Test: Executed TestAccContainerNodePool_namePrefix_long (len = 18) against live GKE API; PASSED (HTTP 200 OK, generated name length 27 <= 40).
• Version Upgrade Safety: Executed TestAccContainerNodePool_namePrefix (len = 6) with RELEASE_DIFF=true; PASSED with 0 plan diffs (No changes), confirming zero drift or recreation when upgrading existing 7.x resources to 8.0.0.

container: extended `name_prefix` max length from 14 to 31 characters for `google_container_node_pool` and `google_container_cluster.node_pool`

[modular-magician]

Hi there, I'm the Modular magician. I've detected the following information about your changes for commit 6fb0aff:

Diff report

Your PR generated the following diffs in downstream repositories:

Repository	Diff Link	Changes
google provider	View Diff	4 files changed, 58 insertions(+), 3 deletions(-)
google-beta provider	View Diff	4 files changed, 58 insertions(+), 3 deletions(-)
terraform-google-conversion	View Diff	1 file changed, 3 insertions(+)

Test report

Important

Manual Verification Required

VCR cannot automatically execute the following tests added in this PR. Please verify them manually:

🔴 TestAccContainerNodePool_namePrefix_long

Analytics

Total Tests	Passed	Skipped	Affected
321	303	15	3

Affected Service Packages

• container

Learn how VCR tests work

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Step 1: Replaying Mode

Action taken

Found 3 affected test(s) by replaying old test recordings. Starting RECORDING based on the most recent commit.

Click here to see the affected tests

• TestAccContainerCluster_regionalWithNodePool
• TestAccContainerNodePool_withHostMaintenancePolicy
• TestAccContainerNodePool_withReservationAffinityAnyReservationThenFail

View the replaying VCR build log

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Step 2: Recording Mode

Recording Mode	Replaying Rerun	Test Name
✅ Log	✅	TestAccContainerNodePool_withReservationAffinityAnyReservationThenFail
❌ Error · Log	-	TestAccContainerCluster_regionalWithNodePool
❌ Error · Log	-	TestAccContainerNodePool_withHostMaintenancePolicy

Caution

Issues requiring attention before PR completion

🔴 Manual Verification Required: New tests were added that are skipped in presubmit tests. See the "Manual Verification Required" section at the top for details.

🔴 Initial Recording Failed: Some tests failed during the recording step. See the table above for details.

Please address these issues to complete your PR. If you believe these detections are incorrect or unrelated to your change, please raise the concern with your reviewer.

View the recording VCR build log or the debug logs folder for detailed results.

@c2thorn VCR tests complete for 6fb0aff!