ADR-019: MCP Cross-Validation Post-Registry-Publish
- Status: Proposed
- Date: 2026-02-27
- Deciders: Cloud Architect, QA Engineer
- Migrated from: ADR-REG-005
What
Define the validation procedure for confirming Registry ingestion after the v1.0.4 tag publish completes. Validation covers the public Terraform Registry API, module detail endpoint, and Terraform Cloud workspace webhook delivery.
Why
Registry propagation is asynchronous. The [release] pipeline job completes when gh release create returns, but Registry ingestion (triggered by TFC VCS webhook) may take up to 5 minutes. Without explicit post-publish validation, a silent ingestion failure (e.g., malformed README.md, missing required files) would go undetected.
When
After ADR-018 pipeline completes (release job PASS). Execute validation within 10 minutes of tag push.
How
API Validation
# Confirm v1.0.4 appears in version list
curl -s https://registry.terraform.io/v1/modules/oceansoft/iam-identity-center/aws \
| jq '.versions[].version'
# Expected: "1.0.4" in output
# Confirm module detail is populated (not 404)
curl -s https://registry.terraform.io/v1/modules/oceansoft/iam-identity-center/aws/1.0.4 \
| jq '{source: .source, version: .version, published_at: .published_at}'
Browser Validation
https://registry.terraform.io/modules/oceansoft/iam-identity-center/aws
Confirm: version selector shows 1.0.4, documentation tab renders, inputs/outputs tab populated.
Terraform Cloud Validation (if VCS connected)
app.terraform.io/app/oceansoft/ -> Workspace -> VCS -> verify webhook delivered
Evidence
API responses saved to:
tmp/terraform-aws/cost-reports/registry-validation-v1.0.4-YYYY-MM-DD.json
Failure Response
| Failure | Response |
|---|---|
| v1.0.4 not in version list after 10 minutes | Check TFC VCS webhook delivery; re-push tag if webhook missed |
| Module detail 404 | Check README.md and main.tf exist in module root; registry requires them |
| Inputs/outputs tab empty | Check outputs.tf is present and non-empty |
Consequences
Benefits
- Silent ingestion failures are caught before consumers attempt to use v1.0.4
- API validation commands are reproducible — QA engineer can re-run at any time
Tradeoffs
- 5-10 minute wait after tag push before validation is meaningful
Related ADRs
- ADR-018: pre-flight gate that must complete before this ADR's validation runs
Coordination Evidence
- Cloud Architect log:
tmp/terraform-aws/coordination-logs/cloud-architect-2026-02-27-adr-cost-tags.json