A team uses Spinnaker on GKE for deployment. They notice that deployments are taking too long because of manual judgment gates. They want to automatically approve deployments if the canary analysis passes predefined thresholds. What Spinnaker feature should they use?
ACA with Kayenta automates canary evaluation based on metrics thresholds.
Why this answer
Spinnaker's Automated Canary Analysis (ACA) feature allows teams to define canary analysis thresholds and automatically promote or roll back deployments based on the analysis results, eliminating the need for manual judgment gates. This directly addresses the requirement to automatically approve deployments when predefined thresholds are met, without human intervention.
Exam trap
The trap here is that candidates may confuse the Policy Engine (OPA) with automated approval logic, but OPA is for policy enforcement (e.g., 'only deploy from master branch'), not for statistical canary analysis and automated promotion.
How to eliminate wrong answers
Option A is wrong because automated rollback is a reactive mechanism that reverts a deployment after a failure is detected, not a proactive feature to automatically approve deployments based on canary analysis. Option B is wrong because the Policy Engine with OPA (Open Policy Agent) is used for enforcing governance and compliance policies (e.g., restricting which accounts can deploy), not for automating canary analysis approvals. Option C is wrong because Pipeline Expressions are used for dynamic parameterization and conditional logic within pipeline stages, but they cannot perform the statistical analysis of canary metrics required for automated approval.