Auto-Sync RAG Pipeline: GCS Events to Vertex AI RAG Engine with Terraform ⚡

Vertex AI RAG Engine doesn't auto-sync when documents change. Here's how to build an event-driven pipeline with Eventarc, Cloud Functions, and Pub/Sub batching to trigger ImportRagFiles automatically using Terraform. You've built your RAG Engine corpus, imported files from GCS, and tested retrieval with Gemini. Then someone uploads new documents to the bucket and... nothing happens. The corpus still returns stale results. Vertex AI RAG Engine doesn't watch your GCS bucket for changes. You need to call ImportRagFiles whenever documents are added or updated. This post builds the event-driven pipeline with Terraform: GCS object events flow through Eventarc to a Cloud Function (2nd gen) that triggers the import. A Pub/Sub-based batching layer prevents redundant imports when multiple files land at once. 🎯 🏗️ Architecture Overview GCS Bucket (docs added/updated/deleted) ↓ Eventarc (object.finalize / object.delete) Cloud Function 2nd Gen (calls ImportRagFiles) ↓ On failure Cloud Logging + Ale