GCP Authentication & Authorization

Overview

Authentication answers "who are you?" — authorization (IAM) answers "what can you do?" Google Cloud uses three concepts together: Principals (user accounts, service accounts, federated identities), short-lived tokens issued by metadata servers or the Service Account Credentials API, and IAM Allow Policies that bind principals to predefined or custom roles on resources.

The right pattern depends on where the code runs and who is calling.

Instructions

Decision Matrix