Reference Architectures & Operating in Production
Overview
The Architect-track course on how continuous authorization is actually deployed and operated. It covers the five-layer continuous-authorization reference architecture (identity assertion, context, policy evaluation, enforcement, unified audit), the five deployment topologies you choose between (sidecar, centralized, Enterprise-OPA masking, AI-MCP gateway with workload mTLS, and admission controller), the latency budgets each has to hold, the fail-mode decision that every enforcement point must make explicit (fail-closed versus fail-open), and how decision logging with decision_logs.mask turns runtime decisions into durable evidence. A runnable OPA lab models one production decision end to end: a fail-closed default and a masking-aware decision at an AI-MCP gateway.
Who this is for
Architects and senior platform or security engineers designing a continuous-authorization deployment, both EnforceAuth customers and open-source OPA/Enterprise OPA users. You should already understand how Writ governs and promotes signed bundles from Govern with Writ and how decision logs and decision_logs.mask produce compliance evidence from Decision Logs, Continuous Authorization & Compliance Evidence. This course assumes you can read and write Rego; the lab has you author policy rules.
Outcomes
By the end of this course you will be able to:
- Name the five layers of the continuous-authorization reference architecture and say what each contributes to a single decision, from SPIFFE identity assertion through unified audit.
- Choose among the sidecar, centralized, Enterprise-OPA masking, AI-MCP gateway (workload mTLS), and admission-controller topologies, and state the latency budget and tradeoff each carries.
- Decide, per enforcement point, whether it should fail closed or fail open, and justify the choice against blast radius and availability.
- Design a production decision policy with a fail-closed default and a masking-aware decision, and prove with
opa testthat the field the policy flags for redaction is the field the decision-log mask removes.
Lessons
- The five-layer continuous-authorization reference architecture
- Deployment topologies and latency budgets
- Fail modes: fail-closed versus fail-open in production
- Decision logging, masking, and replay in operations
Hands-on lab
This course includes a graded lab in lab/. It models the decision a Policy Decision Point returns for one production request at an AI-MCP gateway Policy Enforcement Point: an AI agent, carrying a SPIFFE workload identity over mutual TLS, asking to invoke a tool. The policy has a fail-closed default and a masking-aware decision: it names the sensitive field the audit layer must redact, and a system.log.mask policy removes exactly that field. The policy ships as a starter with the two authorizing reason rules stubbed behind a # TODO(learner) block. Clone the public labs repo and run:
git clone https://github.com/EnforceAuth/university-labs.git
cd university-labs
opa test courses/reference-architectures -v
The starter reports FAIL: 2/11. Implement the two reason rules in lab/policy.rego until it reports PASS: 11/11. Keep iterating until opa test is green.
Certification
Counts toward the Architect track and is required for it. Certification is a machine-graded practical: the assessment engine gives you a production decision scenario and runs your policy against a HIDDEN opa test suite you never see, checking that your default is fail-closed, that your allow rules match the scenario, and that every field you flag for redaction is actually masked. This lab is practice for that exam, not the exam itself.