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devopscritical PriorityID: k8s-gateway-v1-2-spiffe-workload-identity-attestation

Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants

Enforces strict zero-trust cryptographic workload identity verification between ingress gateways and internal mesh services using Kubernetes Gateway API v1.2 BackendTLSPolicy and SPIFFE SAN validation. Prevents perimeter-only token spoofing, cleartext internal hops, and unauthenticated downstream backend connections.

Prohibited Anti-Pattern: Cleartext Service Backend Routing and Insecure Trust-on-First-Use (TOFU) Gateway Forwarding

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---
description: Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants - Enforces strict zero-trust cryptographic workload identity verification between ingress gateways and internal mesh services using Kubernetes Gateway API v1.2 BackendTLSPolicy and SPIFFE SAN validation. Prevents perimeter-only token spoofing, cleartext internal hops, and unauthenticated downstream backend connections.
globs: deploy/**/*.yaml, k8s/**/*.yaml, infra/**/*.yaml, manifests/**/*.yaml, helm/**/*.yaml
alwaysApply: true
verified_by: "agentrules.org"
license: "CC-BY-4.0"
source: "https://agentrules.org/rules/k8s-gateway-v1-2-spiffe-workload-identity-attestation"
---

# Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants

> **Severity**: CRITICAL | **Category**: devops
> **Anti-Pattern Warning**: Cleartext Service Backend Routing and Insecure Trust-on-First-Use (TOFU) Gateway Forwarding

## System Constraints
You are a Principal Software Architect enforcing zero-trust networking through Kubernetes Gateway API v1.2 and SPIFFE/SPIRE Workload Identity Attestation. You must reject any configuration routing traffic to downstream backend services without an explicitly bound BackendTLSPolicy that validates cryptographic SPIFFE Subject Alternative Names (SANs) and dynamically attested CA trust bundles. Eliminate all cleartext cluster-internal backend routing, unvalidated SAN wildcards, and spoofable Layer 7 identity headers.

## Strict Guidelines
- Engineers MUST ALWAYS bind every HTTPRoute backend service to a Gateway API v1.2 `BackendTLSPolicy` enforcing dynamic mTLS origination.
- Engineers MUST NOT route gateway traffic directly to plain `Service` endpoints over insecure HTTP (port 80) without upstream SPIFFE cryptographic attestation.
- Engineers MUST validate the downstream workload's explicit SPIFFE ID SAN (`spiffe://<trust-domain>/ns/<namespace>/sa/<serviceaccount>`) within `spec.validation.hostname` or gateway-mesh security policies.
- Services MUST mount dynamic SPIFFE Workload API UNIX domain sockets via the SPIRE Agent CSI driver rather than storing static TLS certificates in Kubernetes Secrets.
- Gateway implementations MUST reject downstream TLS handshakes if the peer leaf certificate is not signed by an attested SPIRE trust bundle or if the SPIFFE ID does not match the strict authorized identity list.
- Components NEVER bridge perimeter authentication headers (such as `X-Forwarded-Client-Cert` or `X-Remote-User`) downstream unless cryptographic re-signing or SPIFFE client certificate projection is enforced at the Gateway boundary.

## Bad vs Good Implementations
### BackendTLSPolicy with Strict SPIFFE SAN Attestation vs Insecure Cleartext Routing

#### Bad Antipattern (AI Common Hallucination)
> **Why it fails**: This configuration routes requests across internal cluster networks in plaintext (port 8080) with zero identity verification. A compromised pod or sidecar in the network path can intercept, alter, or spoof traffic because neither mTLS nor SPIFFE identity attestation is enforced between the gateway and downstream pods.
```yaml
# INSECURE: Gateway API route directly forward traffic to backend Service
# over plaintext without BackendTLSPolicy mTLS and SPIFFE SAN verification.
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: payments-route
  namespace: production
spec:
  parentRefs:
    - name: edge-gateway
      namespace: gateway-infra
  rules:
    - matches:
        - path:
            type: PathPrefix
            value: /api/v1/payments
      backendRefs:
        - name: payments-service
          port: 8080
          weight: 100
```

#### Production Standard (Correct)
> **Standard**: The BackendTLSPolicy ensures the Gateway dynamically originates mTLS to the backend over port 8443. It cryptographically verifies the upstream workload's identity against the SPIRE-attested CA bundle and strictly validates the downstream SPIFFE Subject Alternative Name before routing traffic.
```yaml
# SECURE: Gateway API v1.2 BackendTLSPolicy enforces upstream dynamic TLS
# origination, validating the downstream pod's SPIFFE ID via attested CA bundle.
apiVersion: gateway.networking.k8s.io/v1
kind: HTTPRoute
metadata:
  name: payments-route
  namespace: production
spec:
  parentRefs:
    - name: edge-gateway
      namespace: gateway-infra
  rules:
    - matches:
        - path:
            type: PathPrefix
            value: /api/v1/payments
      backendRefs:
        - name: payments-service
          port: 8443
          weight: 100
---
apiVersion: gateway.networking.k8s.io/v1alpha3
kind: BackendTLSPolicy
metadata:
  name: payments-backend-tls
  namespace: production
spec:
  targetRefs:
    - group: ""
      kind: Service
      name: payments-service
  validation:
    caCertificateRefs:
      - group: ""
        kind: ConfigMap
        name: spire-bundle
    hostname: payments-service.production.svc.spiffe.cluster.local
```
Recommended MCP Servers (mcp-serverlist.com)

Equip agent with system tools to verify code for this stack.

Kubernetes Resource & CRD Validator MCP
Validates Kubernetes Gateway API v1.2 resources and dynamic schema constraints.
SPIRE Workload Attestation Controller MCP
Inspects SPIFFE trust bundles, registration entries, and dynamic identity sockets across nodes.
Recommended Agent Skills (askills.dev)

Ready-to-use executable skill functions tailored to this stack.

SPIRE CLI Attestation Verifier
Validates SVIDs, SPIFFE IDs, and dynamic x509 SAN extensions for target Kubernetes pods.
Gateway API Conformance Checker
Validates Gateway API v1.2 BackendTLSPolicy binding invariants and reference authorization.
Architectural Specification & Invariant Rationale

Architectural Invariant Design: Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants

Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants defines an industrial-grade behavioral standard for devops engineering. Enforces strict zero-trust cryptographic workload identity verification between ingress gateways and internal mesh services using Kubernetes Gateway API v1.2 BackendTLSPolicy and SPIFFE SAN validation. Prevents perimeter-only token spoofing, cleartext internal hops, and unauthenticated downstream backend connections. Modern software architectures require strict adherence to deterministic patterns to guarantee high availability, maintainability, and zero security vulnerabilities.

Framework Paradigm Shift & Drift MechanicsLLMs are trained on millions of open-source repositories containing outdated code, legacy idioms, and unpatched antipatterns. When coding assistants generate implementations for this stack, they default to common statistical tokens: Cleartext Service Backend Routing and Insecure Trust-on-First-Use (TOFU) Gateway Forwarding Without an explicit system instruction file, developers spend hours debugging silent failures.
Failure Modes & Production Blast Radius

Hazard Analysis: What Breaks Without This Rule

The following failure modes have been cataloged from hundreds of hours of production code reviews where AI assistants produced non-compliant implementations:

Failure ModeAI Symptom (The Anti-Pattern)SeverityProduction Impact & Remedy
AI Hallucination & Deprecation DriftCleartext Service Backend Routing and Insecure Trust-on-First-Use (TOFU) Gateway ForwardingCritical
Violating this industrial standard introduces regression bugs, security risks, and unexpected runtime failures in production.
Enforce explicit behavioral system directives across all AI coding assistants in your repository.
Silent Architecture InconsistencyAI assistants produce mixed paradigms across files, creating fragmented codebase conventions.Medium
Increases cognitive load during code reviews and leads to maintenance debt across engineering teams.
Pin project conventions in .cursor/rules, CLAUDE.md, and AGENTS.md so all team agents follow identical guardrails.
Architectural Directives in Detail

Step-by-Step Production Directives

Each rule constraint below is injected into the AI agent's system prompt to establish deterministic boundaries:

1

Engineers MUST ALWAYS bind every HTTPRoute backend service to a Gateway API v1.2 `BackendTLSPolicy` enforcing dynamic mTLS origination.

Engineers MUST ALWAYS bind every HTTPRoute backend service to a Gateway API v1.2 `BackendTLSPolicy` enforcing dynamic mTLS origination.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
2

Engineers MUST NOT route gateway traffic directly to plain `Service` endpoints over insecure HTTP (port 80) without upstream SPIFFE cryptographic attestation.

Engineers MUST NOT route gateway traffic directly to plain `Service` endpoints over insecure HTTP (port 80) without upstream SPIFFE cryptographic attestation.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
3

Engineers MUST validate the downstream workload's explicit SPIFFE ID SAN (`spiffe

Engineers MUST validate the downstream workload's explicit SPIFFE ID SAN (`spiffe://<trust-domain>/ns/<namespace>/sa/<serviceaccount>`) within `spec.validation.hostname` or gateway-mesh security policies.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
4

Services MUST mount dynamic SPIFFE Workload API UNIX domain sockets via the SPIRE Agent CSI driver rather than storing static TLS certificates in Kubernetes Secrets.

Services MUST mount dynamic SPIFFE Workload API UNIX domain sockets via the SPIRE Agent CSI driver rather than storing static TLS certificates in Kubernetes Secrets.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
5

Gateway implementations MUST reject downstream TLS handshakes if the peer leaf certificate is not signed by an attested SPIRE trust bundle or if the SPIFFE ID does not match the strict authorized identity list.

Gateway implementations MUST reject downstream TLS handshakes if the peer leaf certificate is not signed by an attested SPIRE trust bundle or if the SPIFFE ID does not match the strict authorized identity list.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
6

Components NEVER bridge perimeter authentication headers (such as `X-Forwarded-Client-Cert` or `X-Remote-User`) downstream unless cryptographic re-signing or SPIFFE client certificate projection is enforced at the Gateway boundary.

Components NEVER bridge perimeter authentication headers (such as `X-Forwarded-Client-Cert` or `X-Remote-User`) downstream unless cryptographic re-signing or SPIFFE client certificate projection is enforced at the Gateway boundary.

Rationale:AI models frequently generate unconstrained code here because statistical language distributions lack project-specific architectural context. Mandating this directive ensures that generated code adheres to verified industrial production requirements.
Enforcement:Integrated into the Agent Pack rule file. When Cursor, Claude Code, or Codex processes this prompt, it applies this constraint before emitting syntax.
Technical Questions & Answers

Frequently Asked Technical Questions

Common questions developers face when configuring AI coding assistants for this stack:

Q:Why is Kubernetes Gateway API v1.2 SPIFFE Workload Identity Attestation and Dynamic mTLS Invariants critical for AI coding assistants?

Enforces strict zero-trust cryptographic workload identity verification between ingress gateways and internal mesh services using Kubernetes Gateway API v1.2 BackendTLSPolicy and SPIFFE SAN validation. Prevents perimeter-only token spoofing, cleartext internal hops, and unauthenticated downstream backend connections. Without explicit behavioral boundaries, AI coding assistants (Cursor, Claude Code, Windsurf, Codex) rely on training data averages, which frequently produce deprecated, inefficient, or vulnerable code patterns.

Q:How does adopting this rule prevent AI hallucinations?

This rule explicitly declares what the AI must avoid (Cleartext Service Backend Routing and Insecure Trust-on-First-Use (TOFU) Gateway Forwarding) and prescribes verified positive examples. Grounding the LLM with negative and positive pairs eliminates guesswork.

Q:Which AI coding environments are supported?

This specification is multi-platform compatible: Cursor (.cursor/rules/*.mdc & .cursorrules), Anthropic Claude Code (CLAUDE.md), Windsurf (.windsurfrules), Codex / Cline (AGENTS.md), and GitHub Copilot (.github/copilot-instructions.md).

Q:Can I combine this rule with other technology stacks?

Yes. Use the Interactive Stack Builder or download an Agent Pack to merge this rule with other frontend, backend, database, security, and DevOps rules without syntax collision.

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