Multi-Tenant Isolation

How STOA ensures complete tenant isolation and security.

Tenant Isolation Model

STOA implements a hard multi-tenancy model with strict isolation at multiple layers.

Isolation Layers

1. Kubernetes Namespace Isolation

Each tenant operates in a dedicated namespace:

apiVersion: v1
kind: Namespace
metadata:
  name: tenant-acme
  labels:
    stoa.io/tenant-id: acme
    stoa.io/tier: enterprise

Benefits:

• Resource isolation
• RBAC boundaries
• Network policy enforcement
• Resource quota limits

2. Network Isolation

Network policies prevent cross-tenant communication:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: tenant-isolation
  namespace: tenant-acme
spec:
  podSelector: {}
  policyTypes:
  - Ingress
  - Egress
  ingress:
  - from:
    - namespaceSelector:
        matchLabels:
          stoa.io/tenant-id: acme

3. Gateway Isolation

Each tenant gets dedicated Kong Gateway instance:

• Isolated routing rules
• Separate plugin configurations
• Independent rate limiting
• Tenant-specific certificates

4. Authentication Isolation

Keycloak multi-realm architecture:

• One realm per tenant
• Isolated user stores
• Separate client configurations
• Independent token validation

5. Data Isolation

• Tenant-specific databases or schemas
• Encrypted at rest
• Separate backup policies
• Audit logging per tenant

Resource Quotas

Each tenant has resource limits:

apiVersion: v1
kind: ResourceQuota
metadata:
  name: tenant-quota
  namespace: tenant-acme
spec:
  hard:
    requests.cpu: "10"
    requests.memory: 20Gi
    persistentvolumeclaims: "5"
    services.loadbalancers: "2"

Security Boundaries

Pod Security Standards

apiVersion: v1
kind: Namespace
metadata:
  name: tenant-acme
  labels:
    pod-security.kubernetes.io/enforce: restricted
    pod-security.kubernetes.io/audit: restricted
    pod-security.kubernetes.io/warn: restricted

Service Mesh Integration (Future)

• Mutual TLS between services
• Traffic encryption
• Policy-based access control
• Observability per tenant

Tenant Tiers

STOA supports different tenant tiers:

Tier	Resources	Features	SLA
Free	Limited	Basic APIs	Best effort
Starter	Moderate	APIs + Tools	99%
Business	High	Full platform	99.9%
Enterprise	Custom	White-label	99.95%

Monitoring & Observability

Per-tenant metrics:

• API request rates
• Error rates
• Latency percentiles
• Resource utilization
• Cost attribution

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🚧 Coming Soon: Tenant migration procedures, backup/restore guides, and compliance certifications.