[Proposal] Tenant level config for different microservices

[vaivk369]

Tenant Configuration Management

Table: tenant_configs

CREATE TABLE tenant_configs (
  id UUID PRIMARY KEY,
  tenant_id TEXT NOT NULL,
  context TEXT NOT NULL,        -- e.g., 'storage', 'lms', 'assessment'
  config JSONB NOT NULL,        -- holds configuration as JSON
  version INTEGER DEFAULT 1,    -- optional versioning for rollback or evolution
  expires_at TIMESTAMPTZ,       -- optional expiry for temporary overrides
  created_at TIMESTAMPTZ DEFAULT now(),
  updated_at TIMESTAMPTZ DEFAULT now(),
  UNIQUE (tenant_id, context)
);

Example Config Values by Context

Storage (context = 'storage')

{
  "provider": "aws",
  "region": "us-east-1",
  "bucket": "tenant-abc-bucket",
  "accessKey": "AKIA...",  
  "secretKey": "abc..."     
}

LMS (context = 'lms')

{
  "enableCertificates": true,
  "defaultLanguage": "en",
  "theme": "light"
}

Assessment (context = 'assessment')

{
  "allowResume": true,
  "showCorrectAnswers": false,
  "timeLimitMinutes": 30
}

Events (context = 'events')

{
  "maxParticipants": 200,
  "reminderEmailTemplate": "default_reminder"
}

Access Patterns

API Endpoints

• GET /userservice/v1/tenant/configs?context=abc
• GET /tenant/:tenantId/configs
• GET /tenant/:tenantId/configs/:context
• POST /tenant/:tenantId/configs/:context

Service-Level Configuration Loader

@Injectable()
export class ConfigService {
  async getConfig(context: string, tenantId: string, orgId?: string) {
    const cacheKey = `config:${tenantId}:${orgId || 'default'}:${context}`;
    let config = await this.cache.get(cacheKey);

    if (!config) {
      config = await this.db.query(/* lookup logic with tenantId/context */);
      if (config?.sensitive) {
        config = decrypt(config);
      }
      validate(context, config);
      await this.cache.set(cacheKey, config, { ttl: 3600 });
    }

    return config;
  }
}

Loading Strategy

• Boot-time: Load during startup and refresh periodically.
• On-demand: Load per request and cache in Redis (preferred).

Schema Validation

Use libraries like ajv:

const schema = contextSchemas[context];
if (!ajv.validate(schema, config)) {
  throw new Error('Invalid config structure');
}

Audit Logging

CREATE TABLE tenant_config_audits (
  id UUID PRIMARY KEY,
  tenant_id TEXT NOT NULL,
  context TEXT NOT NULL,
  changed_by TEXT,
  old_config JSONB,
  new_config JSONB,
  changed_at TIMESTAMPTZ DEFAULT now()
);

Cache Invalidation

await redis.del(`config:${tenantId}:${orgId || 'default'}:${context}`);
await pubSub.publish('config.updated', { tenantId, context });

Best Practices

Concern	Best Practice
Sensitive values	Encrypt before storing
Redis security	Use TLS + AUTH + VPC/private access
Config TTL	Use short TTL (5–10 mins)
Org-level override	Fallback to org-level/global config
Schema validation	Validate using per-context JSON schema
Versioning	Add version column for rollback
Load strategy	Prefer on-demand with Redis cache

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