Stateful Middleware using Key Value Store

Sometimes middleware need to keep track of state to be useful. In this example, we extend the Middleware example with another middleware that requires a Key Value Store.

Now if a client sends more than 10 requests in one second, Shield will automatically send a 429 Too Many Requests response. Note that we’ve placed the rate limiting middleware in front of the auth middleware, so that even requests that do not have the appropriate authentication will be rate limited.

application.conf

shield {
  domain-watcher: StaticDomainWatcher
  domains: [
    {
      domain-name: "api.example.org"
      middleware-chain: [
        {id: rate_limit, sla: 50ms, builder: BucketRateLimitBuilder},
        {id: auth, sla: 1s, builder: ApiKeyAuthBuilder}
      ]
      middleware: {
        auth: {
          header-name: "auth-key",
          allowed: "secret_key",
          case-sensitive: false
        }
        rate_limit: {
          bypass-header: "",
          calls-per: 10
          per-seconds: 1
          kvstore: "redis_kv"
        }
      }
      listeners: []
      listener-config: {}
      kvstores: {
        redis_kv: {
          type: "redis"
          url: "redis://127.0.0.1:6379"
        }
      }
      ignoreExtensions: []
      log: {
        request-headers: []
        response-headers: []
      }
      upstream-weighting: {
        step-count: 10
        step-duration: 3 seconds
      }

      upstream-watcher: StaticUpstreamWatcher
      upstreams: [
        {"serviceType": "swagger2", "serviceLocation": "https://example.com"},
        {"serviceType": "swagger2", "serviceLocation": "https://example.net"}
      ]
    }
  ]
}

Getting Started