Adding Listeners

In the Stateful Middleware example, we set up Shield to start doing some heavy lifting. However, it’s hard to appreciate our work if we can’t keep track of what Shield has done.

To fix that, let’s add a listener that write request/response log information to stdout. We’ve also updated Shield’s logger to capture the User-Agent header of the request so we can see what devices use our site.

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: [
        {id: log_console, builder: ConsoleLogBuilder}
      ]
      listener-config: {
        log_console: {
          // ConsoleLogBuilder doesn't take any config
        }
      }
      kvstores: {
        redis_kv: {
          type: "redis"
          url: "redis://127.0.0.1:6379"
        }
      }
      ignoreExtensions: []
      log: {
        request-headers: ["User-Agent"]
        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