more limits.Agent elaboration (#271)

controller/controller.go

@@ -88,9 +88,7 @@ func Run(inCfg *config.Config) error {
 				return errors.Wrap(err, "error creating limits agent")
 			}
 			ma.AddUsageSink(la)
-			if err := la.Start(); err != nil {
+			la.Start()
-				return errors.Wrap(err, "error starting limits agent")
-			}
 			defer func() { la.Stop() }()
 		}
 	}

controller/limits/agent.go

@@ -5,23 +5,56 @@ import (
 	"github.com/openziti/zrok/controller/store"
 	"github.com/openziti/zrok/controller/zrokEdgeSdk"
 	"github.com/sirupsen/logrus"
+	"time"
 )
 
 type Agent struct {
+	cfg   *Config
+	ifx   *influxReader
+	zCfg  *zrokEdgeSdk.Config
+	str   *store.Store
+	close chan struct{}
+	join  chan struct{}
 }
 
 func NewAgent(cfg *Config, ifxCfg *metrics.InfluxConfig, zCfg *zrokEdgeSdk.Config, str *store.Store) (*Agent, error) {
-	return &Agent{}, nil
+	return &Agent{
+		cfg:   cfg,
+		ifx:   newInfluxReader(ifxCfg),
+		zCfg:  zCfg,
+		str:   str,
+		close: make(chan struct{}),
+		join:  make(chan struct{}),
+	}, nil
 }
 
-func (a *Agent) Start() error {
+func (a *Agent) Start() {
-	return nil
+	go a.run()
 }
 
 func (a *Agent) Stop() {
+	close(a.close)
+	<-a.join
 }
 
 func (a *Agent) Handle(u *metrics.Usage) error {
 	logrus.Infof("handling: %v", u)
 	return nil
 }
+
+func (a *Agent) run() {
+	logrus.Info("started")
+	defer logrus.Info("stopped")
+
+mainLoop:
+	for {
+		select {
+		case <-time.After(a.cfg.Cycle):
+			logrus.Info("insepection cycle")
+
+		case <-a.close:
+			close(a.join)
+			break mainLoop
+		}
+	}
+}

controller/limits/config.go

@@ -8,6 +8,7 @@ type Config struct {
 	Environments int
 	Shares       int
 	Bandwidth    *BandwidthConfig
+	Cycle        time.Duration
 	Enforcing    bool
 }
 
@@ -74,5 +75,7 @@ func DefaultConfig() *Config {
 				},
 			},
 		},
+		Enforcing: false,
+		Cycle:     15 * time.Minute,
 	}
 }

controller/limits/influxReader.go

@@ -0,0 +1,18 @@
+package limits
+
+import (
+	influxdb2 "github.com/influxdata/influxdb-client-go/v2"
+	"github.com/influxdata/influxdb-client-go/v2/api"
+	"github.com/openziti/zrok/controller/metrics"
+)
+
+type influxReader struct {
+	idb      influxdb2.Client
+	queryApi api.QueryAPI
+}
+
+func newInfluxReader(cfg *metrics.InfluxConfig) *influxReader {
+	idb := influxdb2.NewClient(cfg.Url, cfg.Token)
+	queryApi := idb.QueryAPI(cfg.Org)
+	return &influxReader{idb, queryApi}
+}