Dynamic Configuration Refactoring

old/provider/eureka/eureka.go

@@ -0,0 +1,92 @@
+package eureka
+
+import (
+	"io/ioutil"
+	"time"
+
+	"github.com/ArthurHlt/go-eureka-client/eureka"
+	"github.com/cenk/backoff"
+	"github.com/containous/flaeg/parse"
+	"github.com/containous/traefik/job"
+	"github.com/containous/traefik/old/log"
+	"github.com/containous/traefik/old/provider"
+	"github.com/containous/traefik/old/types"
+	"github.com/containous/traefik/safe"
+)
+
+// Provider holds configuration of the Provider provider.
+type Provider struct {
+	provider.BaseProvider `mapstructure:",squash" export:"true"`
+	Endpoint              string         `description:"Eureka server endpoint"`
+	RefreshSeconds        parse.Duration `description:"Override default configuration time between refresh" export:"true"`
+}
+
+// Init the provider
+func (p *Provider) Init(constraints types.Constraints) error {
+	return p.BaseProvider.Init(constraints)
+}
+
+// Provide allows the eureka provider to provide configurations to traefik
+// using the given configuration channel.
+func (p *Provider) Provide(configurationChan chan<- types.ConfigMessage, pool *safe.Pool) error {
+	eureka.GetLogger().SetOutput(ioutil.Discard)
+
+	operation := func() error {
+		client := eureka.NewClient([]string{p.Endpoint})
+
+		applications, err := client.GetApplications()
+		if err != nil {
+			log.Errorf("Failed to retrieve applications, error: %s", err)
+			return err
+		}
+
+		configuration, err := p.buildConfiguration(applications)
+		if err != nil {
+			log.Errorf("Failed to build configuration for Provider, error: %s", err)
+			return err
+		}
+
+		configurationChan <- types.ConfigMessage{
+			ProviderName:  "eureka",
+			Configuration: configuration,
+		}
+
+		ticker := time.NewTicker(time.Duration(p.RefreshSeconds))
+		pool.Go(func(stop chan bool) {
+			for {
+				select {
+				case t := <-ticker.C:
+					log.Debugf("Refreshing Provider %s", t.String())
+					applications, err := client.GetApplications()
+					if err != nil {
+						log.Errorf("Failed to retrieve applications, error: %s", err)
+						continue
+					}
+					configuration, err := p.buildConfiguration(applications)
+					if err != nil {
+						log.Errorf("Failed to refresh Provider configuration, error: %s", err)
+						continue
+					}
+					configurationChan <- types.ConfigMessage{
+						ProviderName:  "eureka",
+						Configuration: configuration,
+					}
+				case <-stop:
+					return
+				}
+			}
+		})
+		return nil
+	}
+
+	err := backoff.RetryNotify(operation, job.NewBackOff(backoff.NewExponentialBackOff()), notify)
+	if err != nil {
+		log.Errorf("Cannot connect to Provider server %+v", err)
+		return err
+	}
+	return nil
+}
+
+func notify(err error, time time.Duration) {
+	log.Errorf("Provider connection error %+v, retrying in %s", err, time)
+}