watch deletes

synced-pool.go

@@ -10,6 +10,7 @@ import (
 
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promauto"
+	"k8s.io/apimachinery/pkg/watch"
 )
 
 type Quorum interface {
@@ -183,18 +184,29 @@ func NewSyncedPool(local *GrainLocalPool, hostname string, discovery Discovery)
 				log.Printf("Error discovering hosts: %v", err)
 				return
 			}
-			for host := range ch {
-				if pool.IsKnown(host) || host == "" {
+			for chng := range ch {
+				if chng.Host == "" {
 					continue
 				}
-				go func(h string) {
-					log.Printf("Discovered host %s, waiting for startup", h)
-					time.Sleep(time.Second)
-					err := pool.AddRemote(h)
-					if err != nil {
-						log.Printf("Error adding remote %s: %v", h, err)
+				known := pool.IsKnown(chng.Host)
+				if chng.Type == watch.Added && !known {
+					go func(h string) {
+						log.Printf("Discovered host %s, waiting for startup", h)
+						time.Sleep(time.Second)
+						err := pool.AddRemote(h)
+						if err != nil {
+							log.Printf("Error adding remote %s: %v", h, err)
+						}
+					}(chng.Host)
+				} else if chng.Type == watch.Deleted && known {
+					log.Printf("Host removed %s, removing from index", chng.Host)
+					for _, r := range pool.remotes {
+						if r.Host == chng.Host {
+							pool.RemoveHost(r)
+							break
+						}
 					}
-				}(host)
+				}
 			}
 		}()
 	} else {