tune cluster ls: parallized and use tcp connect instead of https (#63)

pkg/es/cluster.go

@@ -31,44 +31,62 @@ import (
 
 type ClusterIndices map[string]map[string]*types.IndicesRecord
 
-func ClusterList(conf *cfg.Config) error {
-	table := printer.NewTable(conf, 5, len(conf.Clusters))
+type clusterReachable struct {
+	reachable bool
+	err       error
+}
 
+func ClusterList(conf *cfg.Config) error {
+	var mu sync.Mutex
+	var wg sync.WaitGroup
+	reachable := make(map[string]clusterReachable, len(conf.Clusters))
+
+	// check endpoints in parallel to speed things up
+	for name, cluster := range conf.Clusters {
+		wg.Add(1)
+
+		go func() {
+			defer wg.Done()
+			online, err := cluster.IsReachable()
+
+			mu.Lock()
+			reachable[name] = clusterReachable{reachable: online, err: err}
+			mu.Unlock()
+		}()
+	}
+
+	wg.Wait()
+
+	table := printer.NewTable(conf, 5, len(conf.Clusters))
 	table.Addheaders("cluster", "uri", "reachable", "current", "error")
 
 	idx := 0
 
 	for name, cluster := range conf.Clusters {
-		reachable := "no"
+		reachableStr := "no"
 		current := "no"
 		errmsg := ""
 
-		online, err := cluster.IsReachable()
-
-		if online {
-			reachable = printer.Colorize(conf, "green", "reachable")
+		if reachable[name].reachable {
+			reachableStr = printer.Colorize(conf, "green", "reachable")
 		}
 
 		if cluster.Default {
 			current = printer.Colorize(conf, "green", "yes")
 
-			if !online {
-				reachable = printer.Colorize(conf, "red", "no")
-				errmsg = err.Error()
+			if !reachable[name].reachable {
+				reachableStr = printer.Colorize(conf, "red", "no")
+				errmsg = reachable[name].err.Error()
 			}
 		}
 
-		table.Entries[idx] = []string{name, cluster.Uri, reachable, current, errmsg}
+		table.Entries[idx] = []string{name, cluster.Uri, reachableStr, current, errmsg}
 		idx++
 	}
 
 	table.Sort()
 
-	if err := table.Print(); err != nil {
-		return err
-	}
-
-	return nil
+	return table.Print()
 }
 
 // We're using goroutines  here to parallelize API  requests, since we