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

pkg/cfg/cluster.go

@@ -17,10 +17,10 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
 package cfg
 
 import (
-	"context"
 	"crypto/tls"
 	"errors"
 	"fmt"
+	"net"
 	"net/http"
 	"os"
 	"strings"
@@ -185,42 +185,24 @@ func (conf *Config) SwitchCluster(name string) error {
 
 // We do NOT  use go-elasticsearch to check  for cluster reachability,
 // because  at this  stage,  auth  may not  have  been configured.  So
-// instead we just connect to  the cluster using plan net/http, ignore
-// HTTP response status and return true if we could just reach ith
+// instead we just connect to  the cluster using plan net/tcp
 func (cluster *Cluster) IsReachable() (bool, error) {
-	ctx, cancel := context.WithTimeout(
-		context.Background(),
-		time.Duration(500)*time.Millisecond)
-	defer cancel()
+	timeout := 500 * time.Millisecond
 
-	req, err := http.NewRequestWithContext(
-		ctx,
-		"GET",
-		cluster.Uri,
-		nil,
-	)
+	url := strings.TrimPrefix(strings.TrimPrefix(cluster.Uri, "https://"), "http://")
 
+	host := strings.Split(url, "/")
+
+	if !strings.Contains(host[0], ":") {
+		host[0] += ":443"
+	}
+
+	conn, err := net.DialTimeout("tcp", host[0], timeout)
 	if err != nil {
 		return false, err
 	}
 
-	client := &http.Client{Transport: &http.Transport{
-		TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
-	}}
-
-	resp, err := client.Do(req)
-
-	if err != nil {
-		return false, err
-	}
-
-	if resp != nil {
-		// at this  stage we do not care if  the elasticsearch cluster
-		// accepts our request or if it's misconfigured in some way
-		return true, nil
-	}
-
-	return false, nil
+	return true, conn.Close()
 }
 
 func (conf *Config) SetupES() error {

pkg/cfg/config.go

@@ -28,7 +28,7 @@ import (
 )
 
 const (
-	Version string = `v0.0.24`
+	Version string = `v0.0.25`
 )
 
 var (
@@ -137,6 +137,18 @@ func (conf *Config) Init() error {
 		return err
 	}
 
+	if err := conf.determineDefaultCluster(); err != nil {
+		return err
+	}
+
+	conf.HaveJQ = isJQinstalled()
+
+	conf.PrintDebug()
+
+	return nil
+}
+
+func (conf *Config) determineDefaultCluster() error {
 	if conf.CurrentCluster != "" {
 		// -C specified, set current cluster explicitly, no matter what the config says
 		current, exists := conf.Clusters[conf.CurrentCluster]
@@ -172,10 +184,6 @@ func (conf *Config) Init() error {
 		}
 	}
 
-	conf.HaveJQ = isJQinstalled()
-
-	conf.PrintDebug()
-
 	return nil
 }