Fix CSI controller URL for IPv6 service hosts

frontend/csi/plugin.go

@@ -5,6 +5,7 @@ package csi
 import (
 	"context"
 	"fmt"
+	"net"
 	"os"
 	"runtime"
 	"strings"
@@ -42,6 +43,10 @@ const (
 	CSIAllInOne   = "allInOne"
 )
 
+func controllerRestURL(host, port string) string {
+	return "https://" + net.JoinHostPort(host, port)
+}
+
 type Plugin struct {
 	orchestrator  core.Orchestrator
 	activatedChan chan struct{}
@@ -262,7 +267,7 @@ func NewNodePlugin(
 		hostname = tridentconfig.ServerCertName
 	}
 
-	restURL := "https://" + hostname + ":" + port
+	restURL := controllerRestURL(hostname, port)
 	p.restClient, err = controllerAPI.CreateTLSRestClient(restURL, caCert, clientCert, clientKey)
 	if err != nil {
 		return nil, err
@@ -354,7 +359,7 @@ func NewAllInOnePlugin(
 			break
 		}
 	}
-	restURL := "https://" + tridentconfig.ServerCertName + ":" + port
+	restURL := controllerRestURL(tridentconfig.ServerCertName, port)
 	p.restClient, err = controllerAPI.CreateTLSRestClient(restURL, caCert, clientCert, clientKey)
 	if err != nil {
 		return nil, err

frontend/csi/plugin_test.go

@@ -37,6 +37,40 @@ import (
 	"github.com/netapp/trident/utils/osutils"
 )
 
+func TestControllerRestURL(t *testing.T) {
+	testCases := []struct {
+		name     string
+		host     string
+		port     string
+		expected string
+	}{
+		{
+			name:     "IPv6 address",
+			host:     "2001:db8::1",
+			port:     "34571",
+			expected: "https://[2001:db8::1]:34571",
+		},
+		{
+			name:     "IPv4 address",
+			host:     "192.0.2.10",
+			port:     "34571",
+			expected: "https://192.0.2.10:34571",
+		},
+		{
+			name:     "DNS name",
+			host:     "trident-csi",
+			port:     "34571",
+			expected: "https://trident-csi:34571",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			assert.Equal(t, tc.expected, controllerRestURL(tc.host, tc.port))
+		})
+	}
+}
+
 func TestNewControllerPlugin(t *testing.T) {
 	testCases := []struct {
 		name          string