Cyberghost support (#168)

* Host finder CLI for cyberghost
* Resolver program updated with Cyberghost data
* Gluetun cli clientkey subcommand

internal/cli/cli.go

@@ -1,10 +1,34 @@
 package cli
 
 import (
+	"flag"
 	"fmt"
+	"strings"
+
 	"net"
+
+	"github.com/qdm12/golibs/files"
 )
 
+func ClientKey(args []string) error {
+	flagSet := flag.NewFlagSet("clientkey", flag.ExitOnError)
+	filepath := flagSet.String("path", "/client.key", "file path to the client.key file")
+	if err := flagSet.Parse(args); err != nil {
+		return err
+	}
+	fileManager := files.NewFileManager()
+	data, err := fileManager.ReadFile(*filepath)
+	if err != nil {
+		return err
+	}
+	s := string(data)
+	s = strings.ReplaceAll(s, "\n", "")
+	s = strings.TrimPrefix(s, "-----BEGIN PRIVATE KEY-----")
+	s = strings.TrimSuffix(s, "-----END PRIVATE KEY-----")
+	fmt.Println(s)
+	return nil
+}
+
 func HealthCheck() error {
 	ips, err := net.LookupIP("github.com")
 	if err != nil {