Merge pull request #531 from joscha-alisch/dont-allow-same-port-twice

Try to open port before allowing it

internal/view/container.go

@@ -3,6 +3,7 @@ package view
 import (
 	"errors"
 	"fmt"
+	"net"
 	"strings"
 
 	"github.com/derailed/k9s/internal/client"
@@ -140,3 +141,11 @@ func (c *Container) isForwardable(path string) ([]string, bool) {
 
 	return pp, true
 }
+
+func tryListenPort(port string) error {
+	server, err := net.Listen("tcp", fmt.Sprintf(":%s", port))
+	if err != nil {
+		return err
+	}
+	return server.Close()
+}