From 6d6d200c3a7f611037db7a6200271da7e59983a0 Mon Sep 17 00:00:00 2001
From: Haleygo <hui.wang@daocloud.io>
Date: Fri, 25 Jun 2021 23:29:59 +0800
Subject: [PATCH] dry-run can work when using an external ca

---
 cmd/kubeadm/app/cmd/init.go                   |  3 ---
 cmd/kubeadm/app/cmd/phases/init/certs.go      | 16 ++++++++++++++++
 cmd/kubeadm/app/cmd/phases/init/kubeconfig.go | 15 +++++++++++++++
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/cmd/kubeadm/app/cmd/init.go b/cmd/kubeadm/app/cmd/init.go
index e09f5e2b1e1..ceb5e6a3262 100644
--- a/cmd/kubeadm/app/cmd/init.go
+++ b/cmd/kubeadm/app/cmd/init.go
@@ -386,9 +386,6 @@ func newInitData(cmd *cobra.Command, args []string, options *initOptions, out io
 		// Validate that also the required kubeconfig files exists and are invalid, because
 		// kubeadm can't regenerate them without the CA Key
 		kubeconfigDir := options.kubeconfigDir
-		if options.dryRun {
-			kubeconfigDir = dryRunDir
-		}
 		if err := kubeconfigphase.ValidateKubeconfigsForExternalCA(kubeconfigDir, cfg); err != nil {
 			return nil, err
 		}
diff --git a/cmd/kubeadm/app/cmd/phases/init/certs.go b/cmd/kubeadm/app/cmd/phases/init/certs.go
index e9890666367..bf48ebd41fd 100644
--- a/cmd/kubeadm/app/cmd/phases/init/certs.go
+++ b/cmd/kubeadm/app/cmd/phases/init/certs.go
@@ -18,6 +18,8 @@ package phases
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/pkg/errors"
@@ -197,6 +199,20 @@ func runCerts(c workflow.RunData) error {
 	}
 
 	fmt.Printf("[certs] Using certificateDir folder %q\n", data.CertificateWriteDir())
+
+	// If using an external CA while dryrun, copy CA cert to dryrun dir for later use
+	if data.ExternalCA() && data.DryRun() {
+		externalCAFile := filepath.Join(data.Cfg().CertificatesDir, kubeadmconstants.CACertName)
+		fileInfo, _ := os.Stat(externalCAFile)
+		contents, err := os.ReadFile(externalCAFile)
+		if err != nil {
+			return err
+		}
+		err = os.WriteFile(filepath.Join(data.CertificateWriteDir(), kubeadmconstants.CACertName), contents, fileInfo.Mode())
+		if err != nil {
+			return err
+		}
+	}
 	return nil
 }
 
diff --git a/cmd/kubeadm/app/cmd/phases/init/kubeconfig.go b/cmd/kubeadm/app/cmd/phases/init/kubeconfig.go
index f2f6b7d3cb4..3d1f304a084 100644
--- a/cmd/kubeadm/app/cmd/phases/init/kubeconfig.go
+++ b/cmd/kubeadm/app/cmd/phases/init/kubeconfig.go
@@ -18,6 +18,8 @@ package phases
 
 import (
 	"fmt"
+	"os"
+	"path/filepath"
 
 	"github.com/pkg/errors"
 	"k8s.io/kubernetes/cmd/kubeadm/app/cmd/options"
@@ -132,6 +134,19 @@ func runKubeConfigFile(kubeConfigFileName string) func(workflow.RunData) error {
 		// if external CA mode, skip certificate authority generation
 		if data.ExternalCA() {
 			fmt.Printf("[kubeconfig] External CA mode: Using user provided %s\n", kubeConfigFileName)
+			// If using an external CA while dryrun, copy kubeconfig files to dryrun dir for later use
+			if data.DryRun() {
+				externalCAFile := filepath.Join(kubeadmconstants.KubernetesDir, kubeConfigFileName)
+				fileInfo, _ := os.Stat(externalCAFile)
+				contents, err := os.ReadFile(externalCAFile)
+				if err != nil {
+					return err
+				}
+				err = os.WriteFile(filepath.Join(data.KubeConfigDir(), kubeConfigFileName), contents, fileInfo.Mode())
+				if err != nil {
+					return err
+				}
+			}
 			return nil
 		}