Consolidate CopyFile functions (#8079)

pkg/agent/flannel/setup.go

@@ -157,7 +157,7 @@ func createCNIConf(dir string, nodeConfig *config.Node) error {
 
 	if nodeConfig.AgentConfig.FlannelCniConfFile != "" {
 		logrus.Debugf("Using %s as the flannel CNI conf", nodeConfig.AgentConfig.FlannelCniConfFile)
-		return util.CopyFile(nodeConfig.AgentConfig.FlannelCniConfFile, p)
+		return util.CopyFile(nodeConfig.AgentConfig.FlannelCniConfFile, p, false)
 	}
 	return util.WriteFile(p, cniConf)
 }

pkg/agent/util/file.go

@@ -16,10 +16,12 @@ func WriteFile(name string, content string) error {
 	return nil
 }
 
-func CopyFile(sourceFile string, destinationFile string) error {
+func CopyFile(sourceFile string, destinationFile string, ignoreNotExist bool) error {
 	os.MkdirAll(filepath.Dir(destinationFile), 0755)
 	input, err := os.ReadFile(sourceFile)
-	if err != nil {
+	if errors.Is(err, os.ErrNotExist) && ignoreNotExist {
+		return nil
+	} else if err != nil {
 		return errors.Wrapf(err, "copying %s to %s", sourceFile, destinationFile)
 	}
 	err = os.WriteFile(destinationFile, input, 0644)

pkg/cli/cert/cert.go

@@ -9,6 +9,7 @@ import (
 	"time"
 
 	"github.com/erikdubbelboer/gspt"
+	"github.com/k3s-io/k3s/pkg/agent/util"
 	"github.com/k3s-io/k3s/pkg/bootstrap"
 	"github.com/k3s-io/k3s/pkg/cli/cmds"
 	"github.com/k3s-io/k3s/pkg/clientaccess"
@@ -210,20 +211,6 @@ func rotate(app *cli.Context, cfg *cmds.Server) error {
 	return nil
 }
 
-func copyFile(src, destDir string) error {
-	_, err := os.Stat(src)
-	if err == nil {
-		input, err := os.ReadFile(src)
-		if err != nil {
-			return err
-		}
-		return os.WriteFile(filepath.Join(destDir, filepath.Base(src)), input, 0644)
-	} else if errors.Is(err, os.ErrNotExist) {
-		return nil
-	}
-	return err
-}
-
 func backupCertificates(serverDataDir, agentDataDir string) (string, error) {
 	serverTLSDir := filepath.Join(serverDataDir, "tls")
 	tlsBackupDir := filepath.Join(serverDataDir, "tls-"+strconv.Itoa(int(time.Now().Unix())))
@@ -234,18 +221,20 @@ func backupCertificates(serverDataDir, agentDataDir string) (string, error) {
 	if err := copy.Copy(serverTLSDir, tlsBackupDir); err != nil {
 		return "", err
 	}
-	agentCerts := []string{
-		filepath.Join(agentDataDir, "client-"+version.Program+"-controller.crt"),
-		filepath.Join(agentDataDir, "client-"+version.Program+"-controller.key"),
-		filepath.Join(agentDataDir, "client-kubelet.crt"),
-		filepath.Join(agentDataDir, "client-kubelet.key"),
-		filepath.Join(agentDataDir, "serving-kubelet.crt"),
-		filepath.Join(agentDataDir, "serving-kubelet.key"),
-		filepath.Join(agentDataDir, "client-kube-proxy.crt"),
-		filepath.Join(agentDataDir, "client-kube-proxy.key"),
+	certs := []string{
+		"client-" + version.Program + "-controller.crt",
+		"client-" + version.Program + "-controller.key",
+		"client-kubelet.crt",
+		"client-kubelet.key",
+		"serving-kubelet.crt",
+		"serving-kubelet.key",
+		"client-kube-proxy.crt",
+		"client-kube-proxy.key",
 	}
-	for _, cert := range agentCerts {
-		if err := copyFile(cert, tlsBackupDir); err != nil {
+	for _, cert := range certs {
+		agentCert := filepath.Join(agentDataDir, cert)
+		tlsBackupCert := filepath.Join(tlsBackupDir, cert)
+		if err := util.CopyFile(agentCert, tlsBackupCert, true); err != nil {
 			return "", err
 		}
 	}