kubeadm: alpha certs should skip missing files

cmd/kubeadm/app/cmd/alpha/certs.go

@@ -206,6 +206,11 @@ func renewCert(flags *renewFlags, kdir string, handler *renewal.CertificateRenew
 		return err
 	}
 
+	if ok, _ := rm.CertificateExists(handler.Name); !ok {
+		fmt.Printf("MISSING! %s\n", handler.LongName)
+		return nil
+	}
+
 	// if the renewal operation is set to generate CSR request only
 	if flags.csrOnly {
 		// checks a path for storing CSR request is given
@@ -282,36 +287,54 @@ func newCmdCertsExpiration(out io.Writer, kdir string) *cobra.Command {
 			w := tabwriter.NewWriter(out, 10, 4, 3, ' ', 0)
 			fmt.Fprintln(w, "CERTIFICATE\tEXPIRES\tRESIDUAL TIME\tCERTIFICATE AUTHORITY\tEXTERNALLY MANAGED")
 			for _, handler := range rm.Certificates() {
-				e, err := rm.GetCertificateExpirationInfo(handler.Name)
-				if err != nil {
-					return err
+				if ok, _ := rm.CertificateExists(handler.Name); ok {
+					e, err := rm.GetCertificateExpirationInfo(handler.Name)
+					if err != nil {
+						return err
+					}
+
+					s := fmt.Sprintf("%s\t%s\t%s\t%s\t%-8v",
+						e.Name,
+						e.ExpirationDate.Format("Jan 02, 2006 15:04 MST"),
+						duration.ShortHumanDuration(e.ResidualTime()),
+						handler.CAName,
+						yesNo(e.ExternallyManaged),
+					)
+
+					fmt.Fprintln(w, s)
+					continue
 				}
 
-				s := fmt.Sprintf("%s\t%s\t%s\t%s\t%-8v",
-					e.Name,
-					e.ExpirationDate.Format("Jan 02, 2006 15:04 MST"),
-					duration.ShortHumanDuration(e.ResidualTime()),
-					handler.CAName,
-					yesNo(e.ExternallyManaged),
+				// the certificate does not exist (for any reason)
+				s := fmt.Sprintf("!MISSING! %s\t\t\t\t",
+					handler.Name,
 				)
-
 				fmt.Fprintln(w, s)
 			}
 			fmt.Fprintln(w)
 			fmt.Fprintln(w, "CERTIFICATE AUTHORITY\tEXPIRES\tRESIDUAL TIME\tEXTERNALLY MANAGED")
 			for _, handler := range rm.CAs() {
-				e, err := rm.GetCAExpirationInfo(handler.Name)
-				if err != nil {
-					return err
+				if ok, _ := rm.CAExists(handler.Name); ok {
+					e, err := rm.GetCAExpirationInfo(handler.Name)
+					if err != nil {
+						return err
+					}
+
+					s := fmt.Sprintf("%s\t%s\t%s\t%-8v",
+						e.Name,
+						e.ExpirationDate.Format("Jan 02, 2006 15:04 MST"),
+						duration.ShortHumanDuration(e.ResidualTime()),
+						yesNo(e.ExternallyManaged),
+					)
+
+					fmt.Fprintln(w, s)
+					continue
 				}
 
-				s := fmt.Sprintf("%s\t%s\t%s\t%-8v",
-					e.Name,
-					e.ExpirationDate.Format("Jan 02, 2006 15:04 MST"),
-					duration.ShortHumanDuration(e.ResidualTime()),
-					yesNo(e.ExternallyManaged),
+				// the CA does not exist (for any reason)
+				s := fmt.Sprintf("!MISSING! %s\t\t\t",
+					handler.Name,
 				)
-
 				fmt.Fprintln(w, s)
 			}
 			w.Flush()

cmd/kubeadm/app/phases/certs/renewal/manager.go

@@ -315,6 +315,16 @@ func (rm *Manager) CreateRenewCSR(name, outdir string) error {
 	return nil
 }
 
+// CertificateExists returns true if a certificate exists.
+func (rm *Manager) CertificateExists(name string) (bool, error) {
+	handler, ok := rm.certificates[name]
+	if !ok {
+		return false, errors.Errorf("%s is not a known certificate", name)
+	}
+
+	return handler.readwriter.Exists(), nil
+}
+
 // GetCertificateExpirationInfo returns certificate expiration info.
 // For PKI certificates, use the name defined in the certsphase package, while for certificates
 // embedded in the kubeConfig files, use the kubeConfig file name defined in the kubeadm constants package.
@@ -341,6 +351,16 @@ func (rm *Manager) GetCertificateExpirationInfo(name string) (*ExpirationInfo, e
 	return newExpirationInfo(name, cert, externallyManaged), nil
 }
 
+// CAExists returns true if a certificate authority exists.
+func (rm *Manager) CAExists(name string) (bool, error) {
+	handler, ok := rm.cas[name]
+	if !ok {
+		return false, errors.Errorf("%s is not a known certificate", name)
+	}
+
+	return handler.readwriter.Exists(), nil
+}
+
 // GetCAExpirationInfo returns CA expiration info.
 func (rm *Manager) GetCAExpirationInfo(name string) (*ExpirationInfo, error) {
 	handler, ok := rm.cas[name]

cmd/kubeadm/app/phases/certs/renewal/readwriter.go

@@ -19,6 +19,7 @@ package renewal
 import (
 	"crypto"
 	"crypto/x509"
+	"os"
 	"path/filepath"
 
 	"github.com/pkg/errors"
@@ -33,6 +34,9 @@ import (
 // certificateReadWriter defines the behavior of a component that
 // read or write a certificate stored/embedded in a file
 type certificateReadWriter interface {
+	//Exists return true if the certificate exists
+	Exists() bool
+
 	// Read a certificate stored/embedded in a file
 	Read() (*x509.Certificate, error)
 
@@ -55,6 +59,20 @@ func newPKICertificateReadWriter(certificateDir string, baseName string) *pkiCer
 	}
 }
 
+// Exists checks if a certificate exist
+func (rw *pkiCertificateReadWriter) Exists() bool {
+	certificatePath, _ := pkiutil.PathsForCertAndKey(rw.certificateDir, rw.baseName)
+	return fileExists(certificatePath)
+}
+
+func fileExists(filename string) bool {
+	info, err := os.Stat(filename)
+	if os.IsNotExist(err) {
+		return false
+	}
+	return !info.IsDir()
+}
+
 // Read a certificate from a file the K8s pki managed by kubeadm
 func (rw *pkiCertificateReadWriter) Read() (*x509.Certificate, error) {
 	certificatePath, _ := pkiutil.PathsForCertAndKey(rw.certificateDir, rw.baseName)
@@ -97,6 +115,11 @@ func newKubeconfigReadWriter(kubernetesDir string, kubeConfigFileName string) *k
 	}
 }
 
+// Exists checks if a certificate embedded in kubeConfig file exists
+func (rw *kubeConfigReadWriter) Exists() bool {
+	return fileExists(rw.kubeConfigFilePath)
+}
+
 // Read a certificate embedded in kubeConfig file managed by kubeadm.
 // Please note that the kubeConfig file itself is kept in the ReadWriter state thus allowing
 // to preserve the attributes (Context, Servers, AuthInfo etc.)