Display SSL expiry warnings (#2925)

cmd/server-startup-msg.go

@@ -17,10 +17,12 @@
 package cmd
 
 import (
+	"crypto/x509"
 	"fmt"
 	"os"
 	"runtime"
 	"strings"
+	"time"
 
 	humanize "github.com/dustin/go-humanize"
 	"github.com/minio/mc/pkg/console"
@@ -46,10 +48,15 @@ func printStartupMessage(endPoints []string) {
 	printServerCommonMsg(endPoints)
 	printCLIAccessMsg(endPoints[0])
 	printObjectAPIMsg()
+
 	objAPI := newObjectLayerFn()
 	if objAPI != nil {
 		printStorageInfo(objAPI.StorageInfo())
 	}
+
+	if certs, err := readCertificateChain(); err == nil {
+		printCertificateMsg(certs)
+	}
 }
 
 // Prints common server startup message. Prints credential, region and browser access.
@@ -147,3 +154,28 @@ func printStorageInfo(storageInfo StorageInfo) {
 	console.Println()
 	console.Println(getStorageInfoMsg(storageInfo))
 }
+
+// Prints certificate expiry date warning
+func getCertificateChainMsg(certs []*x509.Certificate) string {
+	msg := colorBlue("\nCertificate expiry info:\n")
+	totalCerts := len(certs)
+	var expiringCerts int
+
+	for i := totalCerts - 1; i >= 0; i-- {
+		cert := certs[i]
+
+		if cert.NotAfter.Before(time.Now().Add(time.Hour * 24 * globalMinioCertExpireWarnDays)) {
+			expiringCerts++
+			msg += fmt.Sprintf(colorBold("#%d %s will expire on %s\n"), expiringCerts, cert.Subject.CommonName, cert.NotAfter)
+		}
+	}
+
+	if expiringCerts > 0 {
+		return msg
+	}
+	return ""
+}
+
+func printCertificateMsg(certs []*x509.Certificate) {
+	console.Println(getCertificateChainMsg(certs))
+}