Ignore permission errors on config-dir (#6894)

cmd/certs.go

@@ -71,9 +71,13 @@ func getRootCAs(certsCAsDir string) (*x509.CertPool, error) {
 	// Get all CA file names.
 	var caFiles []string
 	fis, err := readDir(certsCAsDir)
-	if err != nil {
+	if err != nil && err != errFileNotFound {
 		return nil, err
 	}
+	// Return success if CA's directory is missing.
+	if err == errFileNotFound {
+		return nil, nil
+	}
 	for _, fi := range fis {
 		// Skip all directories.
 		if hasSuffix(fi, slashSeparator) {

cmd/certs_test.go

@@ -223,7 +223,8 @@ func TestGetRootCAs(t *testing.T) {
 		certCAsDir  string
 		expectedErr error
 	}{
-		{"nonexistent-dir", errFileNotFound},
+		// ignores non-existent directories.
+		{"nonexistent-dir", nil},
 		// Ignores directories.
 		{dir1, nil},
 		// Ignore empty directory.

cmd/config-dir.go

@@ -74,7 +74,15 @@ func (config *ConfigDir) GetCADir() string {
 
 // Create - creates configuration directory tree.
 func (config *ConfigDir) Create() error {
-	return os.MkdirAll(config.GetCADir(), 0700)
+	err := os.MkdirAll(config.GetCADir(), 0700)
+	// It is possible in kubernetes like deployments this directory
+	// is already mounted and is not writable, ignore any write errors.
+	if err != nil {
+		if os.IsPermission(err) {
+			err = nil
+		}
+	}
+	return err
 }
 
 // GetMinioConfigFile - returns absolute path of config.json file.