fix: invoke failedToRenewCert in case of failure to renew cert on simplecert.Init and keep runnning

Author: dreadl0ck

simplecert.go

@@ -147,7 +147,17 @@ func Init(cfg *Config, cleanup func()) (*CertReloader, error) {
 // renew cert if necessary
 errRenew := renew(cert)
 if errRenew != nil {
-return nil, errors.New("simplecert: failed to renew cached cert on startup: " + errRenew.Error())
+
+// call handler if set
+if c.FailedToRenewCertificate != nil {
+
+// invoke the user's handler
+c.FailedToRenewCertificate(errRenew)
+
+// if a handler was called keep running and init normally
+} else {
+return nil, errors.New("simplecert: failed to renew cached cert on startup and no failedToRenewCert handler is configured: " + errRenew.Error())
+}
 }
 
 // kickoff renewal routine