docs: def acme_renew_certificates():
      '''
          Renew certificates with acme_tiny for let's encrypt
      '''
  
      for csr in glob(os.path.join(CERTIFICATES_PATH, '*.csr')):
          common_name = os.path.basename(csr)
          common_name = os.path.splitext(common_name)[0]
  
          certificate_path = "{}.crt".format(common_name)
          certificate_path = os.path.join(CERTIFICATES_PATH, certificate_path)
  
          with open(certificate_path) as file:
              crt = OpenSSL.crypto.load_certificate(OpenSSL.crypto.FILETYPE_PEM,
                                                      file.read())
              expiration = crt.get_notAfter()
              expiration = _parse_asn1_generalized_date(expiration)
              remaining = expiration - datetime.utcnow()
              if remaining > timedelta(days=30):
                  print "No need to renew {} ({})".format(certificate_path, remaining)
                  continue
              print "Renewing {} ({})".format(certificate_path, remaining)
  
          certificate_request_path = "{}.csr".format(common_name)
          certificate_request_path = os.path.join(CERTIFICATES_PATH,
                                                  certificate_request_path)
  
          signed_cert = "{}-signed.crt".format(common_name)
          signed_cert = os.path.join(CERTIFICATES_PATH,
                                      signed_cert)
  
          _internal_sign_certificate(certificate_path, certificate_request_path,
                                      signed_cert)