[subnet]: 502 Bad Gateway

[yanmo96]

We have observed in k8s, when create a simple subnet will return a 502 Bad Gateway error. Steps to reproduce on swagger:

1. Create a VPC:

   {
   "network": {
       "admin_state_up": true,
       "revision_number": 0,
       "cidr": "",
       "default": true,
       "description": "vpc",
       "dns_domain": "domain",
       "id": "",
       "is_default": true,
       "mtu": 1400,
       "name": "YM_sample_vpc",
       "port_security_enabled": true,
       "project_id": "123456789"
   }
   }

2. Create the subnet:

   {
   "subnet": {
       "cidr": "10.0.1.0/24",
       "id": "",
       "name": "YM_sample_subnet",
       "ip_version": 4,
       "network_id": "48a5de9f-d8ed-4a78-8a20-83c6c099fd08"
   }
   }

The response from subnet create will be the following:

{
  "timestamp": "2022-08-16T22:20:56.601+0000",
  "status": 500,
  "error": "Internal Server Error",
  "message": "500 : [{\"timestamp\":\"2022-08-16T22:20:56.588+0000\",\"status\":500,\"error\":\"Internal Server Error\",\"message\":\"502 Bad Gateway: [no body]\",\"path\":\"/project/123456789/subnets/48ec6986-de0c-49c5-99e9-80f19aa734c4/routetable\"}]",
  "path": "/project/123456789/subnets"
}