transport: loopyWriter.run returning. connection error: desc = "transport is closing"

[bcba25]

I got an issue with gRPC service. I'm using grpc-web on my client side Angular application.

I constantly receiving CORS error:

has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled.

and also sometimes I do receive the following message on the grpc server:

transport: loopyWriter.run returning. connection error: desc = "transport is closing"

and the logging shows that grpc request received but no response sent back to the client app

Here are my configs:

Consul LDS:

[{
	"name": "listener_0",
	"address": {
		"socket_address": {
			"address": "0.0.0.0",
			"port_value": 8080
		}
	},
	"filter_chains": [{
		"filters": [{
			"name": "envoy.http_connection_manager",
			"config": {
				"codec_type": "auto",
				"stat_prefix": "ingress_http",
				"route_config": {
					"name": "local_route",
					"virtual_hosts": [{
						"name": "local_service",
						"domains": [
							"*"
						],
						"routes": [{
							"match": {
								"prefix": "/App.Grpc.MyApp1"
							},
							"route": {
								"cluster": "main_service",
								"max_grpc_timeout": "0s"
							}
						}],
            "cors": {
              "allow_origin": [
                "*"
              ],
              "allow_methods": "GET, PUT, DELETE, POST, OPTIONS",
              "allow_headers": "keep-alive, user-agent, cache-control, content-type, content-transfer-encoding, Authorization, x-ip, x-accept-content-transfer-encoding, x-accept-response-streaming, x-user-agent, x-grpc-web, grpc-timeout",
              "max_age": "1728000",
              "expose_headers": "grpc-status, grpc-message",
              "enable": true
            }
					}]
				},
				"http_filters": [{
						"name": "envoy.cors"
					},
					{
						"name": "envoy.grpc_web"
					},
					{
						"name": "envoy.router"
					}
				]
			}
		}]
	}]
}]

Consul CDS:

[{
	"name": "MyApp1",
	"connect_timeout": "0.25s",
	"type": "logical_dns",
	"lb_policy": "round_robin",
	"http2_protocol_options": {},
	"hosts": [{
		"socket_address": {
			"address": "host.docker.internal", # also tried docker service name my_app
			"port_value": 50053
		}
	}]
}]

When I'm running envoy and go service without Pilot, everything works fine with exactly same configs, trying to figure out how to update envoy dynamically. Any help would be appreciated!