How to deploy grpc-web on aws? - amazon-web-services

Question

I have a backend service that I want to expose via grpc-web.
I'm able to use the service directly via the public IP of the ec2 instance. But when I try to access it via the invocation URL of API Gateway I get a CORS error.
I want to add JWT authentication that's why I want to expose the API via API-Gateway.
Here is my configuration:
Envoy.yml
admin:
access_log_path: /tmp/admin_access.log
address:
socket_address: { address: 0.0.0.0, port_value: 9901 }
static_resources:
listeners:
- name: listener_sim
address:
socket_address: { address: 0.0.0.0, port_value: 8080 }
filter_chains:
- filters:
- name: envoy.filters.network.http_connection_manager
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager
codec_type: auto
stat_prefix: ingress_http
route_config:
name: local_route
virtual_hosts:
- name: local_service
domains: ["*"]
routes:
- match: { prefix: "/" }
route:
cluster: rtdxc_service
timeout: 0s
max_stream_duration:
grpc_timeout_header_max: 0s
cors:
allow_origin_string_match:
- prefix: "*"
allow_methods: GET, PUT, DELETE, POST, OPTIONS
allow_headers: keep-alive,user-agent,cache-control,content-type,content-transfer-encoding,custom-header-1,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
http_filters:
- name: envoy.filters.http.grpc_web
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.grpc_web.v3.GrpcWeb
- name: envoy.filters.http.cors
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.cors.v3.Cors
- name: envoy.filters.http.router
typed_config:
"#type": type.googleapis.com/envoy.extensions.filters.http.router.v3.Router
clusters:
- name: grpc_server
connect_timeout: 0.25s
type: logical_dns
http2_protocol_options: {}
lb_policy: round_robin
load_assignment:
cluster_name: rtdxc_0
endpoints:
- lb_endpoints:
- endpoint:
address:
socket_address:
address: grpc_server
port_value: 8081
Here is my docker-compose.yml
version: '3.8'
services:
grpc_server:
image: XXXXXX
user: ${UID}:${GID}
ports:
- 8081:8081
tty: true
proxy:
ports:
- 9091:9091
- 8080:8080
image: envoyproxy/envoy:v1.22.0
volumes:
- ./envoy/envoy.yml:/etc/envoy/envoy.yaml:ro
tty:
true
I have mapped API gateway with the following configuration:
ANY / mappes to the public domain of the ec2 instance on port 8080
If I add CORS configuration in the API Gateway , The OPTION request returns 204 with propper cors headers, but POST request does not return proper headers. If I disable CORS configuration in the API gateway, the OPTIONS request also fails due to CORS issue.