response_headers_to_remove remove server header

[tydurd]

Hi team, I have the following envoy configuration (envoy v.1.12.2) and can't find a way to remove 'server' from response headers.

static_resources:
listeners:
- address:
socket_address:
address: 0.0.0.0
port_value: 80
filter_chains:
- filters:
- name: envoy.http_connection_manager
config:
server_name: "demo"
codec_type: auto
stat_prefix: ingress_http
route_config:
response_headers_to_remove:
- server
- x-envoy-upstream-service-time
name: local_route
virtual_hosts:
- name: bookservice
domains:
- "*"
routes:
- match:
prefix: "/"
route:
cluster: localcluster
http_filters:
- name: envoy.router
config: {}
clusters:
- name: localcluster
connect_timeout: 2.25s
type: static
lb_policy: round_robin
hosts:
- socket_address:
address: 127.0.0.1
port_value: 8080
admin:
access_log_path: "/dev/stdout"
address:
socket_address:
address: 0.0.0.0
port_value: 8081

I've tried removing the header both in the virtual host config and route config without success. What am I missing?

[alyssawilk]

response_headers_to_remove removes headers sent by upstream, but Envoy often adds its own server header.
There's an HCM field "server_header_transformation" - I suspect setting it to PASS_THROUGH may solve your problem.

https://www.envoyproxy.io/docs/envoy/latest/api-v3/extensions/filters/network/http_connection_manager/v3/http_connection_manager.proto.html?highlight=server_header_transformation#envoy-v3-api-enum-extensions-filters-network-http-connection-manager-v3-httpconnectionmanager-serverheadertransformation