Custom upstrem/backend response #12883
Description
I want to rewrite the 4xx/5xx returned by the upstrem/backend service.
I see that envoy 1.15.0 has been able to rewrite the error of envoy itself through local_reply_config, but it seems that it cannot rewrite the error returned by upstrem/backend. The function of local_reply_config is very good and can replace haproxy as the front end lb. It would be even better if could rewrite upstrem/backend.
I don’t know if my configuration is wrong, my configuration：
apiVersion: networking.istio.io/v1alpha3
kind: EnvoyFilter
metadata:
name: local-reply
namespace: istio-system
spec:
configPatches:
- applyTo: NETWORK_FILTER # http connection manager is a filter in Envoy
match:
context: GATEWAY
listener:
filterChain:
filter:
name: "envoy.http_connection_manager"
patch:
operation: MERGE
value:
typed_config:
"@type": "type.googleapis.com/envoy.extensions.filters.network.http_connection_manager.v3.HttpConnectionManager"
local_reply_config:
mappers:
- filter:
status_code_filter:
comparison:
op: EQ
value:
default_value: 503
runtime_key: key_b
status_code: 200
body:
inline_string: "no health server"
body_format_override:
json_format:
status: "503"
message: "%LOCAL_REPLY_BODY%"
request_path: "%REQ(:path)%"[root@k8s-20 ~]# curl -i http://test.domain.com/503/test/path
HTTP/1.1 503 Service Unavailable
server: nginx/1.15.6
date: Sat, 29 Aug 2020 03:51:36 GMT
content-type: text/html
content-length: 203
x-request-id: 3c4a04cd-c4d3-4819-af76-256b6c905a0b
<html>
<head><title>503 Service Temporarily Unavailable</title></head>
<body>
<center><h1>503 Service Temporarily Unavailable</h1></center>
<hr><center>openresty/1.15.8.2</center>
</body>
</html>