Kubernetes Ingress 사용시 Upstream 에러 ( An invalid response was received from the upstream server )

 

버전 정보

K8S Version : 1.28

Ingress : Kong

Kong Log

upstream sent too big header while reading response header from upstream, client

문제 정의

Upstream 시 header size 가 작아서 에러가 나는 현상

해결 방안

/usr/local/kong/nginx-kong.conf 파일에 buffer size 를 늘려줌으로 해결

방안1 : /usr/local/kong/nginx-kong.conf 을 mount 하여 진행

nginx-kong.conf 을 만들어 진행

------------------------------------------------

...

fastcgi_buffers 4 32k;

fastcgi_buffer_size 28k;

fastcgi_busy_buffers_size 32k;

...

server {

...

proxy_buffer_size 28k; proxy_buffers 4 32k; proxy_busy_buffers_size 32k;

}

...

-----------------------------------------------

방안2 : Deployment 에 spec.env 값을 주어 진행

• - name: KONG_NGINX_PROXY_PROXY_BUFFER_SIZE
  value: "28k"
  - name: KONG_NGINX_PROXY_PROXY_BUSY_BUFFERS_SIZE
  value: "32k"
  - name: KONG_NGINX_PROXY_PROXY_BUFFERS
  value: "4 32k"
  - name: KONG_NGINX_HTTP_CLIENT_HEADER_BUFFER_SIZE
  value: "28k"
  - name: KONG_NGINX_HTTP_FASTCGI_BUFFER_SIZE
  value: "32k"
  - name: KONG_NGINX_HTTP_FASTCGI_BUSY_BUFFERS_SIZE
  value: "32k"
  - name: KONG_NGINX_HTTP_FASTCGI_BUFFERS
  value: "4 32k"

참조

https://nginx.org/en/docs/http/ngx_http_proxy_module.html#proxy_buffer_size

https://dev.jaedong.kim/nginx-upstream-sent-too-big-header-while-reading-response-header-from-upstream-error/

https://doogle.link/nginx-proxy-502-bad-gateway-%EC%98%A4%EB%A5%98-%ED%95%B4%EA%B2%B0%ED%95%98%EA%B8%B0-bad-upstream-sent-too-big-header-while-reading-response-header-from-upstream/