nginx ingress 报错 504 timeout，是由于反向代理超时造成的，反向代理默认超时时间60s
官方文档
配置片段：
apiVersion: extensions/v1beta1
kind: Ingress
metadata:
annotations:
nginx.ingress.kubernetes.io/proxy-connect-timeout: "300"
nginx.ingress.kubernetes.io/proxy-read-timeout: "300"
nginx.ingress.kubernetes.io/proxy-send-timeout: "300"