Ambassador-05-自动重试

自动重试定义：

retry_policy:
  retry_on: <string>
  num_retries: <integer>
  per_try_timeout: <string>

retry_on：必输项，可填如下：5xx, gateway-error, connect-failure, retriable-4xx, refused-stream, retriable-status-codes

num_retries：失败的重试次数

per_try_timeout：重试超时时间

---
apiVersion: getambassador.io/v2
kind:  Mapping
metadata:
  name:  quote-backend
spec:
  prefix: /backend/
  service: quote
  retry_policy:
    retry_on: "5xx"
    num_retries: 10