Add support for retries

[webberig]

We use express-http-proxy in an API gateway that proxies requests to microservices behind the firewall.

We've been having an issue where rare random requests are failing due to a DNS error getaddrinfo EAI_AGAIN. While this error is not related to express-http-proxy, someone suggested we would add a retry mechanism. PHP-HTTP, Guzzle, node-fetch, ... all seem to have solutions (with or without extra libraries), but I can't seem to find a solution for the proxy requests we do in our API gateway.

Would it be possible to implement a maxRetries option which will retry the upstream request in case of low-level errors, or maybe even 502/503 responses ?

[adams-family]

+1

I agree it would be fantastic to have auto-retry as this would greatly raise the value of this package as a high-availability proxy

[myl117]

+1

[poteat]

+1