Envoy proxy to use second corporate proxy for any host requested by client

[Dennis Vu]

I'm trying to allow clients make a request to a host destination, i.e. https://www.google.com through an envoy proxy. The envoy proxy would then use another proxy located at say http://corp.proxy.net. This would be for both http_proxy and https_proxy.  Expected behavior is all destination requests, both http and https, uses http://corp.proxy.net.

1. Client makes a request: curl --proxy http://envoy.proxy.net:1000 https://www.google.com
2. Envoy proxy uses another proxy at http://corp.proxy.net to send the request for https://www.google.com
3. Client receives the response from https://www.google.com

The issues I'm seeing is when the client makes a request to a host with https it'll connect to the other proxy with https, i.e. https://corp.proxy.net, instead of http://corp.proxy.net.

My configuration is similar to this

https://github.com/envoyproxy/envoy/blob/main/configs/proxy_connect.yaml

The end goal would look something like this.

Looking to do something like this
Client --http-> envoy proxy --http--> corp proxy

Client --https--> somehost.com