host header not set correctly in automatic endpoint discovery for aws connector

[doodlesbykumbi]

Summary

A clear and concise description of what the bug is.

Steps to Reproduce

Steps to reproduce the behavior:

1. Setup a Secretless service with an AWS connector at 8080, with automatic endpoint discovery (--endpoint-url http://secretless.empty in the alias below) .

alias aws="AWS_ACCESS_KEY_ID=x AWS_SECRET_ACCESS_KEY=x HTTP_PROXY=http://localhost:8080 aws --endpoint-url http://secretless.empty"

2. Run aws s3 ls to list all buckets. You'll likely get

An error occurred (NoSuchBucket) when calling the ListObjectsV2 operation: The specified bucket does not exist

NOTE: This bug doesn't show up for aws sts get-caller-identity, maybe this endpoint doesn't care about the Host header.

This bug does not show up when you manually set the endpoint. So aws --endpoint-url http://s3.us-east-1.amazonaws.com s3 ls works perfectly fine.

Expected Results

It should just work. The AWS-CLI should return the list of buckets on the AWS account in question.

Actual Results (including error logs, if applicable)

1. We get an error from AWS-CLI.

   An error occurred (NoSuchBucket) when calling the ListObjectsV2 operation: The specified bucket does not exist
   

2. Upon inspection of debug logs from Secretless we see that the host header for the request to the AWS endpoint is not the right value

   2021/01/26 23:29:00 [DEBUG] HTTP Proxy on tcp://0.0.0.0:8080: Making request: 
   GET /?delimiter=%2F&encoding-type=url&list-type=2&prefix= HTTP/1.1
   Host: secretless.empty
   Accept-Encoding: identity
   

Additional Information

N/A