title: HTTP relay / proxy / mapping server
body: <p>I'm trying to set up a simple relay / mapping server locally and feel there has to be some off the shelf solution, but I can't seem to find it.</p>
  
  <p>I'm debugging an application of mine that needs to connect to host_A.  Instead of connecting to host_A I want to configure it to connect to <strong>local_proxy</strong>.  I don't want to use proxying protocols, but instead want to configure it to connect to <code>http://localhost:80</code> and then have <strong>local_proxy</strong> connect to <code>host_A</code> and have <strong>local_proxy</strong> simply relay all messages back and forth.</p>
  
  <p>I would expect to have to configure <strong>local_proxy</strong> to tell it what server it is supposed to relaying</p>
  
  <p>Then there is 1 particular endpoint I want to be able to intercept and change the return info so I can better debug my application.</p>
  
  <p>I thought I should be able to do this with <a href="https://www.charlesproxy.com/" rel="nofollow noreferrer">Charles Proxy</a>, but I couldn't figure out how.</p>
  
  <p>At the moment, this doesn't need to support SSL (though that would always be nice).</p>