example: # matching `app.y.z`
  # optional, defaults to http
  scheme:
  # required, proxy target
  host: 10.0.0.1
  # optional, defaults to 80 for http, 443 for https
  port: 80
  # optional, defaults to empty
  path:
  # optional, defaults to sub
  path_mode:
  # optional (https only)
  # no_tls_verify: false
app1: # matching `app1.y.z` -> http://x.y.z
  host: x.y.z
app2: # `app2` has no effect for tcp / udp, but still has to be unique across files
  scheme: tcp
  host: 10.0.0.2
  port: 20000:tcp
app3: # matching `app3.y.z` -> https://10.0.0.1/app3
  scheme: https
  host: 10.0.0.1
  path: /app3
  path_mode: forward
  no_tls_verify: false