the proxy replay mode is not working

[funkyfuture]

Describe the bug

a pywb instance that is configured to run in 'proxy-mode' for replay, not recording, shows 'Pywb Error No handler for <path>' instead of the expected archived web page.

the search page of the collection is returned as in the usual unproxied mode regardless which hostname is used in the browser.

Steps to reproduce the bug

0a. there's an archive containing the archive contents of http://sub.domain.tld/foo in a collection named default. 0b. a webserver / proxy is configured to pass any incoming request to the socket pywb will listen to.

1. launch pywb instances as wsgi workers w/ the following config.yml contents:

---

debug: true

proxy:
  coll: default

framed_replay: false 

2. the workers log INFO:pywb.apps.frontendapp:Proxy enabled for collection "default".
3. request http://sub.domain.tld/foo in a browser, the afore mentioned content is displayed.
4. request http://sub.domain.tld/default or http://any.other.name/default, the page to search the default collection is displayed. (the archived contents can be found and accessed via the /<collection>/<timestamp>/<url> scheme from here.)

Expected behavior

at step 3. i'd expect to get the archived page w/ a header as response. at step 4. i'd expect to get a 'Url Not Found' page as response.

Environment (server)

• OS: Ubuntu 18.04
• pywb: 2.1.0

[funkyfuture]

the same is true for an instance that is invoked w/ pywb --proxy default.

[sydoluciani]

@funkyfuture It works as expected on Debian 10 (bullseye/sid) and pywb version 2.4.2, however default config file name is config.yaml and not config.yml.