unable to proxy + rewrite in a single route

[RangerRick]

I would like to attach a sub-url to my unit config so that a particular URL proxies, but also rewrites the path passed to the proxy by stripping the sub-url.

For example, a request to /s3/mybucket/blah/foo would proxy to http://1.2.3.4:8333/mybucket/blah/foo, stripping the /s3 from the beginning the path.

I've attempted a bunch of different variations and I can't seem to find a way to make it work, although the documentation says "All route step actions support the rewrite option". Is this just not supported, or am I just doing something wrong?

Here's the config:

{
  "listeners": {
    "0.0.0.0:8080": {
      "pass": "routes/main"
    }
  },
  "routes": {
    "main": [
      {
        "match": {
          "uri": "/static/*"
        },
        "action": {
          "share": "/opt/myapp${uri}"
        }
      },
      {
        "match": {
          "uri": "~^/?s3/(.*)$"
        },
        "action": {
          "rewrite": "/$1",
          "proxy": "http://<ip-addr>:8333/"
        }
      },
      {
        "action": {
          "pass": "applications/myapp"
        }
      }
    ]
  },
  "applications": {
    "myapp": {
      "type": "python 3",
      "path": "/opt/myapp/",
      "module": "myapp.wsgi",
      "home": "/opt/myapp/venv",
      "processes": {
        "max": 4,
        "spare": 1,
        "idle_timeout": 120
      }
    }
  },
  "access_log": "/dev/stdout"
}

[hongzhidao]

Hi,
Currently, it's not supported yet. But we've discussed it and will release it in 1.34 as the next version.
https://github.com/nginx/unit/issues/544
Btw, it will be different from nginx's way. Nginx provides a number-format variable, but we think it's better to support only captured name variables in Unit.