Krakend Shadowproxy Middleware

This package contains custom middleware to add a shadow backend to a KrakenD proxy pipe. It can be used to mirror proxy requests to a secondary backend, similar to KrakenD's inbuilt shadow functionality (which does not support proxy requests).

Installation

To install shadowproxy from GitHub:

go get -u github.com/kivra/krakend-shadowproxy@<commit hash>

Quick Start

Using the following configuration, an incoming request to KrakenD's /v1/user/123 endpoint is proxied to https://my.backend.com/v2/user/123, together with a shadow request to https://other.backend.com/v3/user/123. The return value of the shadow request is ignored.

"endpoints": [
  {
    "endpoint": "/v1/user/{ukey}",
    "method": "POST",
    "output_encoding": "no-op",
    "extra_config": {
      "kivra/shadowproxy": {
        "host": [ "https://other.backend.com" ],
        "url_pattern": "/v3/user/{ukey}",
        "method": "POST"
      }
    },
    "backend": [
      {
        "host": [ "https://my.backend.com" ],
        "url_pattern": "/v2/user/{ukey}",
        "method": "POST",
        "encoding": "no-op"
      }
    ]
  }
]

Configuration Options

The middleware configuration supports the following parameters.

---

host

The host URL(s) of the backend(s) that will receive the shadow request.

---

url_pattern

The URL pattern used for requests to the shadow backend.

---

method (optional)

The request method used for requests to the shadow backend (default "GET").

---

disable_host_sanitize (optional)

Disable host sanitization for prodived host list (default false).

---

timeout (optional)

The timeout for the request to the shadow backend as a Go duration, for example 10s. Defaults to the endpoint timeout.