HTTP Proxy: Access to backends through a proxy

Document updated on May 12, 2023

The HTTP proxy adds an intermediate layer where the connection to the backend goes through an external proxy.

There are two different ways to connect to your backends through a corporate proxy:

• Connect to all backends using a proxy
• Connect to a specific backend using a proxy

Connecting to all backends using a proxy

Passing an environment variable HTTP_PROXY when starting the gateway ensures that all backend requests pass through the defined proxy. For instance:

$docker run --rm -v "$PWD:/etc/krakend" -e HTTP_PROXY=http://myproxy:8080 krakend/krakend-ee

Connecting to a specific backend using a proxy

If instead, you want to route a single backend connection through a proxy, you must add in the backend the proxy_address attribute under the backend/http/client namespace:

{
    "version": 3,
    "endpoints": [
        {
            "endpoint": "/health",
            "output_encoding": "no-op",
            "backend": [
                {
                    "url_pattern": "/__health",
                    "host": ["http://localhost:8080"],
                    "encoding": "no-op",
                    "extra_config": {
                        "backend/http/client": {
                            "proxy_address": "http://myproxy:8080"
                        }
                    }
                }
            ]
        }
    ]
}

The configuration flags relative to the proxy functionality is:

• proxy_address (string): The proxy address used to forward the traffic. The address must contain the protocol and the port.

The backend/http/client offers more options.

Migration from old plugin

Prior to v2.3 the http-proxy plugin offered this functionality, and is now deprecated as it is supported natively with the configuration explained above. If you used the plugin you will need to execute the following change in your configuration files:

"extra_config": {
-   "plugin/http-client": {
-       "name": "http-proxy",
-       "proxy_address": "http://myproxy:8080"
+   "backend/http/client": {
+       "proxy_address": "http://myproxy:8080"
    }