Gateway Proxy

Overview

The Gateway Proxy is a standalone application to be deployed separately. The proxy enables communication to an outbound server through it's REST API. If a request is send to it’s endpoint it will forward the request to upstream servers.

The proxy is build on top of Spring Boot. It's connection routing aware and offers authentication via OAuth20, Oauth10A, a Bearer Token forward mechanism and fixed headers.

Configuration

The proxy can be configured using environment variables and a configuration files. The configuration file for setting connection routing properties is called connection-routing.yml and has to be in the same directory as the gateway proxy jar package.

Allowing requests to all target servers

By default the proxy only works for outbound connections to URLs configured in the connection-routing-yml file. All other requests are blocked. Setting the environment variable PROXY_ALLOW_UNKNOWN_TARGETs to true allows requests to be proxied to all target URLs.

Logging verbosity

Logging verbosity can be controlled by an environment variable called PROXY_GATEWAY_LOG_LEVEL. Set this to DEBUG for full verbosity and to INFO for more concise logging output.

Running the Java application

After building the Gateway Proxy it can be started using the jar file built in the previous step:

#> java -jar target/smartfacts-gateway-proxy-<version>.jar

Running the Docker Container

The application is also provided as a docker container at registry.mid.de/smartfacts/smartfacts-gateway-proxy:latest and can be started using the docker-compose.yml file in the root directory of this project. The docker compose file is configured to run the application on port 8418 on the host machine. In order to supply a custom connection-routing.yml configuration file they can be mounted s volumes in the root directory of the docker image.

Proxy HTTP endpoint

The proxy application exposes the endpoint /proxy/stream to relay HTTP GET, POST, PUT, DELETE, PATCH and HEAD requests. Only requests to outbound servers that are configured in the connection-routing.yml configuration file are allowed by default. This behavior can be controlled by the environment variable PROXY_ALLOW_UNKNOWN_TARGETS.

Usage

Request sent to the endpoint /proxy/stream with a Request Parameter named target are proxied. The target request parameter has to be set to an outbound
server URL. The outbound server URL has to be url encoded. Responses from the outbound server are streamed through the proxy back to the user-agent.

Examples

1. Proxy a GET request to http://example.com/foo:

   #> curl -X GET http://proxy.host/proxy/stream?target=http%3a%2f%2fexample.com/foo

2. Proxy a Post request with a JSON body to http://example.com/bar:

    #> curl -X POST -H "Content-Type: appliction/json" -d '{"my-data": "baz"}' http://proxy.host/proxy/stream?target=http%3a%2f%2fexample.com/bar

Reference

Environment variables

Connection Routing

Please refer to the connection routing documentation.

Links:

• Connection Routing

• Spring Boot