Reverse Proxy App

A lightweight, re-usable & configurable proxy app compatible with Skpr config.

What problem are we solving?

Skpr otherwise has no way to proxy one end-point to another using Skpr config.

Usage

The proxy does not need to be configured, but you can map a couple of configurable values to the Skpr configuration or using environment variables.

The environment variable will instruct the proxy which Skpr config key/value pair to use, for example PROXY_APP_ENDPOINT could be set to elasticsearch.default.endpoint.

	Environment Variable	Environment Variable (Skpr Config Use)	Explaination
Username	PROXY_APP_USERNAME	PROXY_APP_CONFIG_KEY_USERNAME	HTTP Basic Authentication username for target endpoint.
Password	PROXY_APP_PASSWORD	PROXY_APP_CONFIG_KEY_PASSWORD	HTTP Basic Authentication password for target endpoint.
Endpoint	PROXY_APP_ENDPOINT	PROXY_APP_CONFIG_KEY_ENDPOINT	The single endpoint you wish to proxy to which includes the schema and port. Example: https://54.206.202.192:4040
Address	PROXY_APP_ADDR	PROXY_APP_CONFIG_KEY_ADDR	The local address you wish to access the endpoint from, expressed as a port with an appended colon. Example: :8080

How to

Using GoReleaser

The release process is automated via goreleaser, and you can run it using the following:

$ goreleaser --snapshot --skip-publish --rm-dist

Build from source

The command should be run from a project compatible with Skpr, so that your Skpr configuration can get loaded in at runtime - elsewise it will depend on environment variables.

$ go build -o ${DESINATION_DIRECTORY}/proxy-app . && \
  chmod +x ./proxy-app && \
  cd ${DESINATION_DIRECTORY} && \
  ./proxy-app

Build using Docker

You can build the dockerfile using the following, as well as using the build arguments ass listed above. This example maps to port 7000 - the default is 8080. The application will serve on port 7000 of the container, and the run command maps port 7000 on the host to port 7000 on the container.

$ docker build --build-arg PROXY_APP_ADDR=:7000 --build-arg PROXY_APP_ENDPOINT=https://www.skpr.com.au -t skpr/proxy-app .
$ docker run -p 7000:7000 skpr/proxy-app
# Or...
$ docker run --rm -p 7000:7000 -e PROXY_APP_ADDR=:7000 -e PROXY_APP_ENDPOINT=https://www.skpr.com.au --name skpr-proxy skpr/proxy-app

Pull from DockerHub

Prepackaged images allow you to configure the container, and an image can be found on Docker Hub

$ docker pull skpr/proxy-app:latest
$  docker run --rm -p 7700:7700 -e PROXY_APP_ADDR=:7700 -e PROXY_APP_ENDPOINT=https://www.skpr.com.au --name skpr-proxy skpr/proxy-app

How do I know it's running?

An endpoint may not know how to handle a request with a different Hostname header. To test for a 200 status code, we'll include our Host header:

Example:

$ curl --HEAD -H "Host: www.skpr.com.au" localhost:7700
HTTP/1.1 200 OK
Age: 1
Cache-Control: public, max-age=0, must-revalidate
Content-Type: text/html; charset=UTF-8
Date: Wed, 04 Aug 2021 04:42:11 GMT
Etag: "4394817e42b2622c92718ec394e7a606-ssl"
Server: Netlify
Strict-Transport-Security: max-age=31536000
X-Nf-Request-Id: 01FC7QG2RWGWCKJRJKXH55TKQC

Licence

This project is licenced under GPLv3