TLSrproxy

A body-rewriting (hijacking) golang reverse proxy.

TLSrproxy is a proxy server that replaces strings in request and responses, it serves as a sandbox for debugging mixed-content errors, it uses a yaml config file which can be overrided by environment variaboles.

Environment Variables for Configuration

• SERVER_HTTP_ADDR: The host and port. Default: ":8888"

• SERVER_CERT: Path to cert file. Default: ""

• CERT_KEY: Path to key file. Default: ""

• SERVER_DRAIN: How long application will wait to drain old requests before restarting. Default: "1s"

• PROXY_UPSTREAM Forward incoming requests to this host.

Example:

Setting up a proxy to httpbin.org and post a json.

$ docker run -it --rm -e PROXY_UPSTREAM=https://httpbin.org -p8888:8888 quay.io/jfardello/tlsrproxy:latest
INFO[0000] Running HTTP server on :8888                 
INFO[0000] Forwarding to upstream on https://httpbin.org 
Warning! Serving clear text http!

On another terminal..

(it should change "http://" for "https://")

$curl -i  -H 'X-foo: bart' http://localhost:8888/anything/barbar/barbar
HTTP/1.1 200 OK
Access-Control-Allow-Credentials: true
Access-Control-Allow-Origin: *
Content-Length: 424
Content-Type: application/json
Date: Mon, 28 Dec 2020 20:57:13 GMT
Server: gunicorn/19.9.0

{
  "args": {}, 
  "data": "", 
  "files": {}, 
  "form": {}, 
  "headers": {
    "Accept": "*/*", 
    "Accept-Encoding": "gzip", 
    "Host": "httpbin.org", 
    "User-Agent": "curl/7.69.1", 
    "X-Amzn-Trace-Id": "Root=1-5fea46a9-5bc577145bbcc9195c73730d", 
    "X-Foo": "bert"
  }, 
  "json": null, 
  "method": "GET", 
  "origin": "127.0.0.1, 88.53.64.95", 
  "url": "https://httpbin.org/anything/pepepeo/pepepeo"
}

Customizing the default config file

It should be overrided in a volume, to get the file from the image:

mkdir config
docker run -it --rm --entrypoint cat quai.io/jfardello/tlsrproxy /config/tlsrproxy.yaml > /config/tlsrproxy.yaml

After editing config/tlsrproxy.yaml you can launch the same docker command with a volume (or attach a permanent one)

docker run -it --rm -v ./config:/config -e PROXY_UPSTREAM=https://httpbin.org -p8888:8888 quay.io/jfardello/tlsrproxy:latest

Default config file

server:
  cert: ""
  key: ""
  drain: 1s
proxy:
  upstream: http://localhost:9090
  #Replaces body strings we get from upstream.
  replaces:
    request: #Replaces the headers we send.
      headers: 
        - - bart
          - bert
    response: #Replaces the content in the response.
      mimes: #Only deal with this types (Dont break downloads or othe content.)
      - text/html
      - text/css
      - application/javascript
      - application/json
      - application/xhtml+xml
      body:
        - - http://
          - https://
        - - barbar
          - pepepeo
      headers:
        - - header1
          - header2
        - - headerA
          - headerB

Monitoring endpoint

/_health/status