sgrodriguez / reverse-proxy

An example of a reverse proxy written in go using std lib

Reverse Proxy

Description

In addition to fulfilling the typical functionality of a reverse proxy, this tool is capable of blocking requests based on a specified list of blockers. Additionally, it has the functionality to conceal sensitive information in the response body. Notably, this feature is applied exclusively to the response of GET requests.

Features

• Configuration file-based setting of blockers.
• Blocker list includes MethodBlocker, PathBlocker, ParamBlocker, and HeaderBlocker.
• Includes two maskers: CreditCardMasker, EmailMasker.
• Easy to extend with new blockers and maskers.
• Log all incoming requests and responses in human-readable format.
• Simple, only use standard library besides a logger.
• Graceful shutdown.
• Support for https target servers.

How to Set Up

Prerequisites

• Golang >1.19

Configuration

The app uses a configuration file in TOML format. The configuration path is set with -config command option when running the app. The app will use an example configuration file in internal/config/example_config.toml if not provided.

Toml example

TargetURL = "http://localhost:8080"
ReverseProxyPort = 8081
[HeaderBlocker]
  [HeaderBlocker.HeaderMap]
    X-Blocker = "Block"
    Authorization = "Secret"
[ParamBlocker]
  [ParamBlocker.ParamsMap]
    apikey = "token"
[PathBlocker]
  path = ["/admin", "/private"]
[MethodBlocker]
  method = ["POST", "PUT"]

Build the app

make build

And then run the app with the configuration file path

./reverse-proxy -config /folder/config.toml

Run the examples

Run the example to test against a mock target server:

make example

After running make example, you can test the reverse proxy with the target_server_example located in test/ folder.

curl -X GET -v http://localhost:8081/get 

Run the tests

make tests

Future Work - Nice To Have

• In order to be production ready it needs more work with:
  • Streaming.
  • Websockets.
  • Compresses data.
  • More testing with the mask to avoid leaks.
• Healthcheck, readiness endpoint.
• Expose the reverse proxy with TLS support.
• Add Timeout configuration to the reverse proxy.
• Metrics.
• Benchmarking and performance testing:
  • Improve the mask regexes with others libs hyperscan re2
  • Check blockers concurrently.
• Add more test cases of strange and edge cases.

Contributors

• sgrodriguez