HTTP Proxy Logger

HTTP Proxy Logger is a small reverse proxy that prints incoming HTTP requests and outgoing responses to stdout. Bodies compressed with gzip, deflate, or br are automatically decompressed in the logs so that you can easily inspect them. The output uses ANSI colors similar to HTTPie: request and response lines, header names, and JSON or XML bodies are highlighted for readability.

Example output

[2021/05/05 03:50:44] --- REQUEST 3 ---

POST /mocking/contacts HTTP/1.1
Host: demo7704619.mockable.io
User-Agent: PostmanRuntime/7.28.0
Content-Length: 63
Accept: */*
Accept-Encoding: gzip, deflate, br
Cache-Control: no-cache
Content-Type: application/json
X-Forwarded-For: 172.17.0.1

{
    "firstName": "Stanislav",
    "lastName": "Deviatov"
}

[2021/05/05 03:50:44] --- RESPONSE 3 (201 Created) ---

HTTP/1.1 201 Created
Content-Length: 68
Access-Control-Allow-Origin: *
Content-Type: application/json; charset=UTF-8
Date: Wed, 05 May 2021 03:50:45 GMT
Server: Google Frontend
X-Cloud-Trace-Context: 83ac5937ae7ba8f3ef96ee941227b1b0

{
  "salesforceId": "a0C3L0000008ZSNUA2",
  "action": "updated"
}

Building

The project requires Go 1.23.

Build a binary

go build -o http-proxy-logger

Build a Docker image

docker build -t stn1slv/http-proxy-logger .

Running

Set the TARGET environment variable to the upstream server and optionally PORT for the listen address. These values can also be provided with the -target and -port flags which override the environment.

Use the -requests and -responses flags to control which messages are printed. Both default to true.

Use the -no-color flag to disable colored output and remove ANSI color codes from the logs, useful for redirecting output to files or when colors are not desired.

The tool automatically highlights JSON and XML bodies with syntax coloring and proper formatting while preserving important structural information like XML namespaces and namespace prefixes (e.g., soapenv:Envelope).

Local execution

./http-proxy-logger -target http://example.com -port 8888 -responses=false

To disable colored output:

./http-proxy-logger -target http://example.com -port 8888 -no-color=true

Docker

docker run --rm -it -p 8888:8888 \
  stn1slv/http-proxy-logger \
  -target http://demo7704619.mockable.io \
  -port 8888

Add -responses=false to log only requests or -requests=false to log only responses. Add -no-color=true to disable colored output. Flags -target and -port may be used instead of the corresponding environment variables.

The proxy will forward traffic to the target and log each request/response pair using the format shown above.

License

This project is licensed under the MIT License.