echo-server

A simple HTTP server that echoes request details back as JSON. Useful to test and debug HTTP clients, proxies and ingress rules.

Docker Registries

Images are published for linux/amd64 and linux/arm64.

• Docker Hub
• AWS ECR Public
• Github Docker Registry

Usage

docker run --rm -p 5000:5000 -e APP_NAME=robinho robsonpeixoto/echo-server

Or without Docker:

go run .

In another terminal:

❯ curl -s 'localhost:5000/hello?name=robinho' | jq
{
  "host": "localhost:5000",
  "proto": "HTTP/1.1",
  "content_length": 0,
  "headers": {
    "User-Agent": ["curl/8.18.0"],
    "Accept": ["*/*"]
  },
  "form": {},
  "query": {
    "name": ["robinho"]
  },
  "remote": {
    "address": "172.17.0.1",
    "port": "34508"
  },
  "path": "/hello",
  "method": "GET",
  "extras": {
    "app_name": "robinho"
  }
}

JSON bodies are echoed under json, and URL-encoded forms under form:

❯ curl -s -H 'Content-Type: application/json' -d '{"message":"hi"}' localhost:5000 | jq .json
{
  "message": "hi"
}

❯ curl -s -d 'user=robinho' localhost:5000 | jq .form
{
  "user": ["robinho"]
}

A request with Content-Type: application/json and an invalid body returns 400.

Configuration

Env / flag	Default	Description
PORT	5000	Port to listen on
APP_NAME		Returned as extras.app_name
SHOW_ENVS		When 1, returns all env vars in extras.envs
-version		Print version and commit, then exit

Warning

SHOW_ENVS=1 exposes every environment variable, including secrets, to anyone who can reach the server.