static-response-server

Super tiny HTTP server that always returns the same response.

Purpose

After decommissioning a service, you may want to keep something online and responding to HTTP requests letting users know the service no longer exists. This is especially useful if legacy code is still hitting an API endpoint and completely taking that offline might break consumers.

Instead of spinning up a full blown HTTP server like nginx to handle this, you can instead use this super tiny, statically-compiled Golang-based Docker image which uses as few resources as possible.

Installation

Docker

The easiest way to use this server is via Docker:

docker run -d -p 80:8080 colinodell/static-response-server --code=404 --body="Not Found" --headers="Content-Type: text/plain" -v

Or with environment variables:

docker run -d -p 80:8080 -e HTTP_CODE=404 -e HTTP_BODY="Not Found" -e HTTP_HEADERS="Content-Type: text/plain" -e HTTP_VERBOSE=1 colinodell/static-response-server

Using Docker-Compose? We've got that covered too!

version: '3'
services:
  static-response-server:
    image: colinodell/static-response-server
    ports:
      - "80:8080"
    environment:
      - HTTP_CODE=404
      - HTTP_BODY="Not Found"
      - HTTP_HEADERS="Content-Type: text/plain"
      - HTTP_VERBOSE=1

(Consider using a reverse proxy like Traefik to secure the requests with HTTPS.)

Build From Source

Simply clone this project and run go build to build the binary.

Configuration

The server can be configured via command line flags or environment variables:

Flag	Environment Variable	Default	Description
--port or -p	HTTP_PORT	8080	Port to listen on
--code	HTTP_CODE	200	HTTP status code to return
--body	HTTP_BODY		HTTP body to return
--headers	HTTP_HEADERS		HTTP headers to return (multiple headers separated by pipes (|)
--verbose or -v	VERBOSE	(off)	Print verbose output

$ ./static-response-server --help

usage: static-response-server [<flags>]

    Flags:
    --help           Show context-sensitive help (also try --help-long and --help-man).
    -p, --port=8080  Port to listen on
    --headers=""     Headers to add to the response
    --code=200       HTTP status code to return
    --body=""        Body to return
    -v, --verbose    Verbose logging

Examples

Returning a 404

./static-response-server --body "This service no longer exists" --code 404

Returning a 404 (using environment variables)

HTTP_BODY="This service no longer exists" HTTP_CODE=404 ./static-response-server

Redirecting all traffic to a different URL

./static-response-server --body "Moved Permanently" --code 301 --headers "Location: https://www.google.com"

Pretending your API still accepts POST requests

./static-response-server --code 201