xperimental / goecho

Simple echo service for testing (for example orchestrators)

goecho

This is a simple HTTP server built in Go that suited us good in testing our orchestration so far. It will answer to every path and method and will echo information about the request back to the client.

Currently, it has the following endpoints:

• /metrics – prometheus metrics about the service
• /version – Version information
• /_ready - Readiness check
• /* – Echo handler (will echo information about the request back)

The echo handler understands one query parameter: "env". When set to any non-zero-length value the response will also contain the environment variables set for the server.

Installation

For our purposes we typically use the Docker image, which can be found on Docker Hub:

docker run --rm --interactive --tty --publish 8080:8080 xperimental/goecho:$TAG

If you have Go installed it is also very simple to build the binary yourself:

git clone https://github.com/xperimental/goecho.git
cd goecho
make build-binary

If you want to build the Docker image instead, download the sources and run the provided script:

git clone https://github.com/xperimental/goecho.git
cd goecho
make image

The image will be called "xperimental/goecho" and have a tag based on the git repository ("latest" if you have made any uncommitted changes).

Usage

Some configuration options can be either set by using command-line options or environment variables. If both are set, environment variables will override the command-line options:

Option	Environment Variable	Default	Description
-addr	LISTEN_ADDR	:8080	Address and port to listen on.
-allow-env	ALLOW_ENV		Allow retrieval of environment variables.
-graceful-delay	GRACEFUL_DELAY	2s	Delay between receiving a shutdown signal and starting shutdown.
-tls-cert	TLS_CERT		Path to TLS certificate file.
-tls-key	TLS_KEY		Path to TLS key file.

TLS Support

goecho will by default only run a HTTP server, but if you provide a TLS certificate and key either using command-line flags or environment variables it will instead provide a HTTPS server.

When TLS is enabled and TLS requests reach the server the echo handler will also return information about the TLS version and the hostname used for the connection.