up

Hey, you up?

up checks if a local server is healthy by performing an HTTP GET request at the specified path and port. If the server responds with a 200 OK, up exits with a 0 status code. Otherwise, up exits with a 1 status code, indicating the health check has failed.

Why is this useful? Amazon ECS provides support for health checking of containers defined in ECS Tasks, but it does not provide a client, nor the facilities, to perform the health check request. Instead, users must add a client, such as curl, to their container image in order to support the health check. curl is an amazing tool, but quite a bit more than whats necessary for a simple health check. Therefore, up was created - to simply ask "Hey, you up?"

Usage

By default, up checks for a HTTP 200 OK response on localhost port 80 at the path /healthz. The port and/or path, can be changed via environment variables or arguments.

Environment Variables

UP_PATH and UP_PORT environment variables will modify the path and port that up checks.

UP_PATH=/healthy UP_PORT=3000 up

Arguments

Using arguments, the first argument is the path, and the second argument is the port:

up --port 3000 --path /healthy

You can mix and match environment variables and arguments - environment variables will take precedence over arguments.