Webhooks upon server shutdown or startup

[big-duckie]

Enhancement Type

A completely new feature

Describe the enhancement

The ability to call a webhook with a JSON payload upon server shutdown or start up. This would be useful for a status message in something like Discord.

[itzg]

Interesting idea. It would be implemented in https://github.com/itzg/mc-server-runner which wraps the Java process called by this image.

The only restriction I can think of so far is that the "server starting" webhook event could only be sent at the very beginning as the Java process is being executed. It won't indicate the server is actually ready to accept connections.

[itzg]

Design wise I'm thinking runner would be given

• URL to POST and the presence of that would imply webhook support is enabled
• List of environment variables to pull as server info, such as TYPE, VERSION, MOTD

The webhook json payload could then include

• Event type: starting, stopped, failed (when non-zero exit status)
• Exit status: present when type is failed
• Server info: object containing each env var and its value as a string