从 NodeJS 关闭系统或停止 AWS EC2 实例

Question

I have AWS EC2 instances running Debian with systemd running Node as a service. (Hereinafter these instances are called the "Node servers".)

The Node servers are started by another instance (hereinafter called "the manager instance") that is permanently on.

When a Node server experiences some predefined period of inactivity, I want it to shut down automatically.

I am considering the following options:

1. (After sensing a period of inactivity in Node) execute a child_process in Node that runs the shutdown now command.
2. (After sensing a period of inactivity in Node) call AWS SDK's stopInstances with the instance's own resource ID.
3. Expose an HTTP GET endpoint called last-request-time on each Node server, which is periodically polled by a "manager instance", which then decides whether/when to call AWS SDK's stopInstances .

I am unsure which of these approaches to take and would appreciate any advice. Explicitly shutting down a machine from Node running on that same machine feels somehow inappropriate. But option 3 requires periodic HTTP polling, not to mention that it feels more risky to rely on another instance for auto-shutdown. (If the manager is down all the instances keep going.)

Or perhaps it is possible to get systemd to shut down the machine when a particular service exits with a particular code? This, if possible, would feel like the best solution as the Node process would only need to abort itself after the period of inactivity with a particular exit code.

Answer 1

You could create a lambda function that acts as an api and uses the SDK's stopInstances functionality. That would also allow you to make it have the full functionality of a "manager instance" and save even more on instances since it will only run when needed.

Or you could cut out the middle-man and migrate the "Node servers" to lambda. ( lambda documentation )