nutclient

This package provides a very simple NUT client for Go. Its current features include:

• Monitor for watching power events
• Automatic reconnection when disconnected
• Option for keep-alive commands to keep the socket open

Go 1.18 is the minimum supported version.

Basic Usage

To use the package in your program, begin by importing it:

import "github.com/nathan-osman/nutclient/v3"

Create a default Client instance for localhost using nutclient.New():

c := nutclient.New(nil)
defer c.Close()

The Config struct passed to New can be used to specify the address of the NUT server. It also allows you to specify the callbacks that will be invoked when power events occur:

c := nutclient.New(
    &nutclient.Config{
        Addr: "localhost:3493",
        ConnectedFn: func() {
            fmt.Println("Connected!")
        },
        DisconnectedFn: func() {
            fmt.Println("Disconnected!")
        },
    },
)
defer c.Close()

Once connected, you can use methods like Get() to interact with the NUT server. For example, to lookup the current battery status of the UPS named "ups", you would use:

v, err := c.Get("VAR", "ups", "ups.status")
if err != nil {
    // TODO: handle error
}
fmt.Printf("Battery: %s\n", v)

Monitoring a UPS

The monitor package simplifies the task of monitoring a UPS server for power events:

import "github.com/nathan-osman/nutclient/v3/monitor"

c := monitor.New(
    &monitor.Config{
        Addr: "localhost:3493",
        Name: "ups",
        PowerLostFn: func() {
            fmt.Println("Power lost!")
        },
        PowerRestoredFn: func() {
            fmt.Println("Power restored!")
        },
    },
)
defer c.Close()

Important Notes

NUT servers can be configured to drop open connections if no command is run after a certain timeout. Therefore, nutclient offers a KeepAliveInterval configuration option to run a no-op command:

&nutclient.Config{
    KeepAliveInterval: 30 * time.Second,
}

monitor.Config has this set by default.