open-consul/agent/systemd/notify.go

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// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: MPL-2.0
package systemd
import (
"errors"
"net"
"os"
)
const (
// magic values for systemd
// from https://www.freedesktop.org/software/systemd/man/sd_notify.html#Description
Ready = "READY=1"
Reloading = "RELOADING=1"
Stopping = "STOPPING=1"
)
var NotifyNoSocket = errors.New("No socket")
// Notifier provides a method to send a message to systemd.
type Notifier struct{}
// Notify sends a message to the init daemon. It is common to ignore the error.
func (n *Notifier) Notify(state string) error {
addr := &net.UnixAddr{
Name: os.Getenv("NOTIFY_SOCKET"),
Net: "unixgram",
}
if addr.Name == "" {
return NotifyNoSocket
}
conn, err := net.DialUnix(addr.Net, nil, addr)
if err != nil {
return err
}
defer conn.Close()
_, err = conn.Write([]byte(state))
return err
}