support systemd notifications

Fixes #1733

vendor/github.com/okzk/sdnotify/LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 okzk
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/okzk/sdnotify/README.md

@@ -0,0 +1,15 @@
+# sdnotify
+
+sd_notify utility for golang.
+
+## Installation
+
+    go get github.com/okzk/sdnotify
+
+## Example
+
+see [sample/main.go](sample/main.go)
+
+## License
+
+MIT

vendor/github.com/okzk/sdnotify/notify.go

@@ -0,0 +1,9 @@
+// +build !linux
+
+package sdnotify
+
+// SdNotify sends a specified string to the systemd notification socket.
+func SdNotify(state string) error {
+	// do nothing
+	return nil
+}

vendor/github.com/okzk/sdnotify/notify_linux.go

@@ -0,0 +1,23 @@
+package sdnotify
+
+import (
+	"net"
+	"os"
+)
+
+// SdNotify sends a specified string to the systemd notification socket.
+func SdNotify(state string) error {
+	name := os.Getenv("NOTIFY_SOCKET")
+	if name == "" {
+		return ErrSdNotifyNoSocket
+	}
+
+	conn, err := net.DialUnix("unixgram", nil, &net.UnixAddr{Name: name, Net: "unixgram"})
+	if err != nil {
+		return err
+	}
+	defer conn.Close()
+
+	_, err = conn.Write([]byte(state))
+	return err
+}

vendor/github.com/okzk/sdnotify/util.go

@@ -0,0 +1,39 @@
+package sdnotify
+
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrSdNotifyNoSocket is the error returned when the NOTIFY_SOCKET does not exist.
+var ErrSdNotifyNoSocket = errors.New("No socket")
+
+// Ready sends READY=1 to the systemd notify socket.
+func Ready() error {
+	return SdNotify("READY=1")
+}
+
+// Stopping sends STOPPING=1 to the systemd notify socket.
+func Stopping() error {
+	return SdNotify("STOPPING=1")
+}
+
+// Reloading sends RELOADING=1 to the systemd notify socket.
+func Reloading() error {
+	return SdNotify("RELOADING=1")
+}
+
+// Errno sends ERRNO=? to the systemd notify socket.
+func Errno(errno int) error {
+	return SdNotify(fmt.Sprintf("ERRNO=%d", errno))
+}
+
+// Status sends STATUS=? to the systemd notify socket.
+func Status(status string) error {
+	return SdNotify("STATUS=" + status)
+}
+
+// Watchdog sends WATCHDOG=1 to the systemd notify socket.
+func Watchdog() error {
+	return SdNotify("WATCHDOG=1")
+}

vendor/modules.txt

@@ -35,6 +35,9 @@ github.com/go-sql-driver/mysql
 github.com/gorilla/websocket
 # github.com/goshuirc/irc-go v0.0.0-20210318074529-bdc2c2cd2fef
 ## explicit
+# github.com/okzk/sdnotify v0.0.0-20180710141335-d9becc38acbd
+## explicit
+github.com/okzk/sdnotify
 # github.com/onsi/ginkgo v1.12.0
 ## explicit
 # github.com/onsi/gomega v1.9.0