From ee0647d95905e72b110a4171f611c955145332d9 Mon Sep 17 00:00:00 2001
From: Cuong Manh Le <cuong@windscribe.com>
Date: Wed, 22 Mar 2023 19:08:18 +0700
Subject: [PATCH] Add support for procd

Fixes #332
---
 service_linux.go       |   9 +++
 service_procd_linux.go | 175 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 184 insertions(+)
 create mode 100644 service_procd_linux.go

diff --git a/service_linux.go b/service_linux.go
index cecbb703..0c95882a 100644
--- a/service_linux.go
+++ b/service_linux.go
@@ -71,6 +71,15 @@ func init() {
 			},
 			new: newRCSService,
 		},
+		linuxSystemService{
+			name:   "linux-procd",
+			detect: isProcd,
+			interactive: func() bool {
+				is, _ := isInteractive()
+				return is
+			},
+			new: newProcdService,
+		},
 		linuxSystemService{
 			name:   "unix-systemv",
 			detect: func() bool { return true },
diff --git a/service_procd_linux.go b/service_procd_linux.go
new file mode 100644
index 00000000..5dece5a4
--- /dev/null
+++ b/service_procd_linux.go
@@ -0,0 +1,175 @@
+// Copyright 2015 Daniel Theophanes.
+// Use of this source code is governed by a zlib-style
+// license that can be found in the LICENSE file.
+
+package service
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+	"strings"
+	"text/template"
+	"time"
+)
+
+func isProcd() bool {
+	if _, err := exec.LookPath("procd"); err == nil {
+		return true
+	}
+	return false
+}
+
+type procd struct {
+	*sysv
+	scriptPath string
+}
+
+func newProcdService(i Interface, platform string, c *Config) (Service, error) {
+	sv := &sysv{
+		i:        i,
+		platform: platform,
+		Config:   c,
+	}
+
+	p := &procd{
+		sysv:       sv,
+		scriptPath: "/etc/init.d/" + sv.Name,
+	}
+	return p, nil
+}
+
+func (p *procd) template() *template.Template {
+	customScript := p.Option.string(optionSysvScript, "")
+
+	if customScript != "" {
+		return template.Must(template.New("").Funcs(tf).Parse(customScript))
+	}
+	return template.Must(template.New("").Funcs(tf).Parse(procdScript))
+}
+
+func (p *procd) Install() error {
+	confPath, err := p.configPath()
+	if err != nil {
+		return err
+	}
+	_, err = os.Stat(confPath)
+	if err == nil {
+		return fmt.Errorf("Init already exists: %p", confPath)
+	}
+
+	f, err := os.Create(confPath)
+	if err != nil {
+		return err
+	}
+	defer f.Close()
+
+	path, err := p.execPath()
+	if err != nil {
+		return err
+	}
+
+	var to = &struct {
+		*Config
+		Path         string
+		LogDirectory string
+	}{
+		p.Config,
+		path,
+		p.Option.string(optionLogDirectory, defaultLogDirectory),
+	}
+
+	err = p.template().Execute(f, to)
+	if err != nil {
+		return err
+	}
+
+	if err = os.Chmod(confPath, 0755); err != nil {
+		return err
+	}
+
+	if err = os.Symlink(confPath, "/etc/rc.d/S50"+p.Name); err != nil {
+		return err
+	}
+	if err = os.Symlink(confPath, "/etc/rc.d/K02"+p.Name); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (p *procd) Uninstall() error {
+	if err := run(p.scriptPath, "disable"); err != nil {
+		return err
+	}
+	cp, err := p.configPath()
+	if err != nil {
+		return err
+	}
+	if err := os.Remove(cp); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (p *procd) Status() (Status, error) {
+	_, out, err := runWithOutput(p.scriptPath, "status")
+	if err != nil && !(err.Error() == "exit status 3") {
+		return StatusUnknown, err
+	}
+
+	switch {
+	case strings.HasPrefix(out, "running"):
+		return StatusRunning, nil
+	case strings.HasPrefix(out, "inactive"):
+		return StatusStopped, nil
+	default:
+		return StatusUnknown, ErrNotInstalled
+	}
+}
+
+func (p *procd) Start() error {
+	return run(p.scriptPath, "start")
+}
+
+func (p *procd) Stop() error {
+	return run(p.scriptPath, "stop")
+}
+
+func (p *procd) Restart() error {
+	err := p.Stop()
+	if err != nil {
+		return err
+	}
+	time.Sleep(50 * time.Millisecond)
+	return p.Start()
+}
+
+const procdScript = `#!/bin/sh /etc/rc.common
+USE_PROCD=1
+# After network starts
+START=21
+# Before network stops
+STOP=89
+cmd="{{.Path}}{{range .Arguments}} {{.|cmd}}{{end}}"
+name="{{.Name}}"
+pid_file="/var/run/${name}.pid"
+
+start_service() {
+    echo "Starting ${name}"
+    procd_open_instance
+    procd_set_param command ${cmd}
+
+    # respawn automatically if something died, be careful if you have an alternative process supervisor
+    # if process exits sooner than respawn_threshold, it is considered crashed and after 5 retries the service is stopped
+    # if process finishes later than respawn_threshold, it is restarted unconditionally, regardless of error code
+    # notice that this is literal respawning of the process, no in a respawn-on-failure sense
+    procd_set_param respawn ${respawn_threshold:-3600} ${respawn_timeout:-5} ${respawn_retry:-5}
+
+    procd_set_param stdout 1             # forward stdout of the command to logd
+    procd_set_param stderr 1             # same for stderr
+    procd_set_param pidfile ${pid_file}  # write a pid file on instance start and remove it on stop
+    procd_close_instance
+    echo "${name} has been started"
+}
+`