5.0.0 (#66)

internal/pkg/pm2/chrome.go

@@ -2,30 +2,36 @@ package pm2
 
 import (
 	"context"
-	"fmt"
 	"time"
 
 	"github.com/mafredri/cdp/devtool"
-	"github.com/thecodingmachine/gotenberg/internal/pkg/notify"
 )
 
-// Chrome facilitates starting or shutting down
-// Chrome headless with PM2.
-type Chrome struct{}
-
-// Launch starts Chrome headless with PM2.
-func (c *Chrome) Launch() error {
-	return launch(c)
+type chrome struct {
+	manager *processManager
 }
 
-// Shutdown stops Chrome headless and
-// removes it from the list of PM2
-// processes.
-func (c *Chrome) Shutdown() error {
-	return shutdown(c)
+// NewChrome retruns a Google Chrome
+// headless process.
+func NewChrome() Process {
+	return &chrome{
+		manager: &processManager{},
+	}
 }
 
-func (c *Chrome) getArgs() []string {
+func (p *chrome) Fullname() string {
+	return "Google Chrome headless"
+}
+
+func (p *chrome) Start() error {
+	return p.manager.start(p)
+}
+
+func (p *chrome) Shutdown() error {
+	return p.manager.shutdown(p)
+}
+
+func (p *chrome) args() []string {
 	return []string{
 		"--no-sandbox",
 		"--headless",
@@ -44,28 +50,23 @@ func (c *Chrome) getArgs() []string {
 	}
 }
 
-func (c *Chrome) getName() string {
+func (p *chrome) name() string {
 	return "google-chrome-stable"
 }
 
-func (c *Chrome) getFullname() string {
-	return "Chrome headless"
-}
-
-func (c *Chrome) isViable() bool {
-	// check if Chrome is correctly running.
+func (p *chrome) viable() bool {
+	// check if Google Chrome is correctly running.
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	_, err := devtool.New("http://localhost:9222").Version(ctx)
 	return err == nil
 }
 
-func (c *Chrome) warmup() {
-	notify.Println(fmt.Sprintf("warming-up %s", c.getFullname()))
+func (p *chrome) warmup() {
 	time.Sleep(5 * time.Second)
 }
 
 // Compile-time checks to ensure type implements desired interfaces.
 var (
-	_ = Process(new(Chrome))
+	_ = Process(new(chrome))
 )

internal/pkg/pm2/chrome_test.go

@@ -6,14 +6,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestChromeLaunch(t *testing.T) {
-	p := &Chrome{}
-	err := p.Launch()
+func TestChromeStart(t *testing.T) {
+	p := NewChrome()
+	err := p.Start()
 	require.Nil(t, err)
 }
 
 func TestChromeShutdown(t *testing.T) {
-	p := &Chrome{}
+	p := NewChrome()
 	err := p.Shutdown()
 	require.Nil(t, err)
 }

internal/pkg/pm2/doc.go

@@ -2,7 +2,7 @@
 Package pm2 facilitates starting external
 processes on which our API depends.
 
-For instance, it starts Chrome headless and
+For instance, it may start Google Chrome headless and
 unoconv listener with PM2.
 
 The PM2 process manager launch those processes and keep

internal/pkg/pm2/pm2.go

@@ -3,69 +3,81 @@ package pm2
 import (
 	"fmt"
 	"os/exec"
-
-	"github.com/thecodingmachine/gotenberg/internal/pkg/notify"
 )
 
-// Process is a type that can launch or
+const (
+	stoppedState = iota
+	runningState
+	errorState
+)
+
+// Process is a type that can start or
 // shutdown a process with PM2.
 type Process interface {
-	Launch() error
+	Fullname() string
+	Start() error
 	Shutdown() error
-	getArgs() []string
-	getName() string
-	getFullname() string
-	isViable() bool
+	args() []string
+	name() string
+	viable() bool
 	warmup()
 }
 
-const maxRestartAttempts int = 5
-
-var humanNames = map[string]string{
-	"start":   "started",
-	"restart": "restarted",
-	"stop":    "stopped",
+type processManager struct {
+	heuristicState int32
 }
 
-func launch(p Process) error {
-	if err := run(p, "start"); err != nil {
+func (m *processManager) start(p Process) error {
+	if err := m.pm2(p, "start"); err != nil {
 		return err
 	}
 	p.warmup()
-	if !p.isViable() {
+	if !p.viable() {
 		attempts := 0
-		for attempts < maxRestartAttempts && !p.isViable() {
-			run(p, "restart")
+		for attempts < 5 && !p.viable() {
+			if err := m.pm2(p, "restart"); err != nil {
+				m.heuristicState = errorState
+				return err
+			}
 			p.warmup()
 			attempts++
 		}
-		if !p.isViable() {
-			return fmt.Errorf("failed to launch %s", p.getFullname())
+		if !p.viable() {
+			m.heuristicState = errorState
+			return fmt.Errorf("failed to launch %s", p.Fullname())
 		}
 	}
+	m.heuristicState = runningState
 	return nil
 }
 
-func shutdown(p Process) error {
-	return run(p, "stop")
+func (m *processManager) shutdown(p Process) error {
+	if m.heuristicState != runningState {
+		return nil
+	}
+	if err := m.pm2(p, "stop"); err != nil {
+		m.heuristicState = errorState
+		return err
+	}
+	m.heuristicState = stoppedState
+	return nil
 }
 
-func run(p Process, cmdName string) error {
+func (m *processManager) pm2(p Process, cmdName string) error {
 	cmdArgs := []string{
 		cmdName,
-		p.getName(),
+		p.name(),
 	}
 	if cmdName == "start" {
 		cmdArgs = append(cmdArgs, "--interpreter none", "--")
-		cmdArgs = append(cmdArgs, p.getArgs()...)
+		cmdArgs = append(cmdArgs, p.args()...)
 	}
 	cmd := exec.Command(
 		"pm2",
 		cmdArgs...,
 	)
 	if err := cmd.Start(); err != nil {
-		return fmt.Errorf("%s %s with PM2: %v", cmdName, p.getFullname(), err)
+		return fmt.Errorf("%s %s with PM2: %v", cmdName, p.Fullname(), err)
 	}
-	notify.Println(fmt.Sprintf("%s %s with PM2", p.getFullname(), humanNames[cmdName]))
 	return nil
 }

internal/pkg/pm2/unoconv.go

@@ -1,47 +1,52 @@
 package pm2
 
-// Unoconv facilitates starting or shutting down
-// unoconv listener with PM2.
-type Unoconv struct{}
-
-// Launch starts unoconv listener with PM2.
-func (u *Unoconv) Launch() error {
-	return launch(u)
+type unoconv struct {
+	manager *processManager
 }
 
-// Shutdown stops unoconv listener and
-// removes it from the list of PM2
-// processes.
-func (u *Unoconv) Shutdown() error {
-	return shutdown(u)
+// NewUnoconv retruns a unoconv listener
+// process.
+func NewUnoconv() Process {
+	return &unoconv{
+		manager: &processManager{},
+	}
 }
 
-func (u *Unoconv) getArgs() []string {
+func (p *unoconv) Fullname() string {
+	return "unoconv listener"
+}
+
+func (p *unoconv) Start() error {
+	return p.manager.start(p)
+}
+
+func (p *unoconv) Shutdown() error {
+	return p.manager.shutdown(p)
+}
+
+func (p *unoconv) args() []string {
 	return []string{
 		"--listener",
 		"--verbose",
 	}
 }
 
-func (u *Unoconv) getName() string {
+func (p *unoconv) name() string {
 	return "unoconv"
 }
 
-func (u *Unoconv) getFullname() string {
-	return "unoconv listener"
-}
-
-func (u *Unoconv) isViable() bool {
+func (p *unoconv) viable() bool {
 	// TODO find a way to check if
-	// unoconv is correctly started?
+	// the unoconv listener
+	// is correctly started?
 	return true
 }
 
-func (u *Unoconv) warmup() {
+func (p *unoconv) warmup() {
 	// let's do nothing.
 }
 
 // Compile-time checks to ensure type implements desired interfaces.
 var (
-	_ = Process(new(Unoconv))
+	_ = Process(new(unoconv))
 )

internal/pkg/pm2/unoconv_test.go

@@ -6,14 +6,14 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func TestUnoconvLaunch(t *testing.T) {
-	p := &Unoconv{}
-	err := p.Launch()
+func TestUnoconvStart(t *testing.T) {
+	p := NewUnoconv()
+	err := p.Start()
 	require.Nil(t, err)
 }
 
 func TestUnoconvShutdown(t *testing.T) {
-	p := &Unoconv{}
+	p := NewUnoconv()
 	err := p.Shutdown()
 	require.Nil(t, err)
 }