adds configurable debugging of startup of processes and print out some info from the chrome viable() function for debugging purposes

cmd/gotenberg/main.go

@@ -25,6 +25,7 @@ const (
 	disableGoogleChromeEnvVar       = "DISABLE_GOOGLE_CHROME"
 	disableUnoconvEnvVar            = "DISABLE_UNOCONV"
 	disableHealthcheckLoggingEnvVar = "DISABLE_HEALTHCHECK_LOGGING"
+	debugProcessStartup             = "DEBUG_PROCESS_STARTUP"
 )
 
 func mustParseEnvVar() *api.Options {
@@ -49,37 +50,31 @@ func mustParseEnvVar() *api.Options {
 		}
 		opts.DefaultListenPort = v
 	}
-	if v, ok := os.LookupEnv(disableGoogleChromeEnvVar); ok {
+	//checkBoolEnv is a convenience function for reading an env var with a bool value where `1` is true and `0` is false
+	checkBoolEnv := func(name string) bool {
+		if v, ok := os.LookupEnv(name); ok {
 			if v != "1" && v != "0" {
-			notify.ErrPrint(fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %v", disableGoogleChromeEnvVar, v))
+				notify.ErrPrint(fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %v", name, v))
 				os.Exit(1)
 			}
-		opts.EnableChromeEndpoints = v != "1"
+			return v == "1"
 		}
-	if v, ok := os.LookupEnv(disableUnoconvEnvVar); ok {
-		if v != "1" && v != "0" {
-			notify.ErrPrint(fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %v", disableUnoconvEnvVar, v))
-			os.Exit(1)
-		}
-		opts.EnableUnoconvEndpoints = v != "1"
-	}
-	if v, ok := os.LookupEnv(disableHealthcheckLoggingEnvVar); ok {
-		if v != "1" && v != "0" {
-			notify.ErrPrint(fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %v", disableHealthcheckLoggingEnvVar, v))
-			os.Exit(1)
-		}
-		opts.EnableHealthcheckLogging = v != "1"
+		return false
 	}
+	opts.EnableChromeEndpoints = !checkBoolEnv(disableGoogleChromeEnvVar)
+	opts.EnableUnoconvEndpoints = !checkBoolEnv(disableUnoconvEnvVar)
+	opts.EnableHealthcheckLogging = !checkBoolEnv(disableHealthcheckLoggingEnvVar)
+	opts.DebugProcessStartup = checkBoolEnv(debugProcessStartup)
 	return opts
 }
 
 func mustStartProcesses(opts *api.Options) []pm2.Process {
 	var processes []pm2.Process
 	if opts.EnableChromeEndpoints {
-		processes = append(processes, pm2.NewChrome())
+		processes = append(processes, pm2.NewChrome(opts.DebugProcessStartup))
 	}
 	if opts.EnableUnoconvEndpoints {
-		processes = append(processes, pm2.NewUnoconv())
+		processes = append(processes, pm2.NewUnoconv(opts.DebugProcessStartup))
 	}
 	for _, p := range processes {
 		notify.Printf("starting %s with PM2...", p.Fullname())

internal/app/api/api.go

@@ -1,8 +1,6 @@
 package api
 
-import (
-	"github.com/labstack/echo/v4"
-)
+import "github.com/labstack/echo/v4"
 
 const pingEndpoint = "/ping"
 
@@ -14,6 +12,7 @@ type Options struct {
 	EnableChromeEndpoints    bool
 	EnableUnoconvEndpoints   bool
 	EnableHealthcheckLogging bool
+	DebugProcessStartup      bool
 }
 
 // DefaultOptions returns default options.

internal/pkg/pm2/chrome.go

@@ -7,15 +7,19 @@ import (
 	"github.com/mafredri/cdp/devtool"
 )
 
+const (
+	warmupTime = 10 * time.Second
+)
+
 type chrome struct {
 	manager *processManager
 }
 
 // NewChrome retruns a Google Chrome
 // headless process.
-func NewChrome() Process {
+func NewChrome(debug bool) Process {
 	return &chrome{
-		manager: &processManager{},
+		manager: &processManager{verbose: debug},
 	}
 }
 
@@ -58,12 +62,20 @@ 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
+	p.manager.notifyf(`%v: checking Chrome liveness via debug version endpoint 
+'http://localhost:9222/json/version'`, p.name())
+	v, err := devtool.New("http://localhost:9222").Version(ctx)
+	if err != nil {
+		p.manager.notifyf("%v: Chrome version endpoint returned error: %v", p.name(), err)
+		return false
+	}
+	p.manager.notifyf("%v: Chrome returned version info: %+v", p.name(), *v)
+	return true
 }
 
 func (p *chrome) warmup() {
-	time.Sleep(5 * time.Second)
+	p.manager.notifyf("%v: allowing Chrome %v to startup", p.name(), warmupTime)
+	time.Sleep(warmupTime)
 }
 
 // Compile-time checks to ensure type implements desired interfaces.

internal/pkg/pm2/chrome_test.go

@@ -7,13 +7,13 @@ import (
 )
 
 func TestChromeStart(t *testing.T) {
-	p := NewChrome()
+	p := NewChrome(false)
 	err := p.Start()
 	require.Nil(t, err)
 }
 
 func TestChromeShutdown(t *testing.T) {
-	p := NewChrome()
+	p := NewChrome(false)
 	err := p.Shutdown()
 	require.Nil(t, err)
 }

internal/pkg/pm2/pm2.go

@@ -1,8 +1,14 @@
 package pm2
 
 import (
+	"bufio"
 	"fmt"
+	"io"
 	"os/exec"
+	"strings"
+	"time"
+
+	"github.com/thecodingmachine/gotenberg/internal/pkg/notify"
 )
 
 const (
@@ -25,6 +31,7 @@ type Process interface {
 
 type processManager struct {
 	heuristicState int32
+	verbose        bool
 }
 
 func (m *processManager) start(p Process) error {
@@ -76,8 +83,43 @@ func (m *processManager) pm2(p Process, cmdName string) error {
 		"pm2",
 		cmdArgs...,
 	)
+	m.notifyf("executing command '%v'", strings.Join(cmd.Args, " "))
+	if m.verbose {
+		chromeStdErr, err := cmd.StderrPipe()
+		if err != nil {
+			return fmt.Errorf("failed getting Chrome stderr: %v", err)
+		}
+		chromeStdOut, err := cmd.StdoutPipe()
+		if err != nil {
+			return fmt.Errorf("failed getting Chrome stdout: %v", err)
+		}
+		readFromPipe := func(name string, reader io.ReadCloser) {
+			r := bufio.NewReader(reader)
+			defer reader.Close()
+			for {
+				line, _, err := r.ReadLine()
+				if err != nil {
+					if err != io.EOF {
+						m.notifyf("error reading from %v for process %v", name, p.name())
+					}
+					break
+				}
+				if len(line) != 0 {
+					m.notifyf("%v %v: %s", p.name(), name, string(line))
+				}
+			}
+		}
+		go readFromPipe("stdout", chromeStdOut)
+		go readFromPipe("stderr", chromeStdErr)
+	}
 	if err := cmd.Start(); err != nil {
 		return fmt.Errorf("%s %s with PM2: %v", cmdName, p.Fullname(), err)
 	}
 	return nil
 }
+
+func (m *processManager) notifyf(format string, args ...interface{}) {
+	if m.verbose {
+		notify.Printf(fmt.Sprintf("%v: %s", time.Now().Format(time.RFC3339), format), args...)
+	}
+}

internal/pkg/pm2/unoconv.go

@@ -6,9 +6,9 @@ type unoconv struct {
 
 // NewUnoconv retruns a unoconv listener
 // process.
-func NewUnoconv() Process {
+func NewUnoconv(debug bool) Process {
 	return &unoconv{
-		manager: &processManager{},
+		manager: &processManager{verbose: debug},
 	}
 }
 

internal/pkg/pm2/unoconv_test.go

@@ -7,13 +7,13 @@ import (
 )
 
 func TestUnoconvStart(t *testing.T) {
-	p := NewUnoconv()
+	p := NewUnoconv(false)
 	err := p.Start()
 	require.Nil(t, err)
 }
 
 func TestUnoconvShutdown(t *testing.T) {
-	p := NewUnoconv()
+	p := NewUnoconv(false)
 	err := p.Shutdown()
 	require.Nil(t, err)
 }