New environment variables : DISABLE_HEALTHCHECK_LOGGING and DEFAULT_LISTEN_PORT (#78)

* skip logging when healthcheck url is called; closes #74 (#75)

Signed-off-by: Casey Kuhlman <casey@monax.io>

* Configure listen port via environment variable (#77)

* skip logging when healthcheck url is called; closes #74

Signed-off-by: Casey Kuhlman <casey@monax.io>

* skip logging when healthcheck url is called; closes #74

Signed-off-by: Casey Kuhlman <casey@monax.io>

* adds the ability to establish the listen port via env var

Signed-off-by: Casey Kuhlman <casey@monax.io>

* minor refactoring of @compleatang work

* fixing typo

build/docs/content/03-environment-variables.md

@@ -13,7 +13,6 @@ It takes the strings `"0"` or `"1"` as value.
 > If Google Chrome is disabled, the following conversions will **not** be available anymore:
 > [HTML](#html), [URL](#url) and [Markdown](#markdown)
 
-
 ## Disable LibreOffice (unoconv)
 
 You may also disable LibreOffice (unoconv) with `DISABLE_UNOCONV`.
@@ -30,4 +29,20 @@ You may customize this timeout thanks to the environment variable `DEFAULT_WAIT_
 It takes a string representation of a float as value (e.g `"2.5"` for 2.5 seconds).
 
 > The default timeout may also be overridden per request thanks to the form field `waitTimeout`.
-> See the [timeout section](#timeout).
+> See the [timeout section](#timeout).
+
+## Disable logging on healthcheck
+
+By default, the API will add a log entry when the [healthcheck endpoint](#ping) is called.
+
+You may turn off this logging so as to avoid unnecessary entries in your logs with the environment variable `DISABLE_HEALTHCHECK_LOGGING`.
+
+This environment variable operates in the same manner as the `DISABLE_GOOGLE_CHROME` and `DISABLE_UNOCONV` variables operate in that it accepts the strings `"0"` or `"1"` as values. 
+
+## Default listen port
+
+By default, the API will listen on port `3000`. For most use cases this is perfectly fine, but at times there may be cases where you need to change this due to port conflicts.
+
+You may customize this port location with the environment variable `DEFAULT_LISTEN_PORT`.
+
+This environment variable accepts any string that can be turned into a port number (e.g., the string `"0"` up to the string `"65535"`).

cmd/gotenberg/main.go

@@ -20,9 +20,11 @@ import (
 var version = "snapshot"
 
 const (
-	defaultWaitTimeoutEnvVar  = "DEFAULT_WAIT_TIMEOUT"
-	disableGoogleChromeEnvVar = "DISABLE_GOOGLE_CHROME"
-	disableUnoconvEnvVar      = "DISABLE_UNOCONV"
+	defaultWaitTimeoutEnvVar        = "DEFAULT_WAIT_TIMEOUT"
+	defaultListenPortEnvVar         = "DEFAULT_LISTEN_PORT"
+	disableGoogleChromeEnvVar       = "DISABLE_GOOGLE_CHROME"
+	disableUnoconvEnvVar            = "DISABLE_UNOCONV"
+	disableHealthcheckLoggingEnvVar = "DISABLE_HEALTHCHECK_LOGGING"
 )
 
 func mustParseEnvVar() *api.Options {
@@ -35,6 +37,18 @@ func mustParseEnvVar() *api.Options {
 		}
 		opts.DefaultWaitTimeout = defaultWaitTimeout
 	}
+	if v, ok := os.LookupEnv(defaultListenPortEnvVar); ok {
+		defaultListener, err := strconv.ParseUint(os.Getenv(defaultListenPortEnvVar), 10, 64)
+		if err != nil {
+			notify.ErrPrint(fmt.Errorf("%s: wrong value: want uint got %v", defaultListenPortEnvVar, err))
+			os.Exit(1)
+		}
+		if defaultListener > 65535 {
+			notify.ErrPrint(fmt.Errorf("%s: wrong value: want uint < 65535 got %v", defaultListenPortEnvVar, defaultListener))
+			os.Exit(1)
+		}
+		opts.DefaultListenPort = v
+	}
 	if v, ok := os.LookupEnv(disableGoogleChromeEnvVar); ok {
 		if v != "1" && v != "0" {
 			notify.ErrPrint(fmt.Errorf("%s: wrong value: want \"0\" or \"1\" got %v", disableGoogleChromeEnvVar, v))
@@ -49,6 +63,13 @@ func mustParseEnvVar() *api.Options {
 		}
 		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 opts
 }
 
@@ -70,9 +91,9 @@ func mustStartProcesses(opts *api.Options) []pm2.Process {
 	return processes
 }
 
-func mustStartAPI(srv *echo.Echo) {
-	notify.Print("http server started on port 3000")
-	if err := srv.Start(":3000"); err != nil {
+func mustStartAPI(srv *echo.Echo, port string) {
+	notify.Printf("http server started on port %v", port)
+	if err := srv.Start(fmt.Sprintf(":%v", port)); err != nil {
 		if err != http.ErrServerClosed {
 			notify.ErrPrint(err)
 			os.Exit(1)
@@ -110,7 +131,7 @@ func main() {
 	processes := mustStartProcesses(opts)
 	// run our API in a goroutine so that it doesn't block.s
 	go func() {
-		mustStartAPI(srv)
+		mustStartAPI(srv, opts.DefaultListenPort)
 	}()
 	quit := make(chan os.Signal, 1)
 	// we'll accept graceful shutdowns when quit via SIGINT (Ctrl+C)

docs/index.html

@@ -255,6 +255,26 @@ Gotenberg API is available at <a href="http://localhost:3000">http://localhost:3
 See the <a href="#timeout">timeout section</a>.</p>
 </blockquote>
 
+<h2 class="Heading"><a class="Anchor" aria-hidden="true" id="environment_variables.disable_logging_on_healthcheck" href="#environment_variables.disable_logging_on_healthcheck">
+	<svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-link"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg>
+</a>Disable logging on healthcheck</h2>
+
+<p>By default, the API will add a log entry when the <a href="#ping">healthcheck endpoint</a> is called.</p>
+
+<p>You may turn off this logging so as to avoid unnecessary entries in your logs with the environment variable <code>DISABLE_HEALTHCHECK_LOGGING</code>.</p>
+
+<p>This environment variable operates in the same manner as the <code>DISABLE_GOOGLE_CHROME</code> and <code>DISABLE_UNOCONV</code> variables operate in that it accepts the strings <code>&#34;0&#34;</code> or <code>&#34;1&#34;</code> as values.</p>
+
+<h2 class="Heading"><a class="Anchor" aria-hidden="true" id="environment_variables.default_listen_port" href="#environment_variables.default_listen_port">
+	<svg xmlns="http://www.w3.org/2000/svg" aria-hidden="true" width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" class="feather feather-link"><path d="M10 13a5 5 0 0 0 7.54.54l3-3a5 5 0 0 0-7.07-7.07l-1.72 1.71"></path><path d="M14 11a5 5 0 0 0-7.54-.54l-3 3a5 5 0 0 0 7.07 7.07l1.71-1.71"></path></svg>
+</a>Default listen port</h2>
+
+<p>By default, the API will listen on port <code>3000</code>. For most use cases this is perfectly fine, but at times there may be cases where you need to change this due to port conflicts.</p>
+
+<p>You may customize this port location with the environment variable <code>DEFAULT_LISTEN_PORT</code>.</p>
+
+<p>This environment variable accepts any string that can be turned into a port number (e.g., the string <code>&#34;0&#34;</code> up to the string <code>&#34;65535&#34;</code>).</p>
+
               </div>
             
               <div class="Page" id="html">

internal/app/api/api.go

@@ -2,23 +2,28 @@ package api
 
 import (
 	"github.com/labstack/echo/v4"
-	"github.com/labstack/echo/v4/middleware"
 )
 
+const pingEndpoint = "/ping"
+
 // Options allows to customize the behaviour
 // of the API.
 type Options struct {
-	DefaultWaitTimeout     float64
-	EnableChromeEndpoints  bool
-	EnableUnoconvEndpoints bool
+	DefaultWaitTimeout       float64
+	DefaultListenPort        string
+	EnableChromeEndpoints    bool
+	EnableUnoconvEndpoints   bool
+	EnableHealthcheckLogging bool
 }
 
 // DefaultOptions returns default options.
 func DefaultOptions() *Options {
 	return &Options{
-		DefaultWaitTimeout:     10,
-		EnableChromeEndpoints:  true,
-		EnableUnoconvEndpoints: true,
+		DefaultWaitTimeout:       10,
+		DefaultListenPort:        "3000",
+		EnableChromeEndpoints:    true,
+		EnableUnoconvEndpoints:   true,
+		EnableHealthcheckLogging: true,
 	}
 }
 
@@ -27,8 +32,8 @@ func New(opts *Options) *echo.Echo {
 	api := echo.New()
 	api.HideBanner = true
 	api.HidePort = true
-	api.Use(middleware.Logger())
-	api.GET("/ping", func(c echo.Context) error { return nil })
+	api.Use(handleLogging(opts.EnableHealthcheckLogging))
+	api.GET(pingEndpoint, func(c echo.Context) error { return nil })
 	g := api.Group("/convert")
 	g.Use(handleContext(opts))
 	g.Use(handleError())

internal/app/api/middleware.go

@@ -6,8 +6,22 @@ import (
 	"strings"
 
 	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
 )
 
+func handleLogging(enableHealthcheckLogging bool) echo.MiddlewareFunc {
+	if enableHealthcheckLogging {
+		// default logging middleware.
+		return middleware.Logger()
+	}
+	// middleware for skipping logging when the ping endpoint is called.
+	return middleware.LoggerWithConfig(middleware.LoggerConfig{
+		Skipper: func(c echo.Context) bool {
+			return c.Request().URL.Path == pingEndpoint
+		},
+	})
+}
+
 func handleContext(opts *Options) echo.MiddlewareFunc {
 	// middleware for extending default context with our
 	// custom constext.