feat(api): add basic auth support

pkg/modules/api/api.go

@@ -5,9 +5,7 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
-	"os"
 	"sort"
-	"strconv"
 	"strings"
 	"time"
 
@@ -34,6 +32,8 @@ type Api struct {
 	timeout                   time.Duration
 	rootPath                  string
 	traceHeader               string
+	basicAuthUsername         string
+	basicAuthPassword         string
 	disableHealthCheckLogging bool
 
 	routes              []Route
@@ -163,8 +163,8 @@ func (a *Api) Descriptor() gotenberg.ModuleDescriptor {
 			fs.Duration("api-timeout", time.Duration(30)*time.Second, "Set the time limit for requests")
 			fs.String("api-root-path", "/", "Set the root path of the API - for service discovery via URL paths")
 			fs.String("api-trace-header", "Gotenberg-Trace", "Set the header name to use for identifying requests")
+			fs.Bool("api-enable-basic-auth", false, "Enable basic authentication - will look for the GOTENBERG_API_BASIC_AUTH_USERNAME and GOTENBERG_API_BASIC_AUTH_PASSWORD environment variables")
 			fs.Bool("api-disable-health-check-logging", false, "Disable health check logging")
-
 			return fs
 		}(),
 		New: func() gotenberg.Module { return new(Api) },
@@ -184,24 +184,28 @@ func (a *Api) Provision(ctx *gotenberg.Context) error {
 	// Port from env?
 	portEnvVar := flags.MustString("api-port-from-env")
 	if portEnvVar != "" {
-		val, ok := os.LookupEnv(portEnvVar)
-
-		if !ok {
-			return fmt.Errorf("environment variable '%s' does not exist", portEnvVar)
-		}
-
-		if val == "" {
-			return fmt.Errorf("environment variable '%s' is empty", portEnvVar)
-		}
-
-		port, err := strconv.Atoi(val)
+		port, err := gotenberg.IntEnv(portEnvVar)
 		if err != nil {
-			return fmt.Errorf("get int value of environment variable '%s': %w", portEnvVar, err)
+			return fmt.Errorf("get API port from env: %w", err)
 		}
-
 		a.port = port
 	}
 
+	// Enable basic auth?
+	enableBasicAuth := flags.MustBool("api-enable-basic-auth")
+	if enableBasicAuth {
+		basicAuthUsername, err := gotenberg.StringEnv("GOTENBERG_API_BASIC_AUTH_USERNAME")
+		if err != nil {
+			return fmt.Errorf("get basic auth username from env: %w", err)
+		}
+		basicAuthPassword, err := gotenberg.StringEnv("GOTENBERG_API_BASIC_AUTH_PASSWORD")
+		if err != nil {
+			return fmt.Errorf("get basic auth password from env: %w", err)
+		}
+		a.basicAuthUsername = basicAuthUsername
+		a.basicAuthPassword = basicAuthPassword
+	}
+
 	// Get routes from modules.
 	mods, err := ctx.Modules(new(Router))
 	if err != nil {
@@ -394,6 +398,13 @@ func (a *Api) Start() error {
 		loggerMiddleware(a.logger, disableLoggingForPaths),
 	)
 
+	// Basic auth?
+	if a.basicAuthUsername != "" {
+		a.srv.Pre(
+			basicAuthMiddleware(a.basicAuthUsername, a.basicAuthPassword),
+		)
+	}
+
 	// Add the modules' middlewares in their respective stacks.
 	var externalMultipartMiddlewares []Middleware
 	for _, externalMiddleware := range a.externalMiddlewares {

pkg/modules/api/api_test.go

@@ -58,10 +58,28 @@ func TestApi_Provision(t *testing.T) {
 			expectError: true,
 		},
 		{
-			scenario: "port from env: empty environment variable",
+			scenario: "basic auth: non-existing GOTENBERG_API_BASIC_AUTH_USERNAME environment variable",
 			ctx: func() *gotenberg.Context {
 				fs := new(Api).Descriptor().FlagSet
-				err := fs.Parse([]string{"--api-port-from-env=PORT"})
+				err := fs.Parse([]string{"--api-enable-basic-auth=true"})
+				if err != nil {
+					t.Fatalf("expected no error but got: %v", err)
+				}
+
+				return gotenberg.NewContext(
+					gotenberg.ParsedFlags{
+						FlagSet: fs,
+					},
+					nil,
+				)
+			}(),
+			expectError: true,
+		},
+		{
+			scenario: "basic auth: non-existing GOTENBERG_API_BASIC_AUTH_PASSWORD environment variable",
+			ctx: func() *gotenberg.Context {
+				fs := new(Api).Descriptor().FlagSet
+				err := fs.Parse([]string{"--api-enable-basic-auth=true"})
 				if err != nil {
 					t.Fatalf("expected no error but got: %v", err)
 				}
@@ -74,7 +92,7 @@ func TestApi_Provision(t *testing.T) {
 				)
 			}(),
 			setEnv: func() {
-				err := os.Setenv("PORT", "")
+				err := os.Setenv("GOTENBERG_API_BASIC_AUTH_USERNAME", "foo")
 				if err != nil {
 					t.Fatalf("expected no error but got: %v", err)
 				}
@@ -361,7 +379,7 @@ func TestApi_Provision(t *testing.T) {
 				}
 
 				fs := new(Api).Descriptor().FlagSet
-				err := fs.Parse([]string{"--api-port-from-env=PORT"})
+				err := fs.Parse([]string{"--api-port-from-env=PORT", "--api-enable-basic-auth=true"})
 				if err != nil {
 					t.Fatalf("expected no error but got: %v", err)
 				}
@@ -383,6 +401,14 @@ func TestApi_Provision(t *testing.T) {
 				if err != nil {
 					t.Fatalf("expected no error but got: %v", err)
 				}
+				err = os.Setenv("GOTENBERG_API_BASIC_AUTH_USERNAME", "foo")
+				if err != nil {
+					t.Fatalf("expected no error but got: %v", err)
+				}
+				err = os.Setenv("GOTENBERG_API_BASIC_AUTH_PASSWORD", "bar")
+				if err != nil {
+					t.Fatalf("expected no error but got: %v", err)
+				}
 			},
 			expectPort: 1337,
 			expectMiddlewares: []Middleware{
@@ -671,6 +697,8 @@ func TestApi_Start(t *testing.T) {
 			mod.port = 3000
 			mod.startTimeout = time.Duration(30) * time.Second
 			mod.rootPath = "/"
+			mod.basicAuthUsername = "foo"
+			mod.basicAuthPassword = "bar"
 			mod.disableHealthCheckLogging = true
 			mod.routes = []Route{
 				{
@@ -755,6 +783,7 @@ func TestApi_Start(t *testing.T) {
 			// health request.
 			recorder := httptest.NewRecorder()
 			healthRequest := httptest.NewRequest(http.MethodGet, "/health", nil)
+			healthRequest.SetBasicAuth(mod.basicAuthUsername, mod.basicAuthPassword)
 
 			mod.srv.ServeHTTP(recorder, healthRequest)
 			if recorder.Code != http.StatusOK {
@@ -791,6 +820,7 @@ func TestApi_Start(t *testing.T) {
 
 				req := httptest.NewRequest(http.MethodPost, url, body)
 				req.Header.Set(echo.HeaderContentType, writer.FormDataContentType())
+				req.SetBasicAuth(mod.basicAuthUsername, mod.basicAuthPassword)
 
 				return req
 			}

pkg/modules/api/middlewares.go

@@ -2,6 +2,7 @@ package api
 
 import (
 	"context"
+	"crypto/subtle"
 	"errors"
 	"fmt"
 	"net/http"
@@ -10,6 +11,7 @@ import (
 
 	"github.com/google/uuid"
 	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
 	"go.uber.org/zap"
 
 	"github.com/gotenberg/gotenberg/v8/pkg/gotenberg"
@@ -112,7 +114,6 @@ func rootPathMiddleware(rootPath string) echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
 			c.Set("rootPath", rootPath)
-
 			// Call the next middleware in the chain.
 			return next(c)
 		}
@@ -217,6 +218,17 @@ func loggerMiddleware(logger *zap.Logger, disableLoggingForPaths []string) echo.
 	}
 }
 
+// basicAuthMiddleware manages basic authentication.
+func basicAuthMiddleware(username, password string) echo.MiddlewareFunc {
+	return middleware.BasicAuth(func(u string, p string, e echo.Context) (bool, error) {
+		if subtle.ConstantTimeCompare([]byte(u), []byte(username)) == 1 &&
+			subtle.ConstantTimeCompare([]byte(p), []byte(password)) == 1 {
+			return true, nil
+		}
+		return false, nil
+	})
+}
+
 // contextMiddleware, a middleware for "multipart/form-data" requests, sets the
 // [Context] and related context.CancelFunc in the [echo.Context] under
 // "context" and "cancel". If the process is synchronous, it also handles the

pkg/modules/api/middlewares_test.go

@@ -236,6 +236,56 @@ func TestTraceMiddleware(t *testing.T) {
 	}
 }
 
+func TestBasicAuthMiddleware(t *testing.T) {
+	for _, tc := range []struct {
+		scenario    string
+		request     *http.Request
+		username    string
+		password    string
+		expectError bool
+	}{
+		{
+			scenario: "invalid basic auth",
+			request: func() *http.Request {
+				req := httptest.NewRequest(http.MethodGet, "/", nil)
+				req.SetBasicAuth("invalid", "invalid")
+				return req
+			}(),
+			username:    "foo",
+			password:    "bar",
+			expectError: true,
+		},
+		{
+			scenario: "valid basic auth",
+			request: func() *http.Request {
+				req := httptest.NewRequest(http.MethodGet, "/", nil)
+				req.SetBasicAuth("foo", "bar")
+				return req
+			}(),
+			username:    "foo",
+			password:    "bar",
+			expectError: false,
+		},
+	} {
+		t.Run(tc.scenario, func(t *testing.T) {
+			recorder := httptest.NewRecorder()
+			srv := echo.New()
+			srv.HideBanner = true
+			srv.HidePort = true
+			c := srv.NewContext(tc.request, recorder)
+			err := basicAuthMiddleware(tc.username, tc.password)(func(c echo.Context) error {
+				return nil
+			})(c)
+			if !tc.expectError && err != nil {
+				t.Fatalf("expected no error but got: %v", err)
+			}
+			if tc.expectError && err == nil {
+				t.Fatal("expected error but got none")
+			}
+		})
+	}
+}
+
 func TestLoggerMiddleware(t *testing.T) {
 	for i, tc := range []struct {
 		request     *http.Request