Add basic auth for metrics endpoint

config.yml.sample

@@ -13,9 +13,6 @@ service:
   rootpath: <rootpath>
   # The max number of items which can be returned per page
   maxitemsperpage: 50
-  # If set to true, enables a /metrics endpoint for prometheus to collect metrics about the system
-  # You'll need to use redis for this in order to enable common metrics over multiple nodes
-  enablemetrics: false
   # Enable the caldav endpoint, see the docs for more details
   enablecaldav: true
   # Set the motd message, available from the /info endpoint
@@ -283,3 +280,12 @@ auth:
         clientid:
         # The client secret used to authenticate Vikunja at the OpenID Connect provider.
         clientsecret:
+
+# Prometheus metrics endpoint
+metrics:
+  # If set to true, enables a /metrics endpoint for prometheus to collect metrics about Vikunja.
+  enabled: false
+  # If set to a non-empty value the /metrics endpoint will require this as a username via basic auth in combination with the password below.
+  username:
+  # If set to a non-empty value the /metrics endpoint will require this as a password via basic auth in combination with the username below.
+  password:

docs/content/doc/setup/config.md

@@ -100,13 +100,6 @@ The max number of items which can be returned per page
 
 Default: `50`
 
-### enablemetrics
-
-If set to true, enables a /metrics endpoint for prometheus to collect metrics about the system
-You'll need to use redis for this in order to enable common metrics over multiple nodes
-
-Default: `false`
-
 ### enablecaldav
 
 Enable the caldav endpoint, see the docs for more details
@@ -623,3 +616,29 @@ Take a look at the [default config file](https://kolaente.dev/vikunja/api/src/br
 
 Default: `<empty>`
 
+---
+
+## metrics
+
+Prometheus metrics endpoint
+
+
+
+### enabled
+
+If set to true, enables a /metrics endpoint for prometheus to collect metrics about Vikunja.
+
+Default: `false`
+
+### username
+
+If set to a non-empty value the /metrics endpoint will require this as a username via basic auth in combination with the password below.
+
+Default: `<empty>`
+
+### password
+
+If set to a non-empty value the /metrics endpoint will require this as a password via basic auth in combination with the username below.
+
+Default: `<empty>`
+

pkg/config/config.go

@@ -42,6 +42,7 @@ const (
 	ServiceEnableCaldav    Key = `service.enablecaldav`
 	ServiceRootpath        Key = `service.rootpath`
 	ServiceMaxItemsPerPage Key = `service.maxitemsperpage`
+	// Deprecated. Use metrics.enabled
 	ServiceEnableMetrics         Key = `service.enablemetrics`
 	ServiceMotd                  Key = `service.motd`
 	ServiceEnableLinkSharing     Key = `service.enablelinksharing`
@@ -142,6 +143,10 @@ const (
 	BackgroundsUnsplashApplicationID Key = `backgrounds.providers.unsplash.applicationid`
 
 	KeyvalueType Key = `keyvalue.type`
+
+	MetricsEnabled  Key = `metrics.enabled`
+	MetricsUsername Key = `metrics.username`
+	MetricsPassword Key = `metrics.password`
 )
 
 // GetString returns a string config value
@@ -311,6 +316,8 @@ func InitDefaultConfig() {
 	BackgroundsUnsplashEnabled.setDefault(false)
 	// Key Value
 	KeyvalueType.setDefault("memory")
+	// Metrics
+	MetricsEnabled.setDefault(false)
 }
 
 // InitConfig initializes the config, sets defaults etc.
@@ -364,6 +371,11 @@ func InitConfig() {
 		MigrationMicrosoftTodoRedirectURL.Set(ServiceFrontendurl.GetString() + "migrate/microsoft-todo")
 	}
 
+	if ServiceEnableMetrics.GetBool() {
+		log.Println("WARNING: service.enablemetrics is deprecated and will be removed in a future release. Please use metrics.enable.")
+		MetricsEnabled.Set(true)
+	}
+
 	log.Printf("Using config file: %s", viper.ConfigFileUsed())
 }
 

pkg/routes/metrics.go

@@ -17,6 +17,8 @@
 package routes
 
 import (
+	"crypto/subtle"
+
 	"code.vikunja.io/api/pkg/config"
 	"code.vikunja.io/api/pkg/log"
 	"code.vikunja.io/api/pkg/metrics"
@@ -24,11 +26,12 @@ import (
 	auth2 "code.vikunja.io/api/pkg/modules/auth"
 	"code.vikunja.io/api/pkg/user"
 	"github.com/labstack/echo/v4"
+	"github.com/labstack/echo/v4/middleware"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 )
 
 func setupMetrics(a *echo.Group) {
-	if !config.ServiceEnableMetrics.GetBool() {
+	if !config.MetricsEnabled.GetBool() {
 		return
 	}
 
@@ -71,11 +74,23 @@ func setupMetrics(a *echo.Group) {
 		}
 	}
 
-	a.GET("/metrics", echo.WrapHandler(promhttp.HandlerFor(metrics.GetRegistry(), promhttp.HandlerOpts{})))
+	r := a.Group("/metrics")
+
+	if config.MetricsUsername.GetString() != "" && config.MetricsPassword.GetString() != "" {
+		r.Use(middleware.BasicAuth(func(username, password string, c echo.Context) (bool, error) {
+			if subtle.ConstantTimeCompare([]byte(username), []byte(config.MetricsUsername.GetString())) == 1 &&
+				subtle.ConstantTimeCompare([]byte(password), []byte(config.MetricsPassword.GetString())) == 1 {
+				return true, nil
+			}
+			return false, nil
+		}))
+	}
+
+	r.GET("", echo.WrapHandler(promhttp.HandlerFor(metrics.GetRegistry(), promhttp.HandlerOpts{})))
 }
 
 func setupMetricsMiddleware(a *echo.Group) {
-	if !config.ServiceEnableMetrics.GetBool() {
+	if !config.MetricsEnabled.GetBool() {
 		return
 	}