feat(logging): Allow configuring logging verbosity level (#872)

* introduces TwiN/logr library

* use new features of logr library

* minor tweaks and formatting

* Apply suggestions from code review

---------

Co-authored-by: TwiN <twin@linux.com>

README.md

@@ -216,6 +216,7 @@ If you want to test it locally, see [Docker](#docker).
 | Parameter                    | Description                                                                                                                          | Default                    |
 |:-----------------------------|:-------------------------------------------------------------------------------------------------------------------------------------|:---------------------------|
 | `debug`                      | Whether to enable debug logs.                                                                                                        | `false`                    |
+| `log-level`                  | Log level: DEBUG, INFO, WARN, ERROR.                                                                                                 | `INFO`                     |
 | `metrics`                    | Whether to expose metrics at `/metrics`.                                                                                             | `false`                    |
 | `storage`                    | [Storage configuration](#storage).                                                                                                   | `{}`                       |
 | `alerting`                   | [Alerting configuration](#alerting).                                                                                                 | `{}`                       |

config/config.go

@@ -22,6 +22,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/web"
 	"github.com/TwiN/gatus/v5/security"
 	"github.com/TwiN/gatus/v5/storage"
+	"github.com/TwiN/logr"
 	"gopkg.in/yaml.v3"
 )
 
@@ -54,6 +55,9 @@ type Config struct {
 	// Debug Whether to enable debug logs
 	Debug bool `yaml:"debug,omitempty"`
 
+	// LogLevel is one of DEBUG, INFO, WARN and ERROR. Defaults to INFO
+	LogLevel logr.Level `yaml:"log-level,omitempty"`
+
 	// Metrics Whether to expose metrics at /metrics
 	Metrics bool `yaml:"metrics,omitempty"`
 

go.mod

@@ -1,6 +1,6 @@
 module github.com/TwiN/gatus/v5
 
-go 1.22.2
+go 1.22.4
 
 require (
 	code.gitea.io/sdk/gitea v0.19.0
@@ -8,6 +8,7 @@ require (
 	github.com/TwiN/g8/v2 v2.0.0
 	github.com/TwiN/gocache/v2 v2.2.2
 	github.com/TwiN/health v1.6.0
+	github.com/TwiN/logr v0.2.1
 	github.com/TwiN/whois v1.1.9
 	github.com/aws/aws-sdk-go v1.54.10
 	github.com/coreos/go-oidc/v3 v3.11.0

go.sum

@@ -16,6 +16,8 @@ github.com/TwiN/gocache/v2 v2.2.2 h1:4HToPfDV8FSbaYO5kkbhLpEllUYse5rAf+hVU/mSsuI
 github.com/TwiN/gocache/v2 v2.2.2/go.mod h1:WfIuwd7GR82/7EfQqEtmLFC3a2vqaKbs4Pe6neB7Gyc=
 github.com/TwiN/health v1.6.0 h1:L2ks575JhRgQqWWOfKjw9B0ec172hx7GdToqkYUycQM=
 github.com/TwiN/health v1.6.0/go.mod h1:Z6TszwQPMvtSiVx1QMidVRgvVr4KZGfiwqcD7/Z+3iw=
+github.com/TwiN/logr v0.2.1 h1:kMhUmBBVlFxzqTvyHuNoYQ/uwqg8BW4y0AyZxI5JB3Q=
+github.com/TwiN/logr v0.2.1/go.mod h1:oldDOkRjFXjZqiMP0+ca5NAQHXTiJ02zHirsuBJJH6k=
 github.com/TwiN/whois v1.1.9 h1:m20+m1CXnrstie+tW2ZmAJkfcT9zgwpVRUFsKeMw+ng=
 github.com/TwiN/whois v1.1.9/go.mod h1:TjipCMpJRAJYKmtz/rXQBU6UGxMh6bk8SHazu7OMnQE=
 github.com/andybalholm/brotli v1.1.0 h1:eLKJA0d02Lf0mVpIDgYnqXcUn0GqVmEFny3VuID1U3M=

main.go

@@ -12,6 +12,7 @@ import (
 	"github.com/TwiN/gatus/v5/controller"
 	"github.com/TwiN/gatus/v5/storage/store"
 	"github.com/TwiN/gatus/v5/watchdog"
+	"github.com/TwiN/logr"
 )
 
 func main() {
@@ -23,6 +24,7 @@ func main() {
 	if err != nil {
 		panic(err)
 	}
+	configureLogging(cfg)
 	initializeStorage(cfg)
 	start(cfg)
 	// Wait for termination signal
@@ -57,6 +59,11 @@ func save() {
 	}
 }
 
+func configureLogging(cfg *config.Config) {
+	logr.SetThreshold(cfg.LogLevel)
+	logr.Infof("[main.configureLogging] Log Level is %s", logr.GetThreshold())
+}
+
 func loadConfiguration() (*config.Config, error) {
 	configPath := os.Getenv("GATUS_CONFIG_PATH")
 	// Backwards compatibility

watchdog/watchdog.go

@@ -13,6 +13,7 @@ import (
 	"github.com/TwiN/gatus/v5/config/maintenance"
 	"github.com/TwiN/gatus/v5/metrics"
 	"github.com/TwiN/gatus/v5/storage/store"
+	"github.com/TwiN/logr"
 )
 
 var (
@@ -31,15 +32,15 @@ func Monitor(cfg *config.Config) {
 		if endpoint.IsEnabled() {
 			// To prevent multiple requests from running at the same time, we'll wait for a little before each iteration
 			time.Sleep(777 * time.Millisecond)
-			go monitor(endpoint, cfg.Alerting, cfg.Maintenance, cfg.Connectivity, cfg.DisableMonitoringLock, cfg.Metrics, cfg.Debug, ctx)
+			go monitor(endpoint, cfg.Alerting, cfg.Maintenance, cfg.Connectivity, cfg.DisableMonitoringLock, cfg.Metrics, ctx)
 		}
 	}
 }
 
 // monitor a single endpoint in a loop
-func monitor(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, connectivityConfig *connectivity.Config, disableMonitoringLock, enabledMetrics, debug bool, ctx context.Context) {
+func monitor(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, connectivityConfig *connectivity.Config, disableMonitoringLock bool, enabledMetrics bool, ctx context.Context) {
 	// Run it immediately on start
-	execute(ep, alertingConfig, maintenanceConfig, connectivityConfig, disableMonitoringLock, enabledMetrics, debug)
+	execute(ep, alertingConfig, maintenanceConfig, connectivityConfig, disableMonitoringLock, enabledMetrics)
 	// Loop for the next executions
 	for {
 		select {
@@ -47,7 +48,7 @@ func monitor(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenance
 			log.Printf("[watchdog.monitor] Canceling current execution of group=%s; endpoint=%s", ep.Group, ep.Name)
 			return
 		case <-time.After(ep.Interval):
-			execute(ep, alertingConfig, maintenanceConfig, connectivityConfig, disableMonitoringLock, enabledMetrics, debug)
+			execute(ep, alertingConfig, maintenanceConfig, connectivityConfig, disableMonitoringLock, enabledMetrics)
 		}
 	}
 	// Just in case somebody wandered all the way to here and wonders, "what about ExternalEndpoints?"
@@ -55,7 +56,7 @@ func monitor(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenance
 	// periodically like they are for normal endpoints.
 }
 
-func execute(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, connectivityConfig *connectivity.Config, disableMonitoringLock, enabledMetrics, debug bool) {
+func execute(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenanceConfig *maintenance.Config, connectivityConfig *connectivity.Config, disableMonitoringLock bool, enabledMetrics bool) {
 	if !disableMonitoringLock {
 		// By placing the lock here, we prevent multiple endpoints from being monitored at the exact same time, which
 		// could cause performance issues and return inaccurate results
@@ -64,37 +65,33 @@ func execute(ep *endpoint.Endpoint, alertingConfig *alerting.Config, maintenance
 	}
 	// If there's a connectivity checker configured, check if Gatus has internet connectivity
 	if connectivityConfig != nil && connectivityConfig.Checker != nil && !connectivityConfig.Checker.IsConnected() {
-		log.Println("[watchdog.execute] No connectivity; skipping execution")
+		logr.Infof("[watchdog.execute] No connectivity; skipping execution")
 		return
 	}
-	if debug {
+	logr.Debugf("[watchdog.execute] Monitoring group=%s; endpoint=%s", ep.Group, ep.Name)
-		log.Printf("[watchdog.execute] Monitoring group=%s; endpoint=%s", ep.Group, ep.Name)
-	}
 	result := ep.EvaluateHealth()
 	if enabledMetrics {
 		metrics.PublishMetricsForEndpoint(ep, result)
 	}
 	UpdateEndpointStatuses(ep, result)
-	if debug && !result.Success {
+	if logr.GetThreshold() == logr.LevelDebug && !result.Success {
-		log.Printf("[watchdog.execute] Monitored group=%s; endpoint=%s; success=%v; errors=%d; duration=%s; body=%s", ep.Group, ep.Name, result.Success, len(result.Errors), result.Duration.Round(time.Millisecond), result.Body)
+		logr.Debugf("[watchdog.execute] Monitored group=%s; endpoint=%s; success=%v; errors=%d; duration=%s; body=%s", ep.Group, ep.Name, result.Success, len(result.Errors), result.Duration.Round(time.Millisecond), result.Body)
 	} else {
-		log.Printf("[watchdog.execute] Monitored group=%s; endpoint=%s; success=%v; errors=%d; duration=%s", ep.Group, ep.Name, result.Success, len(result.Errors), result.Duration.Round(time.Millisecond))
+		logr.Infof("[watchdog.execute] Monitored group=%s; endpoint=%s; success=%v; errors=%d; duration=%s", ep.Group, ep.Name, result.Success, len(result.Errors), result.Duration.Round(time.Millisecond))
 	}
 	if !maintenanceConfig.IsUnderMaintenance() {
 		// TODO: Consider moving this after the monitoring lock is unlocked? I mean, how much noise can a single alerting provider cause...
-		HandleAlerting(ep, result, alertingConfig, debug)
+		HandleAlerting(ep, result, alertingConfig, logr.GetThreshold() == logr.LevelDebug)
-	} else if debug {
+	} else {
-		log.Println("[watchdog.execute] Not handling alerting because currently in the maintenance window")
+		logr.Debugf("[watchdog.execute] Not handling alerting because currently in the maintenance window")
-	}
-	if debug {
-		log.Printf("[watchdog.execute] Waiting for interval=%s before monitoring group=%s endpoint=%s again", ep.Interval, ep.Group, ep.Name)
 	}
+	logr.Debugf("[watchdog.execute] Waiting for interval=%s before monitoring group=%s endpoint=%s again", ep.Interval, ep.Group, ep.Name)
 }
 
 // UpdateEndpointStatuses updates the slice of endpoint statuses
 func UpdateEndpointStatuses(ep *endpoint.Endpoint, result *endpoint.Result) {
 	if err := store.Get().Insert(ep, result); err != nil {
-		log.Println("[watchdog.UpdateEndpointStatuses] Failed to insert result in storage:", err.Error())
+		logr.Errorf("[watchdog.UpdateEndpointStatuses] Failed to insert result in storage:", err.Error())
 	}
 }