feat: zap log level as environment variable (#35)

cmd/main.go

@@ -20,14 +20,16 @@ import (
 
 	// Import all Kubernetes client auth plugins (e.g. Azure, GCP, OIDC, etc.)
 	// to ensure that exec-entrypoint and run can make use of them.
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
 	_ "k8s.io/client-go/plugin/pkg/client/auth"
 
 	"k8s.io/apimachinery/pkg/runtime"
 	utilruntime "k8s.io/apimachinery/pkg/util/runtime"
 	clientgoscheme "k8s.io/client-go/kubernetes/scheme"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/healthz"
-	"sigs.k8s.io/controller-runtime/pkg/log/zap"
+	ctrlZap "sigs.k8s.io/controller-runtime/pkg/log/zap"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 
 	autoscalingv1alpha1 "github.com/google/kube-startup-cpu-boost/api/v1alpha1"
@@ -59,10 +61,11 @@ func main() {
 		setupLog.Error(err, "unable to load configuration")
 		os.Exit(1)
 	}
-	opts := zap.Options{
+	ctrlZapOpts := ctrlZap.Options{
 		Development: true,
+		Level:       zap.NewAtomicLevelAt(zapcore.Level(cfg.ZapLogLevel)),
 	}
-	ctrl.SetLogger(zap.New(zap.UseFlagOptions(&opts)))
+	ctrl.SetLogger(ctrlZap.New(ctrlZap.UseFlagOptions(&ctrlZapOpts)))
 	tlsOpts := []func(*tls.Config){}
 
 	webhookServer := webhook.NewServer(webhook.Options{

config/default/manager_config_patch.yaml

@@ -8,13 +8,13 @@ spec:
     spec:
       containers:
       - name: manager
-        args:
-        - --zap-log-level=5
         env:
         - name: POD_NAMESPACE
           valueFrom:
             fieldRef:
               fieldPath: metadata.namespace
+        - name: ZAP_LOG_LEVEL
+          value: "-5"
         - name: "LEADER_ELECTION"
           value: "true"
         - name: METRICS_PROBE_BIND_ADDR

go.mod

@@ -22,7 +22,7 @@ require (
 	github.com/emicklei/go-restful/v3 v3.11.3 // indirect
 	github.com/evanphx/json-patch/v5 v5.9.0 // indirect
 	github.com/fsnotify/fsnotify v1.7.0 // indirect
-	github.com/go-logr/zapr v1.3.0 // indirect
+	github.com/go-logr/zapr v1.3.0
 	github.com/go-openapi/jsonpointer v0.21.0 // indirect
 	github.com/go-openapi/jsonreference v0.21.0 // indirect
 	github.com/go-openapi/swag v0.23.0 // indirect
@@ -51,7 +51,7 @@ require (
 	go.uber.org/atomic v1.11.0 // indirect
 	go.uber.org/mock v0.4.0
 	go.uber.org/multierr v1.11.0 // indirect
-	go.uber.org/zap v1.27.0 // indirect
+	go.uber.org/zap v1.27.0
 	golang.org/x/exp v0.0.0-20240222234643-814bf88cf225 // indirect
 	golang.org/x/net v0.22.0 // indirect
 	golang.org/x/oauth2 v0.18.0 // indirect

internal/config/config.go

@@ -22,6 +22,7 @@ const (
 	MetricsProbeBindAddrDefault = ":8080"
 	HealthProbeBindAddrDefault  = ":8081"
 	SecureMetricsDefault        = false
+	ZapLogLevelDefault          = 0 // zapcore.InfoLevel
 )
 
 // ConfigProvider provides the Kube Startup CPU Boost configuration
@@ -45,6 +46,8 @@ type Config struct {
 	HealthProbeBindAddr string
 	// SecureMetrics determines if the metrics endpoint is served securely
 	SecureMetrics bool
+	// ZapLogLevel determines the log level for the ZAP logger
+	ZapLogLevel int
 }
 
 // LoadDefaults loads the default configuration values
@@ -55,4 +58,5 @@ func (c *Config) LoadDefaults() {
 	c.MetricsProbeBindAddr = MetricsProbeBindAddrDefault
 	c.HealthProbeBindAddr = HealthProbeBindAddrDefault
 	c.SecureMetrics = SecureMetricsDefault
+	c.ZapLogLevel = ZapLogLevelDefault
 }

internal/config/config_test.go

@@ -47,5 +47,8 @@ var _ = Describe("Config", func() {
 		It("has valid secure metrics", func() {
 			Expect(cfg.SecureMetrics).To(Equal(config.SecureMetricsDefault))
 		})
+		It("has valid ZAP log level", func() {
+			Expect(cfg.ZapLogLevel).To(Equal(config.ZapLogLevelDefault))
+		})
 	})
 })

internal/config/env_provider.go

@@ -27,6 +27,7 @@ const (
 	MetricsProbeBindAddrEnvVar = "METRICS_PROBE_BIND_ADDR"
 	HealthProbeBindAddrEnvVar  = "HEALTH_PROBE_BIND_ADDR"
 	SecureMetricsEnvVar        = "SECURE_METRICS"
+	ZapLogLevelEnvVar          = "ZAP_LOG_LEVEL"
 )
 
 type LookupEnvFunc func(key string) (string, bool)
@@ -76,6 +77,20 @@ func (p *EnvConfigProvider) LoadConfig() (*Config, error) {
 			errs = append(errs, fmt.Errorf("%s value is not a bool: %s", SecureMetricsEnvVar, err))
 		}
 	}
+	if v, ok := p.lookupFunc(MgrCheckIntervalSecEnvVar); ok {
+		intVal, err := strconv.Atoi(v)
+		config.MgrCheckIntervalSec = intVal
+		if err != nil {
+			errs = append(errs, fmt.Errorf("%s value is not an int: %s", MgrCheckIntervalSecEnvVar, err))
+		}
+	}
+	if v, ok := p.lookupFunc(ZapLogLevelEnvVar); ok {
+		intVal, err := strconv.Atoi(v)
+		config.ZapLogLevel = intVal
+		if err != nil {
+			errs = append(errs, fmt.Errorf("%s value is not an int: %s", ZapLogLevelEnvVar, err))
+		}
+	}
 	var err error
 	if len(errs) > 0 {
 		err = errors.Join(errs...)

internal/config/env_provider_test.go

@@ -105,5 +105,15 @@ var _ = Describe("EnvProvider", func() {
 				Expect(cfg.SecureMetrics).To(BeTrue())
 			})
 		})
+		When("zap log level variable is set", func() {
+			var logLevel int
+			BeforeEach(func() {
+				logLevel = -5
+				lookupFuncMap[config.ZapLogLevelEnvVar] = fmt.Sprintf("%d", logLevel)
+			})
+			It("has valid check manager interval", func() {
+				Expect(cfg.ZapLogLevel).To(Equal(logLevel))
+			})
+		})
 	})
 })