Replace internal logger with uber-go/zap

Eliminates singleton logger pattern in favor of per-component zap
instances. Replaces slog-based logging interface with direct zap
calls throughout the codebase.

* Remove global logger singleton and wrapper functions
* Replace slog with uber-go/zap SugaredLogger
* Pass logger instances to all components and functions
* Maintain structured/unstructured log switching via UNSTRUCTURED_LOGS
* Preserve debug flag integration for log level control
* Use go-logr/zapr for NewLogr() Kubernetes logr.Logger compatibility

Signed-off-by: Varun Rajput <[email protected]>

Author: rvarun11

cmd/regup/app/root.go

@@ -3,8 +3,12 @@ package app
 
 import (
 	"github.com/spf13/cobra"
+
+	log "github.com/stacklok/toolhive/pkg/logger"
 )
 
+var logger = log.NewLogger()
+
 var rootCmd = &cobra.Command{
 	Use:               "regup",
 	DisableAutoGenTag: true,

cmd/regup/app/update.go

@@ -15,7 +15,6 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/stacklok/toolhive/pkg/container/verifier"
-	"github.com/stacklok/toolhive/pkg/logger"
 	"github.com/stacklok/toolhive/pkg/registry"
 )
 
@@ -304,7 +303,7 @@ func verifyServerProvenance(name string, server *registry.ImageMetadata) error {
 	logger.Infof("Verifying provenance for server %s with image %s", name, server.Image)
 
 	// Create verifier
-	v, err := verifier.New(server)
+	v, err := verifier.New(server, logger)
 	if err != nil {
 		return fmt.Errorf("failed to create verifier: %w", err)
 	}

cmd/regup/app/update_test.go

@@ -9,14 +9,11 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"github.com/stacklok/toolhive/pkg/logger"
 	"github.com/stacklok/toolhive/pkg/registry"
 )
 
 //nolint:paralleltest // This test manages temporary directories and cannot run in parallel
 func TestUpdateCmdFunc(t *testing.T) {
-	// Initialize logger for tests
-	logger.Initialize()
 
 	tests := []struct {
 		name        string

cmd/regup/main.go

@@ -5,12 +5,11 @@ import (
 	"os"
 
 	"github.com/stacklok/toolhive/cmd/regup/app"
-	"github.com/stacklok/toolhive/pkg/logger"
+	log "github.com/stacklok/toolhive/pkg/logger"
 )
 
 func main() {
-	// Initialize the logger system
-	logger.Initialize()
+	logger := log.NewLogger()
 
 	if err := app.NewRootCmd().Execute(); err != nil {
 		logger.Errorf("%v", err)

cmd/thv-operator/controllers/mcpserver_controller.go

@@ -13,6 +13,7 @@ import (
 	"strings"
 	"time"
 
+	"go.uber.org/zap"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	rbacv1 "k8s.io/api/rbac/v1"
@@ -28,13 +29,13 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/log"
 
 	mcpv1alpha1 "github.com/stacklok/toolhive/cmd/thv-operator/api/v1alpha1"
-	"github.com/stacklok/toolhive/pkg/logger"
 )
 
 // MCPServerReconciler reconciles a MCPServer object
 type MCPServerReconciler struct {
 	client.Client
 	Scheme *runtime.Scheme
+	logger *zap.SugaredLogger
 }
 
 // defaultRBACRules are the default RBAC rules that the
@@ -222,7 +223,7 @@ func (r *MCPServerReconciler) Reconcile(ctx context.Context, req ctrl.Request) (
 	}
 
 	// Check if the deployment spec changed
-	if deploymentNeedsUpdate(deployment, mcpServer) {
+	if deploymentNeedsUpdate(deployment, mcpServer, r.logger) {
 		// Update the deployment
 		newDeployment := r.deploymentForMCPServer(mcpServer)
 		deployment.Spec = newDeployment.Spec
@@ -283,7 +284,7 @@ func (r *MCPServerReconciler) createRBACResource(
 ) error {
 	desired := createResource()
 	if err := controllerutil.SetControllerReference(mcpServer, desired, r.Scheme); err != nil {
-		logger.Error(fmt.Sprintf("Failed to set controller reference for %s", resourceType), err)
+		r.logger.Error(fmt.Sprintf("Failed to set controller reference for %s", resourceType), err)
 		return nil
 	}
 
@@ -309,7 +310,7 @@ func (r *MCPServerReconciler) updateRBACResourceIfNeeded(
 ) error {
 	desired := createResource()
 	if err := controllerutil.SetControllerReference(mcpServer, desired, r.Scheme); err != nil {
-		logger.Error(fmt.Sprintf("Failed to set controller reference for %s", resourceType), err)
+		r.logger.Error(fmt.Sprintf("Failed to set controller reference for %s", resourceType), err)
 		return nil
 	}
 
@@ -404,7 +405,7 @@ func (r *MCPServerReconciler) deploymentForMCPServer(m *mcpv1alpha1.MCPServer) *
 	if finalPodTemplateSpec != nil {
 		podTemplatePatch, err := json.Marshal(finalPodTemplateSpec)
 		if err != nil {
-			logger.Errorf("Failed to marshal pod template spec: %v", err)
+			r.logger.Errorf("Failed to marshal pod template spec: %v", err)
 		} else {
 			args = append(args, fmt.Sprintf("--k8s-pod-patch=%s", string(podTemplatePatch)))
 		}
@@ -619,7 +620,7 @@ func (r *MCPServerReconciler) deploymentForMCPServer(m *mcpv1alpha1.MCPServer) *
 
 	// Set MCPServer instance as the owner and controller
 	if err := controllerutil.SetControllerReference(m, dep, r.Scheme); err != nil {
-		logger.Error("Failed to set controller reference for Deployment", err)
+		r.logger.Error("Failed to set controller reference for Deployment", err)
 		return nil
 	}
 	return dep
@@ -676,7 +677,7 @@ func (r *MCPServerReconciler) serviceForMCPServer(m *mcpv1alpha1.MCPServer) *cor
 
 	// Set MCPServer instance as the owner and controller
 	if err := controllerutil.SetControllerReference(m, svc, r.Scheme); err != nil {
-		logger.Error("Failed to set controller reference for Service", err)
+		r.logger.Error("Failed to set controller reference for Service", err)
 		return nil
 	}
 	return svc
@@ -773,7 +774,7 @@ func (r *MCPServerReconciler) finalizeMCPServer(ctx context.Context, m *mcpv1alp
 // deploymentNeedsUpdate checks if the deployment needs to be updated
 //
 //nolint:gocyclo
-func deploymentNeedsUpdate(deployment *appsv1.Deployment, mcpServer *mcpv1alpha1.MCPServer) bool {
+func deploymentNeedsUpdate(deployment *appsv1.Deployment, mcpServer *mcpv1alpha1.MCPServer, logger *zap.SugaredLogger) bool {
 	// Check if the container args have changed
 	if len(deployment.Spec.Template.Spec.Containers) > 0 {
 		container := deployment.Spec.Template.Spec.Containers[0]
@@ -1198,13 +1199,13 @@ func (r *MCPServerReconciler) generateOIDCArgs(ctx context.Context, m *mcpv1alph
 }
 
 // generateKubernetesOIDCArgs generates OIDC args for Kubernetes service account token validation
-func (*MCPServerReconciler) generateKubernetesOIDCArgs(m *mcpv1alpha1.MCPServer) []string {
+func (r *MCPServerReconciler) generateKubernetesOIDCArgs(m *mcpv1alpha1.MCPServer) []string {
 	var args []string
 	config := m.Spec.OIDCConfig.Kubernetes
 
 	// Set defaults if config is nil
 	if config == nil {
-		logger.Infof("Kubernetes OIDCConfig is nil for MCPServer %s, using default configuration", m.Name)
+		r.logger.Infof("Kubernetes OIDCConfig is nil for MCPServer %s, using default configuration", m.Name)
 		defaultUseClusterAuth := true
 		config = &mcpv1alpha1.KubernetesOIDCConfig{
 			UseClusterAuth: &defaultUseClusterAuth, // Default to true
@@ -1272,7 +1273,7 @@ func (r *MCPServerReconciler) generateConfigMapOIDCArgs( // nolint:gocyclo
 		Namespace: m.Namespace,
 	}, configMap)
 	if err != nil {
-		logger.Errorf("Failed to get ConfigMap %s: %v", config.Name, err)
+		r.logger.Errorf("Failed to get ConfigMap %s: %v", config.Name, err)
 		return args
 	}
 

cmd/thv-operator/controllers/mcpserver_oidc_test.go

@@ -27,14 +27,9 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 
 	mcpv1alpha1 "github.com/stacklok/toolhive/cmd/thv-operator/api/v1alpha1"
-	"github.com/stacklok/toolhive/pkg/logger"
+	log "github.com/stacklok/toolhive/pkg/logger"
 )
 
-func init() {
-	// Initialize logger for tests
-	logger.Initialize()
-}
-
 func TestGenerateOIDCArgs(t *testing.T) {
 	t.Parallel()
 
@@ -230,6 +225,7 @@ func TestGenerateOIDCArgs(t *testing.T) {
 			reconciler := &MCPServerReconciler{
 				Client: fakeClient,
 				Scheme: scheme,
+				logger: log.NewLogger(),
 			}
 
 			ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
@@ -245,7 +241,9 @@ func TestGenerateOIDCArgs(t *testing.T) {
 func TestGenerateKubernetesOIDCArgs(t *testing.T) {
 	t.Parallel()
 
-	reconciler := &MCPServerReconciler{}
+	reconciler := &MCPServerReconciler{
+		logger: log.NewLogger(),
+	}
 
 	tests := []struct {
 		name         string
@@ -357,7 +355,9 @@ func TestGenerateKubernetesOIDCArgs(t *testing.T) {
 func TestGenerateInlineOIDCArgs(t *testing.T) {
 	t.Parallel()
 
-	reconciler := &MCPServerReconciler{}
+	reconciler := &MCPServerReconciler{
+		logger: log.NewLogger(),
+	}
 
 	tests := []struct {
 		name         string

cmd/thv-operator/controllers/mcpserver_resource_overrides_test.go

@@ -25,6 +25,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 
 	mcpv1alpha1 "github.com/stacklok/toolhive/cmd/thv-operator/api/v1alpha1"
+	log "github.com/stacklok/toolhive/pkg/logger"
 )
 
 func TestResourceOverrides(t *testing.T) {
@@ -263,6 +264,7 @@ func TestResourceOverrides(t *testing.T) {
 			r := &MCPServerReconciler{
 				Client: client,
 				Scheme: scheme,
+				logger: log.NewLogger(),
 			}
 
 			// Test deployment creation
@@ -366,6 +368,7 @@ func TestDeploymentNeedsUpdateServiceAccount(t *testing.T) {
 	r := &MCPServerReconciler{
 		Client: client,
 		Scheme: scheme,
+		logger: log.NewLogger(),
 	}
 
 	mcpServer := &mcpv1alpha1.MCPServer{
@@ -384,7 +387,7 @@ func TestDeploymentNeedsUpdateServiceAccount(t *testing.T) {
 	require.NotNil(t, deployment)
 
 	// Test with the current deployment - this should NOT need update
-	needsUpdate := deploymentNeedsUpdate(deployment, mcpServer)
+	needsUpdate := deploymentNeedsUpdate(deployment, mcpServer, r.logger)
 
 	// With the service account bug fixed, this should now return false
 	assert.False(t, needsUpdate, "deploymentNeedsUpdate should return false when deployment matches MCPServer spec")
@@ -400,6 +403,7 @@ func TestDeploymentNeedsUpdateProxyEnv(t *testing.T) {
 	r := &MCPServerReconciler{
 		Client: client,
 		Scheme: scheme,
+		logger: log.NewLogger(),
 	}
 
 	tests := []struct {
@@ -563,7 +567,7 @@ func TestDeploymentNeedsUpdateProxyEnv(t *testing.T) {
 			deployment.Spec.Template.Spec.Containers[0].Image = getToolhiveRunnerImage()
 
 			// Test if deployment needs update - should correlate with env change expectation
-			needsUpdate := deploymentNeedsUpdate(deployment, tt.mcpServer)
+			needsUpdate := deploymentNeedsUpdate(deployment, tt.mcpServer, r.logger)
 
 			if tt.expectEnvChange {
 				assert.True(t, needsUpdate, "Expected deployment update due to proxy env change")
@@ -588,6 +592,7 @@ func TestDeploymentNeedsUpdateToolsFilter(t *testing.T) {
 	r := &MCPServerReconciler{
 		Client: client,
 		Scheme: scheme,
+		logger: log.NewLogger(),
 	}
 
 	tests := []struct {
@@ -643,7 +648,7 @@ func TestDeploymentNeedsUpdateToolsFilter(t *testing.T) {
 
 			mcpServer.Spec.ToolsFilter = tt.newToolsFilter
 
-			needsUpdate := deploymentNeedsUpdate(deployment, mcpServer)
+			needsUpdate := deploymentNeedsUpdate(deployment, mcpServer, r.logger)
 			assert.Equal(t, tt.expectEnvChange, needsUpdate)
 		})
 	}

cmd/thv-operator/main.go

@@ -48,9 +48,6 @@ func main() {
 			"Enabling this will ensure there is only one active controller manager.")
 	flag.Parse()
 
-	// Initialize the structured logger
-	logger.Initialize()
-
 	// Set the controller-runtime logger to use our structured logger
 	ctrl.SetLogger(logger.NewLogr())
 

cmd/thv-proxyrunner/app/commands.go

@@ -4,10 +4,13 @@ package app
 import (
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
+	"go.uber.org/zap"
 
-	"github.com/stacklok/toolhive/pkg/logger"
+	log "github.com/stacklok/toolhive/pkg/logger"
 )
 
+var logger *zap.SugaredLogger = log.NewLogger()
+
 var rootCmd = &cobra.Command{
 	Use:               "thv-proxyrunner",
 	DisableAutoGenTag: true,
@@ -20,9 +23,6 @@ It is written in Go and has extensive test coverage—including input validation
 			logger.Errorf("Error displaying help: %v", err)
 		}
 	},
-	PersistentPreRun: func(_ *cobra.Command, _ []string) {
-		logger.Initialize()
-	},
 }
 
 // NewRootCmd creates a new root command for the ToolHive CLI.

cmd/thv-proxyrunner/app/run.go

@@ -8,7 +8,6 @@ import (
 	"github.com/spf13/cobra"
 
 	"github.com/stacklok/toolhive/pkg/container"
-	"github.com/stacklok/toolhive/pkg/logger"
 	"github.com/stacklok/toolhive/pkg/registry"
 	"github.com/stacklok/toolhive/pkg/runner"
 	"github.com/stacklok/toolhive/pkg/transport"
@@ -224,7 +223,7 @@ func runCmdFunc(cmd *cobra.Command, args []string) error {
 	finalOtelEndpoint, finalOtelSamplingRate, finalOtelEnvironmentVariables := "", 0.0, []string{}
 
 	// Create container runtime
-	rt, err := container.NewFactory().Create(ctx)
+	rt, err := container.NewFactory(logger).Create(ctx)
 	if err != nil {
 		return fmt.Errorf("failed to create container runtime: %v", err)
 	}
@@ -233,12 +232,12 @@ func runCmdFunc(cmd *cobra.Command, args []string) error {
 	// If we have called the CLI directly, we use the CLIEnvVarValidator.
 	// If we are running in detached mode, or the CLI is wrapped by the K8s operator,
 	// we use the DetachedEnvVarValidator.
-	envVarValidator := &runner.DetachedEnvVarValidator{}
+	envVarValidator := runner.NewDetachedEnvVarValidator(logger)
 
 	var imageMetadata *registry.ImageMetadata
 
 	// Initialize a new RunConfig with values from command-line flags
-	runConfig, err := runner.NewRunConfigBuilder().
+	runConfig, err := runner.NewRunConfigBuilder(logger).
 		WithRuntime(rt).
 		WithCmdArgs(cmdArgs).
 		WithName(runName).
@@ -266,7 +265,7 @@ func runCmdFunc(cmd *cobra.Command, args []string) error {
 		return fmt.Errorf("failed to create RunConfig: %v", err)
 	}
 
-	workloadManager, err := workloads.NewManagerFromRuntime(rt)
+	workloadManager, err := workloads.NewManagerFromRuntime(rt, logger)
 	if err != nil {
 		return fmt.Errorf("failed to create workload manager: %v", err)
 	}