webhook: switch to contextual logger (#1295)

Use k8s contextual logger instead of own. Comparing to other parts
of the operator webhook is a bit special since it serves own
endpoints and has context independent from controllers.

Include more info (operation), just to get more details. Do not add
kind since it's clear from "resource" field.

Since controller-framework adds "admission" to the name, use own
LogConstructor with own base logger for the framework's
DefaultLogConstructor.

Add name locally to distinguish from framework's messages.

Add Name field to the structures to avoid copying string literal for
both WithName() and WithValues().

The output changes and it looks like

```
{"level":"info","ts":"2024-10-11T05:17:20Z","logger":"ValidatingWebhook","msg":"Validation request","object":{"name":"default-dsci"},"namespace":"","name":"default-dsci","resource":{"group":"dscinitialization.opendatahub.io","version":"v1","resource":"dscinitializations"},"user":"kube:admin","requestID":"e5bf3768-6faa-4e14-9004-e54ee84ad8b7","webhook":"ValidatingWebhook","operation":"CREATE"}
```

or for the defaulter:

```
{"level":"info","ts":"2024-10-11T04:50:48Z","logger":"DefaultingWebhook","msg":"Defaulting DSC","object":{"name":"default-dsc"},"namespace":"","name":"default-dsc","resource":{"group":"datasciencecluster.opendatahub.io","version":"v1","resource":"datascienceclusters"},"user":"kube:admin","requestID":"c9213ff3-80ee-40c0-9f15-12188dece68e","webhook":"DefaultingWebhook"}
```

(the messages are not from the current codebase, was added for demo only)

Signed-off-by: Yauheni Kaliuta <ykaliuta@redhat.com>

controllers/webhook/webhook.go

@@ -23,13 +23,15 @@ import (
 	"fmt"
 	"net/http"
 
+	"github.com/go-logr/logr"
 	operatorv1 "github.com/openshift/api/operator/v1"
 	admissionv1 "k8s.io/api/admission/v1"
 	"k8s.io/apimachinery/pkg/apis/meta/v1/unstructured"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 	ctrl "sigs.k8s.io/controller-runtime"
 	"sigs.k8s.io/controller-runtime/pkg/client"
+	logf "sigs.k8s.io/controller-runtime/pkg/log"
 	"sigs.k8s.io/controller-runtime/pkg/webhook"
 	"sigs.k8s.io/controller-runtime/pkg/webhook/admission"
 
@@ -38,29 +40,44 @@ import (
 	"github.com/opendatahub-io/opendatahub-operator/v2/pkg/cluster/gvk"
 )
 
-var log = ctrl.Log.WithName("odh-controller-webhook")
-
 //+kubebuilder:webhook:path=/validate-opendatahub-io-v1,mutating=false,failurePolicy=fail,sideEffects=None,groups=datasciencecluster.opendatahub.io;dscinitialization.opendatahub.io,resources=datascienceclusters;dscinitializations,verbs=create;delete,versions=v1,name=operator.opendatahub.io,admissionReviewVersions=v1
 //nolint:lll
 
+// TODO: Get rid of platform in name, rename to ValidatingWebhook.
 type OpenDataHubValidatingWebhook struct {
 	Client  client.Client
 	Decoder *admission.Decoder
+	Name    string
 }
 
 func Init(mgr ctrl.Manager) {
 	(&OpenDataHubValidatingWebhook{
 		Client:  mgr.GetClient(),
 		Decoder: admission.NewDecoder(mgr.GetScheme()),
+		Name:    "ValidatingWebhook",
+	}).SetupWithManager(mgr)
+
+	(&DSCDefaulter{
+		Name: "DefaultingWebhook",
 	}).SetupWithManager(mgr)
+}
 
-	(&DSCDefaulter{}).SetupWithManager(mgr)
+// newLogConstructor creates a new logger constructor for a webhook.
+// It is based on the root controller-runtime logger witch is set in main.go
+// The purpose of it is to remove "admission" from the log name.
+func newLogConstructor(name string) func(logr.Logger, *admission.Request) logr.Logger {
+	return func(_ logr.Logger, req *admission.Request) logr.Logger {
+		base := ctrl.Log
+		l := admission.DefaultLogConstructor(base, req)
+		return l.WithValues("webhook", name)
+	}
 }
 
 func (w *OpenDataHubValidatingWebhook) SetupWithManager(mgr ctrl.Manager) {
 	hookServer := mgr.GetWebhookServer()
 	odhWebhook := &webhook.Admission{
-		Handler: w,
+		Handler:        w,
+		LogConstructor: newLogConstructor(w.Name),
 	}
 	hookServer.Register("/validate-opendatahub-io-v1", odhWebhook)
 }
@@ -90,6 +107,8 @@ func denyCountGtZero(ctx context.Context, cli client.Client, gvk schema.GroupVer
 }
 
 func (w *OpenDataHubValidatingWebhook) checkDupCreation(ctx context.Context, req admission.Request) admission.Response {
+	log := logf.FromContext(ctx)
+
 	switch req.Kind.Kind {
 	case "DataScienceCluster", "DSCInitialization":
 	default:
@@ -119,6 +138,9 @@ func (w *OpenDataHubValidatingWebhook) checkDeletion(ctx context.Context, req ad
 }
 
 func (w *OpenDataHubValidatingWebhook) Handle(ctx context.Context, req admission.Request) admission.Response {
+	log := logf.FromContext(ctx).WithName(w.Name).WithValues("operation", req.Operation)
+	ctx = logf.IntoContext(ctx, log)
+
 	var resp admission.Response
 	resp.Allowed = true // initialize Allowed to be true in case Operation falls into "default" case
 
@@ -141,19 +163,23 @@ func (w *OpenDataHubValidatingWebhook) Handle(ctx context.Context, req admission
 //+kubebuilder:webhook:path=/mutate-opendatahub-io-v1,mutating=true,failurePolicy=fail,sideEffects=None,groups=datasciencecluster.opendatahub.io,resources=datascienceclusters,verbs=create;update,versions=v1,name=mutate.operator.opendatahub.io,admissionReviewVersions=v1
 //nolint:lll
 
-type DSCDefaulter struct{}
+type DSCDefaulter struct {
+	Name string
+}
 
 // just assert that DSCDefaulter implements webhook.CustomDefaulter.
 var _ webhook.CustomDefaulter = &DSCDefaulter{}
 
 func (m *DSCDefaulter) SetupWithManager(mgr ctrl.Manager) {
 	mutateWebhook := admission.WithCustomDefaulter(mgr.GetScheme(), &dscv1.DataScienceCluster{}, m)
+	mutateWebhook.LogConstructor = newLogConstructor(m.Name)
 	mgr.GetWebhookServer().Register("/mutate-opendatahub-io-v1", mutateWebhook)
 }
 
 // Implement admission.CustomDefaulter interface.
 // It currently only sets defaults for modelregiestry in datascienceclusters.
 func (m *DSCDefaulter) Default(_ context.Context, obj runtime.Object) error {
+	// TODO: add debug logging, log := logf.FromContext(ctx).WithName(m.Name)
 	dsc, isDSC := obj.(*dscv1.DataScienceCluster)
 	if !isDSC {
 		return fmt.Errorf("expected DataScienceCluster but got a different type: %T", obj)