From 5e1a817a78b5ea6c16ab25e1c04c7cfd02f88fce Mon Sep 17 00:00:00 2001
From: Sebastian Widmer <sebastian.widmer@vshn.net>
Date: Thu, 4 Jan 2024 13:39:41 +0100
Subject: [PATCH] Remove token validity metric on delete of CRD (#16)

---
 controllers/emergencyaccount_controller.go    | 20 +++++++++++++++++
 .../emergencyaccount_controller_test.go       | 22 ++++++++++++++++++-
 controllers/metrics.go                        |  4 ++++
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/controllers/emergencyaccount_controller.go b/controllers/emergencyaccount_controller.go
index 392ab4d..8244724 100644
--- a/controllers/emergencyaccount_controller.go
+++ b/controllers/emergencyaccount_controller.go
@@ -23,6 +23,8 @@ import (
 	"github.com/appuio/emergency-credentials-controller/controllers/stores"
 )
 
+const EmergencyAccountFinalizer = "emergencyaccounts.cluster.appuio.io/finalizer"
+
 type Clock interface {
 	Now() time.Time
 }
@@ -60,6 +62,24 @@ func (r *EmergencyAccountReconciler) Reconcile(ctx context.Context, req ctrl.Req
 		return ctrl.Result{}, fmt.Errorf("unable to get EmergencyAccount resource: %w", err)
 	}
 
+	if instance.DeletionTimestamp != nil {
+		l.Info("EmergencyAccount resource is being deleted")
+		deleteVerifiedTokensValidUntil(instance.Name)
+		if controllerutil.RemoveFinalizer(instance, EmergencyAccountFinalizer) {
+			if err := r.Update(ctx, instance); err != nil {
+				return ctrl.Result{}, fmt.Errorf("unable to remove finalizer: %w", err)
+			}
+		}
+		return ctrl.Result{}, nil
+	}
+
+	if controllerutil.AddFinalizer(instance, EmergencyAccountFinalizer) {
+		if err := r.Update(ctx, instance); err != nil {
+			return ctrl.Result{}, fmt.Errorf("unable to add finalizer: %w", err)
+		}
+		return ctrl.Result{}, nil
+	}
+
 	sa, err := r.reconcileSA(ctx, instance)
 	if err != nil {
 		return ctrl.Result{}, fmt.Errorf("unable to reconcile ServiceAccount: %w", err)
diff --git a/controllers/emergencyaccount_controller_test.go b/controllers/emergencyaccount_controller_test.go
index 78b8d68..72913fa 100644
--- a/controllers/emergencyaccount_controller_test.go
+++ b/controllers/emergencyaccount_controller_test.go
@@ -7,6 +7,7 @@ import (
 	"time"
 
 	"github.com/go-logr/logr/testr"
+	"github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/stretchr/testify/require"
 	authenticationv1 "k8s.io/api/authentication/v1"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -16,6 +17,7 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/client/fake"
 	"sigs.k8s.io/controller-runtime/pkg/client/interceptor"
 	"sigs.k8s.io/controller-runtime/pkg/log"
+	"sigs.k8s.io/controller-runtime/pkg/metrics"
 	"sigs.k8s.io/controller-runtime/pkg/reconcile"
 
 	emcv1beta1 "github.com/appuio/emergency-credentials-controller/api/v1beta1"
@@ -55,11 +57,18 @@ func Test_EmergencyAccountReconciler_Reconcile(t *testing.T) {
 		Clock:  clock,
 	}
 
-	// Create token
+	// Create finalizer
 	_, err := subject.Reconcile(ctx, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(ea)})
 	require.NoError(t, err)
 	require.NoError(t, c.Get(ctx, client.ObjectKeyFromObject(ea), ea))
 	t.Logf("status %+v", ea.Status)
+	require.Len(t, ea.Finalizers, 1, "finalizer should be created")
+
+	// Create token
+	_, err = subject.Reconcile(ctx, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(ea)})
+	require.NoError(t, err)
+	require.NoError(t, c.Get(ctx, client.ObjectKeyFromObject(ea), ea))
+	t.Logf("status %+v", ea.Status)
 	require.Len(t, ea.Status.Tokens, 1, "token should be created")
 	require.WithinDuration(t, clock.Now(), ea.Status.LastTokenCreationTimestamp.Time, 0, "last token creation timestamp should be set")
 	lastTimestamp := ea.Status.LastTokenCreationTimestamp.Time
@@ -97,6 +106,17 @@ func Test_EmergencyAccountReconciler_Reconcile(t *testing.T) {
 	require.NoError(t, c.Get(ctx, client.ObjectKeyFromObject(ea), ea))
 	t.Logf("status %+v", ea.Status)
 	require.Len(t, ea.Status.Tokens, 3, "should add a new token")
+
+	// Finalizer should be removed and no metric left
+	require.NoError(t, c.Delete(ctx, ea))
+	deleted := &emcv1beta1.EmergencyAccount{}
+	_, err = subject.Reconcile(ctx, reconcile.Request{NamespacedName: client.ObjectKeyFromObject(ea)})
+	require.NoError(t, err)
+	require.Error(t, c.Get(ctx, client.ObjectKeyFromObject(ea), deleted))
+	require.Len(t, deleted.Finalizers, 0, "finalizer should be removed")
+	ml, err := testutil.GatherAndCount(metrics.Registry, MetricsNamespace+"_verified_tokens_valid_until_seconds")
+	require.NoError(t, err)
+	require.Equal(t, 0, ml, "metric should be removed")
 }
 
 type fakeClientControl struct {
diff --git a/controllers/metrics.go b/controllers/metrics.go
index be6956a..d8f9fa4 100644
--- a/controllers/metrics.go
+++ b/controllers/metrics.go
@@ -18,6 +18,10 @@ var (
 	)
 )
 
+func deleteVerifiedTokensValidUntil(emergencyAccount string) {
+	verifiedTokensValidUntil.Delete(prometheus.Labels{"emergency_account": emergencyAccount})
+}
+
 func init() {
 	metrics.Registry.MustRegister(verifiedTokensValidUntil)
 }