fix: address nil pointer when controller runs with sts and replicas >…

… 1 (argoproj#15770)

* fix: address nil pointer when controller runs with sts and replicas > 1

Signed-off-by: Leonardo Luz Almeida <leonardo_almeida@intuit.com>

* fix: lint

Signed-off-by: Leonardo Luz Almeida <leonardo_almeida@intuit.com>

* fix: better handle errors

Signed-off-by: Leonardo Luz Almeida <leonardo_almeida@intuit.com>

---------

Signed-off-by: Leonardo Luz Almeida <leonardo_almeida@intuit.com>

util/db/db.go

@@ -6,13 +6,15 @@ import (
 	"strings"
 
 	v1 "k8s.io/api/core/v1"
+	kubeerrors "k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/client-go/kubernetes"
 
 	"github.com/argoproj/argo-cd/v2/common"
 	appv1 "github.com/argoproj/argo-cd/v2/pkg/apis/application/v1alpha1"
 	"github.com/argoproj/argo-cd/v2/util/env"
 	"github.com/argoproj/argo-cd/v2/util/settings"
+	log "github.com/sirupsen/logrus"
 )
 
 // SecretMaperValidation determine whether the secret should be transformed(i.e. trailing CRLF characters trimmed)
@@ -153,8 +155,13 @@ func (db *db) GetApplicationControllerReplicas() int {
 	// get the replicas from application controller deployment, if the application controller deployment does not exist, check for environment variable
 	applicationControllerName := env.StringFromEnv(common.EnvAppControllerName, common.DefaultApplicationControllerName)
 	appControllerDeployment, err := db.kubeclientset.AppsV1().Deployments(db.settingsMgr.GetNamespace()).Get(context.Background(), applicationControllerName, metav1.GetOptions{})
-
-	if err == nil && appControllerDeployment.Spec.Replicas != nil {
+	if err != nil {
+		appControllerDeployment = nil
+		if !kubeerrors.IsNotFound(err) {
+			log.Warnf("error retrieveing Argo CD controller deployment: %s", err)
+		}
+	}
+	if appControllerDeployment != nil && appControllerDeployment.Spec.Replicas != nil {
 		return int(*appControllerDeployment.Spec.Replicas)
 	}
 	return env.ParseNumFromEnv(common.EnvControllerReplicas, 0, 0, math.MaxInt32)