feat: sidecar init stability, drop k8s < 1.29 support

.github/workflows/e2e.yml

@@ -36,7 +36,7 @@ jobs:
           docker load --input ${{ github.workspace }}/open-feature-operator-local.tar
 
       - name: Create k8s Kind Cluster
-        uses: helm/kind-action@a1b0e391336a6ee6713a0583f8c6240d70863de3 # v1.12.0
+        uses: helm/kind-action@ef37e7f390d99f746eb8b610417061a60e82a6cc # v1.14.0
         with:
           config: ./test/e2e/kind-cluster.yml
           cluster_name: open-feature-operator-test

.github/workflows/pr-checks.yml

@@ -103,7 +103,7 @@ jobs:
       - docker-local
     strategy:
       matrix:
-        kind_tag: [ v1.22.17, v1.23.17, v1.24.15, v1.25.11, v1.26.3, v1.27.3, v1.28.0 ]
+        kind_tag: [v1.29.14, v1.30.13, v1.31.14, v1.32.11, v1.33.7, v1.34.3, v1.35.1]
     with:
       kind_tag: ${{ matrix.kind_tag }}
     uses: ./.github/workflows/e2e.yml

internal/common/flagdinjector/flagdinjector.go

@@ -20,6 +20,7 @@ import (
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/util/intstr"
+	"k8s.io/utils/ptr"
 	"sigs.k8s.io/controller-runtime/pkg/client"
 )
 
@@ -85,7 +86,14 @@ func (fi *FlagdContainerInjector) InjectFlagd(
 		flagdContainer.Resources.Limits = flagSourceConfig.Resources.Limits
 	}
 
-	addFlagdContainer(podSpec, flagdContainer)
+	// Handle standalone Flagd deployment as well as sidecar injection.
+	if len(podSpec.Containers) == 0 {
+		addFlagdContainer(podSpec, flagdContainer)
+	} else {
+		flagdContainer.RestartPolicy = ptr.To(corev1.ContainerRestartPolicyAlways)
+
+		addFlagdSidecarContainer(podSpec, flagdContainer)
+	}
 
 	return nil
 }
@@ -472,6 +480,16 @@ func (fi *FlagdContainerInjector) createConfigMap(ctx context.Context, namespace
 	return fi.Client.Create(ctx, cm)
 }
 
+func addFlagdSidecarContainer(spec *corev1.PodSpec, flagdContainer corev1.Container) {
+	for idx, container := range spec.InitContainers {
+		if container.Name == flagdContainer.Name {
+			spec.InitContainers[idx] = flagdContainer
+			return
+		}
+	}
+	spec.InitContainers = append(spec.InitContainers, flagdContainer)
+}
+
 func addFlagdContainer(spec *corev1.PodSpec, flagdContainer corev1.Container) {
 	for idx, container := range spec.Containers {
 		if container.Name == flagdContainer.Name {