add release notes and add keyfile for all containers

Author: nammn

changelog/20250806_breaking_changing_container_setup_of_static_architecture.md

@@ -0,0 +1,8 @@
+---
+title: Changing container setup of static architecture
+kind: breaking
+date: 2025-08-06
+---
+
+This change fixes the current complex and difficult-to-maintain architecture for stateful set containers, which relies on an "agent matrix" to map operator and agent versions which led to a sheer amount of images.
+We solve this by shifting to a 3-container setup. This new design eliminates the need for the operator-version/agent-version matrix by adding one additional container containing all required binaries. This architecture maps to what we already do with the mongodb-database container.

controllers/operator/construct/appdb_construction.go

@@ -233,6 +233,12 @@ func CAConfigMapName(appDb om.AppDBSpec, log *zap.SugaredLogger) string {
 // and volumemounts for TLS.
 func tlsVolumes(appDb om.AppDBSpec, podVars *env.PodEnvVars, log *zap.SugaredLogger) podtemplatespec.Modification {
 	volumesToAdd, volumeMounts := getTLSVolumesAndVolumeMounts(appDb, podVars, log)
+
+	// Add agent API key volume mount if not using vault and monitoring is enabled
+	if !vault.IsVaultSecretBackend() && ShouldEnableMonitoring(podVars) {
+		volumeMounts = append(volumeMounts, statefulset.CreateVolumeMount(AgentAPIKeyVolumeName, AgentAPIKeySecretPath))
+	}
+
 	volumesFunc := func(spec *corev1.PodTemplateSpec) {
 		for _, v := range volumesToAdd {
 			podtemplatespec.WithVolume(v)(spec)

controllers/operator/construct/database_construction.go

@@ -494,6 +494,7 @@ func buildDatabaseStatefulSetConfigurationFunction(mdb databaseStatefulSetSource
 		shareProcessNs = func(sts *appsv1.StatefulSet) {
 			sts.Spec.Template.Spec.ShareProcessNamespace = ptr.To(true)
 		}
+		staticMods = append(staticMods, podtemplatespec.WithContainerByIndex(0, container.WithVolumeMounts(volumeMounts)))
 		staticMods = append(staticMods, podtemplatespec.WithContainerByIndex(1, container.WithVolumeMounts(volumeMounts)))
 		staticMods = append(staticMods, podtemplatespec.WithContainerByIndex(2, container.WithVolumeMounts(volumeMounts)))
 		databaseImage = opts.AgentImage