feat: Add Deployments to ClusterResources (#992)

* feat: add support for Deployments

* Update crates/stackable-operator/CHANGELOG.md

Co-authored-by: Sebastian Bernauer <[email protected]>

---------

Co-authored-by: Sebastian Bernauer <[email protected]>

Author: razvan

Diff for: crates/stackable-operator/CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 ## [Unreleased]
 
+### Added
+
+- Add Deployments to `ClusterResource`s ([#992]).
+
+[#992]: https://github.com/stackabletech/operator-rs/pull/992
+
 ## [0.87.5] - 2025-03-19
 
 ### Fixed

Diff for: crates/stackable-operator/src/cluster_resources.rs

@@ -7,7 +7,9 @@ use std::{
 
 use k8s_openapi::{
     api::{
-        apps::v1::{DaemonSet, DaemonSetSpec, StatefulSet, StatefulSetSpec},
+        apps::v1::{
+            DaemonSet, DaemonSetSpec, Deployment, DeploymentSpec, StatefulSet, StatefulSetSpec,
+        },
         batch::v1::Job,
         core::v1::{
             ConfigMap, ObjectReference, PodSpec, PodTemplateSpec, Secret, Service, ServiceAccount,
@@ -279,6 +281,29 @@ impl ClusterResource for DaemonSet {
     }
 }
 
+impl ClusterResource for Deployment {
+    fn maybe_mutate(self, strategy: &ClusterResourceApplyStrategy) -> Self {
+        match strategy {
+            ClusterResourceApplyStrategy::ClusterStopped => Deployment {
+                spec: Some(DeploymentSpec {
+                    replicas: Some(0),
+                    ..self.spec.unwrap_or_default()
+                }),
+                ..self
+            },
+            ClusterResourceApplyStrategy::Default
+            | ClusterResourceApplyStrategy::ReconciliationPaused
+            | ClusterResourceApplyStrategy::NoApply => self,
+        }
+    }
+
+    fn pod_spec(&self) -> Option<&PodSpec> {
+        self.spec
+            .as_ref()
+            .and_then(|spec| spec.template.spec.as_ref())
+    }
+}
+
 /// A structure containing the cluster resources.
 ///
 /// Cluster resources can be added and orphaned resources are deleted. A cluster resource becomes