feat(overrides): add JSON patch for deployments

api/v1beta1/temporalcluster_types.go

@@ -174,7 +174,8 @@ type DeploymentOverride struct {
 	*ObjectMetaOverride `json:"metadata,omitempty"`
 	// Specification of the desired behavior of the Deployment.
 	// +optional
-	Spec *DeploymentOverrideSpec `json:"spec,omitempty"`
+	Spec      *DeploymentOverrideSpec `json:"spec,omitempty"`
+	JSONPatch *apiextensionsv1.JSON   `json:"jsonPatch,omitempty"`
 }
 
 // DeploymentOverrideSpec provides the ability to override a Deployment Spec.

config/crd/bases/temporal.io_temporalclusters.yaml

@@ -64,6 +64,8 @@ spec:
                         deployment:
                           description: Override configuration for the temporal service Deployment.
                           properties:
+                            jsonPatch:
+                              x-kubernetes-preserve-unknown-fields: true
                             metadata:
                               description: |-
                                 ObjectMetaOverride provides the ability to override an object metadata.
@@ -2910,6 +2912,8 @@ spec:
                             deployment:
                               description: Override configuration for the temporal service Deployment.
                               properties:
+                                jsonPatch:
+                                  x-kubernetes-preserve-unknown-fields: true
                                 metadata:
                                   description: |-
                                     ObjectMetaOverride provides the ability to override an object metadata.
@@ -3075,6 +3079,8 @@ spec:
                             deployment:
                               description: Override configuration for the temporal service Deployment.
                               properties:
+                                jsonPatch:
+                                  x-kubernetes-preserve-unknown-fields: true
                                 metadata:
                                   description: |-
                                     ObjectMetaOverride provides the ability to override an object metadata.
@@ -3246,6 +3252,8 @@ spec:
                             deployment:
                               description: Override configuration for the temporal service Deployment.
                               properties:
+                                jsonPatch:
+                                  x-kubernetes-preserve-unknown-fields: true
                                 metadata:
                                   description: |-
                                     ObjectMetaOverride provides the ability to override an object metadata.
@@ -3411,6 +3419,8 @@ spec:
                             deployment:
                               description: Override configuration for the temporal service Deployment.
                               properties:
+                                jsonPatch:
+                                  x-kubernetes-preserve-unknown-fields: true
                                 metadata:
                                   description: |-
                                     ObjectMetaOverride provides the ability to override an object metadata.
@@ -3549,6 +3559,8 @@ spec:
                         deployment:
                           description: Override configuration for the temporal service Deployment.
                           properties:
+                            jsonPatch:
+                              x-kubernetes-preserve-unknown-fields: true
                             metadata:
                               description: |-
                                 ObjectMetaOverride provides the ability to override an object metadata.
@@ -3637,6 +3649,8 @@ spec:
                             deployment:
                               description: Override configuration for the temporal service Deployment.
                               properties:
+                                jsonPatch:
+                                  x-kubernetes-preserve-unknown-fields: true
                                 metadata:
                                   description: |-
                                     ObjectMetaOverride provides the ability to override an object metadata.
@@ -3829,6 +3843,8 @@ spec:
                         deployment:
                           description: Override configuration for the temporal service Deployment.
                           properties:
+                            jsonPatch:
+                              x-kubernetes-preserve-unknown-fields: true
                             metadata:
                               description: |-
                                 ObjectMetaOverride provides the ability to override an object metadata.

docs/api/v1beta1.md

@@ -1400,6 +1400,18 @@ DeploymentOverrideSpec
 </table>
 </td>
 </tr>
+<tr>
+<td>
+<code>jsonPatch</code><br>
+<em>
+<a href="https://pkg.go.dev/k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1#JSON">
+k8s.io/apiextensions-apiserver/pkg/apis/apiextensions/v1.JSON
+</a>
+</em>
+</td>
+<td>
+</td>
+</tr>
 </tbody>
 </table>
 </div>
@@ -2388,7 +2400,7 @@ map[string]string
 <td>
 <code>override</code><br>
 <em>
-<a href="https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.ServiceMonitorSpec">
+<a href="https://prometheus-operator.dev/docs/operator/api/#monitoring.coreos.com/v1.ServiceMonitorSpec">
 github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1.ServiceMonitorSpec
 </a>
 </em>
@@ -2403,7 +2415,7 @@ All fields can be overwritten except &ldquo;endpoints&rdquo;, &ldquo;selector&rd
 <td>
 <code>metricRelabelings</code><br>
 <em>
-<a href="https://prometheus-operator.dev/docs/api-reference/api/#monitoring.coreos.com/v1.RelabelConfig">
+<a href="https://prometheus-operator.dev/docs/operator/api/#monitoring.coreos.com/v1.RelabelConfig">
 []github.com/prometheus-operator/prometheus-operator/pkg/apis/monitoring/v1.RelabelConfig
 </a>
 </em>

docs/features/overrides.md

@@ -15,6 +15,8 @@ The API provides you the ability to apply your overrides:
 - per temporal service (using `spec.services.[frontend|history|matching|worker].overrides`)
 - for all services (using `spec.services.overrides`)
 
+There are two ways of performing overrides, one is via StrategicPatchMerge and one using RFC6902 JSON patches. You can find examples of both below. If working with certain fields that aren't handled by StrategicPatchMerge properly (i.e., arrays that don't have go struct tags for merging valid for your use case), you may want to consider using JSON patches.
+
 ## Overrides for all services
 
 Here is a general example:
@@ -210,7 +212,7 @@ spec:
                         value: example.com
 ```
 
-### Example: mount an extra volume to the frontend pod
+### Example: Mount an extra secret volume to the frontend pod
 
 ```yaml
 apiVersion: temporal.io/v1beta1
@@ -223,18 +225,18 @@ spec:
     frontend:
       overrides:
         deployment:
-          spec:
-            template:
-              spec:
-                containers:
-                  - name: service
-                    volumeMounts:
-                      - name: extra-volume
-                        mountPath: /etc/extra
-                volumes:
-                  - name: extra-volume
-                    configMap:
-                      name: extra-config
+          jsonPatch:
+            - op: add
+              path: /spec/template/spec/containers/0/volumeMounts/-
+              value:
+                name: extra-volume
+                mountPath: /etc/extra
+            - op: add
+              path: /spec/template/spec/volumes/-
+              value:
+                name: extra-volume
+                secret:
+                  secretName: test-secret
 ```
 
 ### Example: Add an environment variable from secretRef to the frontend pod
@@ -286,6 +288,29 @@ spec:
                         service: frontend.temporal.temporal.svc.cluster.local
 ```
 
+### Example: Add environment variable from a secret to frontend pod
+```yaml
+apiVersion: temporal.io/v1beta1
+kind: TemporalCluster
+metadata:
+  name: prod
+spec:
+  # [...]
+  services:
+    frontend:
+      overrides:
+        deployment:
+          jsonPatch:
+            - op: add
+              path: /spec/template/spec/containers/0/env/-
+              value:
+                name: TEST
+                valueFrom:
+                  secretKeyRef:
+                    name: test-secret
+                    key: test
+```
+
 Read more in [Strategic Merge Patch](https://github.com/kubernetes/community/blob/master/contributors/devel/sig-api-machinery/strategic-merge-patch.md#strategic-merge-patch).
 
 ## Override UI deployment

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/alexandrevilain/controller-tools v0.3.0
 	github.com/cert-manager/cert-manager v1.16.1
 	github.com/elliotchance/orderedmap/v2 v2.4.0
+	github.com/evanphx/json-patch/v5 v5.9.0
 	github.com/go-logr/logr v1.4.2
 	github.com/gocql/gocql v1.7.0
 	github.com/google/uuid v1.6.0
@@ -53,7 +54,6 @@ require (
 	github.com/davecgh/go-spew v1.1.2-0.20180830191138-d8f796af33cc // indirect
 	github.com/dgryski/go-farm v0.0.0-20240924180020-3414d57e47da // indirect
 	github.com/emicklei/go-restful/v3 v3.12.1 // indirect
-	github.com/evanphx/json-patch/v5 v5.9.0 // indirect
 	github.com/facebookgo/clock v0.0.0-20150410010913-600d898af40a // indirect
 	github.com/felixge/httpsnoop v1.0.4 // indirect
 	github.com/fxamacker/cbor/v2 v2.7.0 // indirect

pkg/kubernetes/overrides.go

@@ -23,6 +23,7 @@ import (
 
 	"github.com/alexandrevilain/temporal-operator/api/v1beta1"
 	"github.com/alexandrevilain/temporal-operator/internal/metadata"
+	jsonpatch "github.com/evanphx/json-patch/v5"
 	appsv1 "k8s.io/api/apps/v1"
 	corev1 "k8s.io/api/core/v1"
 	"k8s.io/apimachinery/pkg/util/strategicpatch"
@@ -110,6 +111,24 @@ func ApplyDeploymentOverrides(deployment *appsv1.Deployment, override *v1beta1.D
 		}
 	}
 
+	if override.JSONPatch != nil {
+		patch, err := jsonpatch.DecodePatch(override.JSONPatch.Raw)
+		if err != nil {
+			return fmt.Errorf("can't decode json patch: %w", err)
+		}
+
+		original, err := json.Marshal(deployment)
+		if err != nil {
+			return fmt.Errorf("can't marshal deployment spec: %w", err)
+		}
+
+		patched, err := patch.Apply(original)
+		if err != nil {
+			return fmt.Errorf("can't apply json patch: %w", err)
+		}
+		return json.Unmarshal(patched, &deployment)
+	}
+
 	return nil
 }