[processor/k8sattributesprocessor] Add support for missing k8s.cronjob.uid (open-telemetry#42641)

<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
#### Description

This PR adds support to expose `k8s.cronjob.uid` as resource metadata
when a `Job` is owned by a `CronJob`.

<!-- Issue number (e.g. open-telemetry#1234) or full URL to issue, if applicable. -->
#### Link to tracking issue

Fixes open-telemetry#42557

<!--Describe what testing was performed and which tests were added.-->
#### Testing

Local tested with `telemetrygen` and is working as expected.

```
[pod/k8sevents-receiver-opentelemetry-collector-6fd9966559-brlb6/opentelemetry-collector] {"level":"debug","ts":"2025-09-11T16:29:11.588Z","caller":"[email protected]/processor.go:159","msg":"getting the pod","resource":{"service.instance.id":"9631e38b-aec3-439f-8178-d96fc8368e1e","service.name":"otelcontribcol","service.version":"0.135.0-dev"},"otelcol.component.id":"k8sattributes","otelcol.component.kind":"processor","otelcol.pipeline.id":"traces","otelcol.signal":"traces","pod":{"Name":"otel-log-cronjob-29293469-lw97x","Address":"10.244.0.70","PodUID":"7960681c-5a24-4287-8bea-e2cf506500ee","Attributes":{"k8s.cronjob.name":"otel-log-cronjob","k8s.cronjob.uid":"082b1c42-e393-46bc-9d51-b20a3700d1ab","k8s.job.name":"otel-log-cronjob-29293469","k8s.job.uid":"fbd853b8-7f63-44d8-ace1-8b48c89e3041"},"StartTime":"2025-09-11T16:29:00Z","Ignore":false,"Namespace":"default","NodeName":"","DeploymentUID":"","StatefulSetUID":"","DaemonSetUID":"","JobUID":"fbd853b8-7f63-44d8-ace1-8b48c89e3041","HostNetwork":false,"Containers":{"ByID":null,"ByName":null},"DeletedAt":"0001-01-01T00:00:00Z"}}
[pod/k8sevents-receiver-opentelemetry-collector-6fd9966559-brlb6/opentelemetry-collector] {"level":"info","ts":"2025-09-11T16:29:11.588Z","msg":"Traces","resource":{"service.instance.id":"9631e38b-aec3-439f-8178-d96fc8368e1e","service.name":"otelcontribcol","service.version":"0.135.0-dev"},"otelcol.component.id":"debug","otelcol.component.kind":"exporter","otelcol.signal":"traces","resource spans":1,"spans":2}
[pod/k8sevents-receiver-opentelemetry-collector-6fd9966559-brlb6/opentelemetry-collector] {"level":"info","ts":"2025-09-11T16:29:11.588Z","msg":"ResourceSpans #0\nResource SchemaURL: https://opentelemetry.io/schemas/1.4.0\nResource attributes:\n     -> k8s.container.name: Str(telemetrygen)\n     -> service.name: Str(telemetrygen)\n     -> k8s.pod.ip: Str(10.244.0.70)\n     -> k8s.cronjob.name: Str(otel-log-cronjob)\n     -> k8s.cronjob.uid: Str(082b1c42-e393-46bc-9d51-b20a3700d1ab)\n     -> k8s.job.uid: Str(fbd853b8-7f63-44d8-ace1-8b48c89e3041)\n     -> k8s.job.name: Str(otel-log-cronjob-29293469)\nScopeSpans #0\nScopeSpans SchemaURL: \nInstrumentationScope telemetrygen \nSpan #0\n    Trace ID       : 3c7381c14a37814676b00a7d961cb219\n    Parent ID      : 4f8780d5148a9c1c\n    ID             : 17e9da9533dc93ca\n    Name           : okey-dokey-0\n    Kind           : Server\n    Start time     : 2025-09-11 16:29:09.583785469 +0000 UTC\n    End time       : 2025-09-11 16:29:09.583908469 +0000 UTC\n    Status code    : Unset\n    Status message : \nAttributes:\n     -> net.peer.ip: Str(1.2.3.4)\n     -> peer.service: Str(telemetrygen-client)\nSpan #1\n    Trace ID       : 3c7381c14a37814676b00a7d961cb219\n    Parent ID      : \n    ID             : 4f8780d5148a9c1c\n    Name           : lets-go\n    Kind           : Client\n    Start time     : 2025-09-11 16:29:09.583785469 +0000 UTC\n    End time       : 2025-09-11 16:29:09.583908469 +0000 UTC\n    Status code    : Unset\n    Status message : \nAttributes:\n     -> net.peer.ip: Str(1.2.3.4)\n     -> peer.service: Str(telemetrygen-server)\n","resource":{"service.instance.id":"9631e38b-aec3-439f-8178-d96fc8368e1e","service.name":"otelcontribcol","service.version":"0.135.0-dev"},"otelcol.component.id":"debug","otelcol.component.kind":"exporter","otelcol.signal":"traces"}
```

Added also the tests to guarantee the proper functionality.

---------

Signed-off-by: Paulo Dias <[email protected]>

Author: paulojmdias

.chloggen/feat_42557.yaml

@@ -0,0 +1,27 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: "enhancement"
+
+# The name of the component, or a single word describing the area of concern, (e.g. filelogreceiver)
+component: "processor/k8sattributesprocessor"
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Add support for k8s.cronjob.uid attribute in k8sattributesprocessor"
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [42557]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# If your change doesn't affect end users or the exported elements of any package,
+# you should instead start your pull request title with [chore] or use the "Skip Changelog" label.
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [user]

pkg/xk8stest/k8s_collector.go

@@ -5,6 +5,7 @@ package xk8stest // import "github.com/open-telemetry/opentelemetry-collector-co
 
 import (
 	"bytes"
+	"maps"
 	"os"
 	"path/filepath"
 	"testing"
@@ -39,9 +40,7 @@ func CreateCollectorObjects(t *testing.T, client *K8sClient, testID, manifestsDi
 			"HostEndpoint": host,
 			"TestID":       testID,
 		}
-		for key, value := range templateValues {
-			defaultTemplateValues[key] = value
-		}
+		maps.Copy(defaultTemplateValues, templateValues)
 		require.NoError(t, tmpl.Execute(manifest, defaultTemplateValues))
 		obj, err := CreateObject(client, manifest.Bytes())
 		require.NoErrorf(t, err, "failed to create collector object from manifest %s", manifestFile.Name())

pkg/xk8stest/k8s_telemetrygen.go

@@ -5,6 +5,7 @@ package xk8stest // import "github.com/open-telemetry/opentelemetry-collector-co
 
 import (
 	"bytes"
+	"fmt"
 	"os"
 	"path/filepath"
 	"testing"
@@ -31,6 +32,78 @@ type TelemetrygenCreateOpts struct {
 	DataTypes    []string
 }
 
+// getPodLabelSelectors returns labels used to select pods created by the workload.
+// - Deployment/StatefulSet/DaemonSet: spec.selector.matchLabels (fallback to template.metadata.labels)
+// - Job: spec.template.metadata.labels
+// - CronJob: spec.jobTemplate.spec.template.metadata.labels
+func getPodLabelSelectors(obj *unstructured.Unstructured) (map[string]any, error) {
+	o := obj.Object
+	spec, ok := o["spec"].(map[string]any)
+	if !ok || spec == nil {
+		return nil, fmt.Errorf("%s/%s missing spec", obj.GetKind(), obj.GetName())
+	}
+
+	switch obj.GetKind() {
+	case "Deployment", "StatefulSet", "DaemonSet":
+		if sel, ok := spec["selector"].(map[string]any); ok && sel != nil {
+			if ml, ok := sel["matchLabels"].(map[string]any); ok && ml != nil {
+				return ml, nil
+			}
+		}
+		// fallback — uncommon but robust
+		if tmpl, ok := spec["template"].(map[string]any); ok && tmpl != nil {
+			if meta, ok := tmpl["metadata"].(map[string]any); ok && meta != nil {
+				if ml, ok := meta["labels"].(map[string]any); ok && ml != nil {
+					return ml, nil
+				}
+			}
+		}
+		return nil, fmt.Errorf("%s/%s missing selector.matchLabels and template.metadata.labels", obj.GetKind(), obj.GetName())
+
+	case "Job":
+		if tmpl, ok := spec["template"].(map[string]any); ok && tmpl != nil {
+			if meta, ok := tmpl["metadata"].(map[string]any); ok && meta != nil {
+				if ml, ok := meta["labels"].(map[string]any); ok && ml != nil {
+					return ml, nil
+				}
+			}
+		}
+		// last resort if API server already defaulted it
+		if sel, ok := spec["selector"].(map[string]any); ok && sel != nil {
+			if ml, ok := sel["matchLabels"].(map[string]any); ok && ml != nil {
+				return ml, nil
+			}
+		}
+		return nil, fmt.Errorf("Job/%s missing template.metadata.labels (and selector.matchLabels)", obj.GetName())
+
+	case "CronJob":
+		jt, ok := spec["jobTemplate"].(map[string]any)
+		if !ok || jt == nil {
+			return nil, fmt.Errorf("CronJob/%s missing spec.jobTemplate", obj.GetName())
+		}
+		jts, ok := jt["spec"].(map[string]any)
+		if !ok || jts == nil {
+			return nil, fmt.Errorf("CronJob/%s missing spec.jobTemplate.spec", obj.GetName())
+		}
+		tmpl, ok := jts["template"].(map[string]any)
+		if !ok || tmpl == nil {
+			return nil, fmt.Errorf("CronJob/%s missing spec.jobTemplate.spec.template", obj.GetName())
+		}
+		meta, ok := tmpl["metadata"].(map[string]any)
+		if !ok || meta == nil {
+			return nil, fmt.Errorf("CronJob/%s missing spec.jobTemplate.spec.template.metadata", obj.GetName())
+		}
+		ml, ok := meta["labels"].(map[string]any)
+		if !ok || ml == nil {
+			return nil, fmt.Errorf("CronJob/%s missing spec.jobTemplate.spec.template.metadata.labels", obj.GetName())
+		}
+		return ml, nil
+
+	default:
+		return nil, fmt.Errorf("unsupported kind %q", obj.GetKind())
+	}
+}
+
 func CreateTelemetryGenObjects(t *testing.T, client *K8sClient, createOpts *TelemetrygenCreateOpts) ([]*unstructured.Unstructured, []*TelemetrygenObjInfo) {
 	telemetrygenObjInfos := make([]*TelemetrygenObjInfo, 0)
 	manifestFiles, err := os.ReadDir(createOpts.ManifestsDir)
@@ -48,10 +121,13 @@ func CreateTelemetryGenObjects(t *testing.T, client *K8sClient, createOpts *Tele
 			}))
 			obj, err := CreateObject(client, manifest.Bytes())
 			require.NoErrorf(t, err, "failed to create telemetrygen object from manifest %s", manifestFile.Name())
-			selector := obj.Object["spec"].(map[string]any)["selector"]
+
+			podLabels, err := getPodLabelSelectors(obj)
+			require.NoErrorf(t, err, "failed to extract pod label selectors for %s %s", obj.GetKind(), obj.GetName())
+
 			telemetrygenObjInfos = append(telemetrygenObjInfos, &TelemetrygenObjInfo{
 				Namespace:         obj.GetNamespace(),
-				PodLabelSelectors: selector.(map[string]any)["matchLabels"].(map[string]any),
+				PodLabelSelectors: podLabels,
 				DataType:          dataType,
 				Workload:          obj.GetKind(),
 			})

processor/k8sattributesprocessor/README.md

@@ -32,7 +32,7 @@ The processor stores the list of running pods and the associated metadata. When
 to the pod from where the datapoint originated, so we can add the relevant pod metadata to the datapoint. By default, it associates the incoming connection IP
 to the Pod IP. But for cases where this approach doesn't work (sending through a proxy, etc.), a custom association rule can be specified.
 
-Each association is specified as a list of sources of associations. The maximum number of sources within an association is 4. 
+Each association is specified as a list of sources of associations. The maximum number of sources within an association is 4.
 A source is a rule that matches metadata from the datapoint to pod metadata.
 In order to get an association applied, all the sources specified need to match.
 
@@ -63,16 +63,16 @@ If Pod association rules are not configured, resources are associated with metad
 
 Which metadata to collect is determined by `metadata` configuration that defines list of resource attributes
 to be added. Items in the list called exactly the same as the resource attributes that will be added.
-The following attributes are added by default: 
+The following attributes are added by default:
   - k8s.namespace.name
   - k8s.pod.name
   - k8s.pod.uid
   - k8s.pod.start_time
   - k8s.deployment.name
   - k8s.node.name
 
-These attributes are also available for the use within association rules by default. 
-The `metadata` section can also be extended with additional attributes which, if present in the `metadata` section, 
+These attributes are also available for the use within association rules by default.
+The `metadata` section can also be extended with additional attributes which, if present in the `metadata` section,
 are then also available for the use within association rules. Available attributes are:
   - k8s.namespace.name
   - k8s.pod.name
@@ -100,7 +100,7 @@ are then also available for the use within association rules. Available attribut
   - [service.instance.id](https://opentelemetry.io/docs/specs/semconv/non-normative/k8s-attributes/#how-serviceinstanceid-should-be-calculated)(cannot be used for source rules in the pod_association)
   - Any tags extracted from the pod labels and annotations, as described in [extracting attributes from pod labels and annotations](#extracting-attributes-from-pod-labels-and-annotations)
 
-Not all the attributes are guaranteed to be added. Only attribute names from `metadata` should be used for 
+Not all the attributes are guaranteed to be added. Only attribute names from `metadata` should be used for
 pod_association's `resource_attribute`, because empty or non-existing values will be ignored.
 
 Additional container level attributes can be extracted. If a pod contains more than one container,
@@ -204,7 +204,7 @@ the processor associates the received trace to the pod, based on the connection
     "k8s.pod.name": "telemetrygen-pod",
     "k8s.pod.uid": "038e2267-b473-489b-b48c-46bafdb852eb",
     "container.image.name": "telemetrygen",
-    "container.image.tag": "0.112.0", 
+    "container.image.tag": "0.112.0",
     "container.image.repo_digests": ["ghcr.io/open-telemetry/opentelemetry-collector-contrib/telemetrygen@sha256:b248ef911f93ae27cbbc85056d1ffacc87fd941bbdc2ffd951b6df8df72b8096"]
   }
 }
@@ -262,16 +262,16 @@ extract:
       from: node
 ```
 
-## Configuring recommended resource attributes 
+## Configuring recommended resource attributes
 
-The processor can be configured to set the 
+The processor can be configured to set the
 [recommended resource attributes](https://opentelemetry.io/docs/specs/semconv/non-normative/k8s-attributes/):
 
 - `otel_annotations` will translate `resource.opentelemetry.io/foo` to the `foo` resource attribute, etc.
 
 ```yaml
   extract:
-    otel_annotations: true 
+    otel_annotations: true
     metadata:
       - service.namespace
       - service.name
@@ -306,7 +306,7 @@ k8sattributes:
       - tag_name: app.label.component
         key: app.kubernetes.io/component
         from: pod
-    otel_annotations: true 
+    otel_annotations: true
   pod_association:
     - sources:
         # This rule associates all resources containing the 'k8s.pod.ip' attribute with the matching pods. If this attribute is not present in the resource, this rule will not be able to find the matching pod.
@@ -325,7 +325,7 @@ k8sattributes:
 
 ## Cluster-scoped RBAC
 
-If you'd like to set up the k8sattributesprocessor to receive telemetry from across namespaces, it will need `get`, `watch` and `list` permissions on both `pods` and `namespaces` resources, for all namespaces and pods included in the configured filters. Additionally, when using `k8s.deployment.name` (which is enabled by default) or `k8s.deployment.uid` the processor also needs `get`, `watch` and `list` permissions for `replicasets` resources. When using `k8s.node.uid` or extracting metadata from `node`, the processor needs `get`, `watch` and `list` permissions for `nodes` resources.
+If you'd like to set up the k8sattributesprocessor to receive telemetry from across namespaces, it will need `get`, `watch` and `list` permissions on both `pods` and `namespaces` resources, for all namespaces and pods included in the configured filters. Additionally, when using `k8s.deployment.name` (which is enabled by default) or `k8s.deployment.uid` the processor also needs `get`, `watch` and `list` permissions for `replicasets` resources. When using `k8s.node.uid` or extracting metadata from `node`, the processor needs `get`, `watch` and `list` permissions for `nodes` resources. When using `k8s.cronjob.uid` the processor also needs `get`, `watch` and `list` permissions for `jobs` resources.
 
 Here is an example of a `ClusterRole` to give a `ServiceAccount` the necessary permissions for all pods, nodes, and namespaces in the cluster (replace `<OTEL_COL_NAMESPACE>` with a namespace where collector is deployed):
 

processor/k8sattributesprocessor/client_test.go

@@ -31,6 +31,7 @@ type fakeClient struct {
 	Deployments        map[string]*kube.Deployment
 	StatefulSets       map[string]*kube.StatefulSet
 	DaemonSets         map[string]*kube.DaemonSet
+	ReplicaSets        map[string]*kube.ReplicaSet
 	Jobs               map[string]*kube.Job
 	StopCh             chan struct{}
 }
@@ -90,6 +91,11 @@ func (f *fakeClient) GetDaemonSet(daemonsetUID string) (*kube.DaemonSet, bool) {
 	return s, ok
 }
 
+func (f *fakeClient) GetReplicaSet(replicaSetUID string) (*kube.ReplicaSet, bool) {
+	rs, ok := f.ReplicaSets[replicaSetUID]
+	return rs, ok
+}
+
 func (f *fakeClient) GetJob(jobUID string) (*kube.Job, bool) {
 	j, ok := f.Jobs[jobUID]
 	return j, ok

processor/k8sattributesprocessor/config.go

@@ -97,7 +97,7 @@ func (cfg *Config) Validate() error {
 			string(conventions.K8SDaemonSetNameKey), string(conventions.K8SDaemonSetUIDKey),
 			string(conventions.K8SStatefulSetNameKey), string(conventions.K8SStatefulSetUIDKey),
 			string(conventions.K8SJobNameKey), string(conventions.K8SJobUIDKey),
-			string(conventions.K8SCronJobNameKey),
+			string(conventions.K8SCronJobNameKey), string(conventions.K8SCronJobUIDKey),
 			string(conventions.K8SNodeNameKey), string(conventions.K8SNodeUIDKey),
 			string(conventions.K8SContainerNameKey), string(conventions.ContainerIDKey),
 			string(conventions.ContainerImageNameKey), string(conventions.ContainerImageTagKey),
@@ -139,7 +139,8 @@ type ExtractConfig struct {
 	//   k8s.node.name, k8s.namespace.name, k8s.pod.start_time,
 	//   k8s.replicaset.name, k8s.replicaset.uid,
 	//   k8s.daemonset.name, k8s.daemonset.uid,
-	//   k8s.job.name, k8s.job.uid, k8s.cronjob.name,
+	//   k8s.job.name, k8s.job.uid,
+	//   k8s.cronjob.name, k8s.cronjob.uid,
 	//   k8s.statefulset.name, k8s.statefulset.uid,
 	//   k8s.container.name, container.id, container.image.name,
 	//   container.image.tag, container.image.repo_digests

processor/k8sattributesprocessor/documentation.md

@@ -13,6 +13,7 @@
 | k8s.cluster.uid | Gives cluster uid identified with kube-system namespace | Any Str | false |
 | k8s.container.name | The name of the Container in a Pod template. Requires container.id. | Any Str | false |
 | k8s.cronjob.name | The name of the CronJob. | Any Str | false |
+| k8s.cronjob.uid | The uid of the CronJob. | Any Str | false |
 | k8s.daemonset.name | The name of the DaemonSet. | Any Str | false |
 | k8s.daemonset.uid | The UID of the DaemonSet. | Any Str | false |
 | k8s.deployment.name | The name of the Deployment. | Any Str | true |