[processor/resourcedetection] introduce kubeadm detector (open-telemetry#35450)

**Description:** <Describe what has changed.>
<!--Ex. Fixing a bug - Describe the bug and how this fixes the issue.
Ex. Adding a feature - Explain what this achieves.-->
- introduce `kubeadm` detector to detect local cluster name

**Link to tracking Issue:** open-telemetry#35116

---------

Signed-off-by: odubajDT <[email protected]>
Co-authored-by: Christos Markou <[email protected]>

Author: 2 people

.chloggen/resourcedetection-local-cluster.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: resourcedetectionprocessor
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: "Introduce kubeadm detector to retrieve local cluster name."
+
+# Mandatory: One or more tracking issues related to the change. You can use the PR number here if no issue exists.
+issues: [35116]
+
+# (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: []

internal/metadataproviders/kubeadm/metadata.go

@@ -0,0 +1,56 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package kubeadm // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/metadataproviders/kubeadm"
+
+import (
+	"context"
+	"fmt"
+
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8sconfig"
+)
+
+type Provider interface {
+	// ClusterName returns the current K8S cluster name
+	ClusterName(ctx context.Context) (string, error)
+}
+
+type LocalCache struct {
+	ClusterName string
+}
+
+type kubeadmProvider struct {
+	kubeadmClient      kubernetes.Interface
+	configMapName      string
+	configMapNamespace string
+	cache              LocalCache
+}
+
+func NewProvider(configMapName string, configMapNamespace string, apiConf k8sconfig.APIConfig) (Provider, error) {
+	k8sAPIClient, err := k8sconfig.MakeClient(apiConf)
+	if err != nil {
+		return nil, fmt.Errorf("failed to create K8s API client: %w", err)
+	}
+	return &kubeadmProvider{
+		kubeadmClient:      k8sAPIClient,
+		configMapName:      configMapName,
+		configMapNamespace: configMapNamespace,
+	}, nil
+}
+
+func (k *kubeadmProvider) ClusterName(ctx context.Context) (string, error) {
+	if k.cache.ClusterName != "" {
+		return k.cache.ClusterName, nil
+	}
+	configmap, err := k.kubeadmClient.CoreV1().ConfigMaps(k.configMapNamespace).Get(ctx, k.configMapName, metav1.GetOptions{})
+	if err != nil {
+		return "", fmt.Errorf("failed to fetch ConfigMap with name %s and namespace %s from K8s API: %w", k.configMapName, k.configMapNamespace, err)
+	}
+
+	k.cache.ClusterName = configmap.Data["clusterName"]
+
+	return k.cache.ClusterName, nil
+}

internal/metadataproviders/kubeadm/metadata_test.go

@@ -0,0 +1,87 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package kubeadm
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	corev1 "k8s.io/api/core/v1"
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
+	"k8s.io/client-go/kubernetes/fake"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8sconfig"
+)
+
+func TestNewProvider(t *testing.T) {
+	// set k8s cluster env variables to make the API client happy
+	t.Setenv("KUBERNETES_SERVICE_HOST", "127.0.0.1")
+	t.Setenv("KUBERNETES_SERVICE_PORT", "6443")
+
+	_, err := NewProvider("name", "ns", k8sconfig.APIConfig{AuthType: k8sconfig.AuthTypeNone})
+	assert.NoError(t, err)
+}
+
+func TestClusterName(t *testing.T) {
+	client := fake.NewSimpleClientset()
+	err := setupConfigMap(client)
+	assert.NoError(t, err)
+
+	tests := []struct {
+		testName    string
+		CMname      string
+		CMnamespace string
+		clusterName string
+		errMsg      string
+	}{
+		{
+			testName:    "valid",
+			CMname:      "cm",
+			CMnamespace: "ns",
+			clusterName: "myClusterName",
+			errMsg:      "",
+		},
+		{
+			testName:    "configmap not found",
+			CMname:      "cm2",
+			CMnamespace: "ns",
+			errMsg:      "failed to fetch ConfigMap with name cm2 and namespace ns from K8s API: configmaps \"cm2\" not found",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.testName, func(t *testing.T) {
+			kubeadmP := &kubeadmProvider{
+				kubeadmClient:      client,
+				configMapName:      tt.CMname,
+				configMapNamespace: tt.CMnamespace,
+			}
+			clusterName, err := kubeadmP.ClusterName(context.Background())
+			if tt.errMsg != "" {
+				assert.EqualError(t, err, tt.errMsg)
+			} else {
+				assert.NoError(t, err)
+				assert.Equal(t, clusterName, tt.clusterName)
+			}
+		})
+	}
+}
+
+func setupConfigMap(client *fake.Clientset) error {
+	cm := &corev1.ConfigMap{
+		ObjectMeta: metav1.ObjectMeta{
+			Name:      "cm",
+			Namespace: "ns",
+		},
+		Data: map[string]string{
+			"clusterName": "myClusterName",
+		},
+	}
+	_, err := client.CoreV1().ConfigMaps("ns").Create(context.Background(), cm, metav1.CreateOptions{})
+	if err != nil {
+		return err
+	}
+	return nil
+}

internal/metadataproviders/kubeadm/package_test.go

@@ -0,0 +1,14 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package kubeadm
+
+import (
+	"testing"
+
+	"go.uber.org/goleak"
+)
+
+func TestMain(m *testing.M) {
+	goleak.VerifyTestMain(m)
+}

processor/resourcedetectionprocessor/README.md

@@ -426,6 +426,43 @@ processors:
     override: false
 ```
 
+### Kubeadm Metadata
+
+Queries the K8S API server to retrieve kubeadm resource attributes:
+
+The list of the populated resource attributes can be found at [kubeadm Detector Resource Attributes](./internal/kubeadm/documentation.md).
+
+The following permissions are required:
+```yaml
+kind: Role
+metadata:
+  name: otel-collector
+  namespace: kube-system
+rules:
+  - apiGroups: [""]
+    resources: ["configmaps"]
+    resourceNames: ["kubeadm-config"]
+    verbs: ["get"]
+---
+apiVersion: rbac.authorization.k8s.io/v1
+kind: RoleBinding
+metadata:
+  name: otel-collector-rolebinding
+  namespace: kube-system
+subjects:
+- kind: ServiceAccount
+  name: default
+  namespace: default
+roleRef:
+  kind: Role
+  name: otel-collector
+  apiGroup: rbac.authorization.k8s.io
+```
+
+| Name | Type | Required | Default         | Docs                                                                                                                                                                                                                                   |
+| ---- | ---- |----------|-----------------|----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
+| auth_type | string | No       | `serviceAccount` | How to authenticate to the K8s API server.  This can be one of `none` (for no auth), `serviceAccount` (to use the standard service account token provided to the agent pod), or `kubeConfig` to use credentials from `~/.kube/config`. |
+
 ### K8S Node Metadata
 
 Queries the K8S api server to retrieve node resource attributes.

processor/resourcedetectionprocessor/config.go

@@ -19,6 +19,7 @@ import (
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/gcp"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/heroku"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/k8snode"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/kubeadm"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/openshift"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/system"
 )
@@ -85,6 +86,9 @@ type DetectorConfig struct {
 
 	// K8SNode contains user-specified configurations for the K8SNode detector
 	K8SNodeConfig k8snode.Config `mapstructure:"k8snode"`
+
+	// Kubeadm contains user-specified configurations for the Kubeadm detector
+	KubeadmConfig kubeadm.Config `mapstructure:"kubeadm"`
 }
 
 func detectorCreateDefaultConfig() DetectorConfig {
@@ -103,6 +107,7 @@ func detectorCreateDefaultConfig() DetectorConfig {
 		SystemConfig:           system.CreateDefaultConfig(),
 		OpenShiftConfig:        openshift.CreateDefaultConfig(),
 		K8SNodeConfig:          k8snode.CreateDefaultConfig(),
+		KubeadmConfig:          kubeadm.CreateDefaultConfig(),
 	}
 }
 
@@ -136,6 +141,8 @@ func (d *DetectorConfig) GetConfigFromType(detectorType internal.DetectorType) i
 		return d.OpenShiftConfig
 	case k8snode.TypeStr:
 		return d.K8SNodeConfig
+	case kubeadm.TypeStr:
+		return d.KubeadmConfig
 	default:
 		return nil
 	}

processor/resourcedetectionprocessor/doc.go

@@ -16,6 +16,7 @@
 //go:generate mdatagen internal/openshift/metadata.yaml
 //go:generate mdatagen internal/system/metadata.yaml
 //go:generate mdatagen internal/k8snode/metadata.yaml
+//go:generate mdatagen internal/kubeadm/metadata.yaml
 
 // package resourcedetectionprocessor implements a processor
 // which can be used to detect resource information from the host,

processor/resourcedetectionprocessor/factory.go

@@ -32,6 +32,7 @@ import (
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/gcp"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/heroku"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/k8snode"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/kubeadm"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/metadata"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/openshift"
 	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/system"
@@ -66,6 +67,7 @@ func NewFactory() processor.Factory {
 		system.TypeStr:           system.NewDetector,
 		openshift.TypeStr:        openshift.NewDetector,
 		k8snode.TypeStr:          k8snode.NewDetector,
+		kubeadm.TypeStr:          kubeadm.NewDetector,
 	})
 
 	f := &factory{

processor/resourcedetectionprocessor/internal/kubeadm/config.go

@@ -0,0 +1,21 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package kubeadm // import "github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/kubeadm"
+
+import (
+	"github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8sconfig"
+	"github.com/open-telemetry/opentelemetry-collector-contrib/processor/resourcedetectionprocessor/internal/kubeadm/internal/metadata"
+)
+
+type Config struct {
+	k8sconfig.APIConfig `mapstructure:",squash"`
+	ResourceAttributes  metadata.ResourceAttributesConfig `mapstructure:"resource_attributes"`
+}
+
+func CreateDefaultConfig() Config {
+	return Config{
+		APIConfig:          k8sconfig.APIConfig{AuthType: k8sconfig.AuthTypeServiceAccount},
+		ResourceAttributes: metadata.DefaultResourceAttributesConfig(),
+	}
+}

processor/resourcedetectionprocessor/internal/kubeadm/documentation.md

@@ -0,0 +1,11 @@
+[comment]: <> (Code generated by mdatagen. DO NOT EDIT.)
+
+# resourcedetectionprocessor/kubeadm
+
+**Parent Component:** resourcedetection
+
+## Resource Attributes
+
+| Name | Description | Values | Enabled |
+| ---- | ----------- | ------ | ------- |
+| k8s.cluster.name | The Kubernetes cluster name | Any Str | true |