ob-col/receiver/k8sclusterreceiver

Kubernetes Cluster Receiver

Status
Stability	beta: metrics
	development: logs
Distributions	contrib, observiq, splunk, sumo
Issues
Code Owners	@dmitryax, @TylerHelmuth, @povilasv

The Kubernetes Cluster receiver collects cluster-level metrics and entity events from the Kubernetes API server. It uses the K8s API to listen for updates. A single instance of this receiver should be used to monitor a cluster.

Currently, this receiver supports authentication via service accounts only. See example for more information.

Metrics

Details about the metrics produced by this receiver can be found in metadata.yaml and documentation.md.

Configuration

The following settings are required:

• auth_type (default = serviceAccount): Determines 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.

The following settings are optional:

• collection_interval (default = 10s): This receiver continuously watches for events using K8s API. However, the metrics collected are emitted only once every collection interval. collection_interval will determine the frequency at which metrics are emitted by this receiver.
• metadata_collection_interval (default = 5m): Collection interval for metadata for K8s entities such as pods, nodes, etc. Metadata of the particular entity in the cluster is collected when the entity changes. In addition, metadata of all entities is collected periodically even if no changes happen. This setting controls the interval between periodic collections. Setting the duration to 0 will disable periodic collection (however will not impact metadata collection on changes).
• node_conditions_to_report (default = [Ready]): An array of node conditions this receiver should report. See here for list of node conditions. The receiver will emit one metric per entry in the array.
• distribution (default = kubernetes): The Kubernetes distribution being used by the cluster. Currently supported versions are kubernetes and openshift. Setting the value to openshift enables OpenShift specific metrics in addition to standard kubernetes ones.
• allocatable_types_to_report (default = []): An array of allocatable resource types this receiver should report. The following allocatable resource types are available.
  • cpu
  • memory
  • ephemeral-storage
  • storage
• metrics: Allows to enable/disable metrics.
• resource_attributes: Allows to enable/disable resource attributes.

Example:

  k8s_cluster:
    auth_type: kubeConfig
    node_conditions_to_report: [Ready, MemoryPressure]
    allocatable_types_to_report: [cpu, memory]
  metrics:
    k8s.container.cpu_limit:
      enabled: false
  resource_attributes:
    container.id:
      enabled: false

The full list of settings exposed for this receiver are documented here with detailed sample configurations here.

node_conditions_to_report

For example, with the config below the receiver will emit two metrics k8s.node.condition_ready and k8s.node.condition_memory_pressure, one for each condition in the config. The value will be 1 if the ConditionStatus for the corresponding Condition is True, 0 if it is False and -1 if it is Unknown.

...
k8s_cluster:
  node_conditions_to_report:
    - Ready
    - MemoryPressure
...

metadata_exporters

A list of metadata exporters to which metadata being collected by this receiver should be synced. Exporters specified in this list are expected to implement the following interface. If an exporter that does not implement the interface is listed, startup will fail.

type MetadataExporter interface {
  ConsumeMetadata(metadata []*MetadataUpdate) error
}

type MetadataUpdate struct {
  ResourceIDKey string
  ResourceID    ResourceID
  MetadataDelta
}

type MetadataDelta struct {
  MetadataToAdd    map[string]string
  MetadataToRemove map[string]string
  MetadataToUpdate map[string]string
}

See here for details about the above types.

The same metadata will be also emitted as entity events in the form of log records if this receiver is connected to a logs pipeline. See here for the format of emitted log records.

Example

Here is an example deployment of the collector that sets up this receiver along with the debug exporter.

Follow the below sections to setup various Kubernetes resources required for the deployment.

Configuration

Create a ConfigMap with the config for otelcontribcol:

cat <<EOF | kubectl apply -f -
apiVersion: v1
kind: ConfigMap
metadata:
  name: otelcontribcol
  labels:
    app: otelcontribcol
data:
  config.yaml: |
    receivers:
      k8s_cluster:
        collection_interval: 10s
    exporters:
      debug:
    service:
      pipelines:
        metrics:
          receivers: [k8s_cluster]
          exporters: [debug]
        logs/entity_events:
          receivers: [k8s_cluster]
          exporters: [debug]
EOF

Service Account

Create a service account that the collector should use.

<<EOF | kubectl apply -f -
apiVersion: v1
kind: ServiceAccount
metadata:
  labels:
    app: otelcontribcol
  name: otelcontribcol
EOF

RBAC

Use the below commands to create a ClusterRole with required permissions and a ClusterRoleBinding to grant the role to the service account created above.

<<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: otelcontribcol
  labels:
    app: otelcontribcol
rules:
- apiGroups:
  - ""
  resources:
  - events
  - namespaces
  - namespaces/status
  - nodes
  - nodes/spec
  - pods
  - pods/status
  - replicationcontrollers
  - replicationcontrollers/status
  - resourcequotas
  - services
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - apps
  resources:
  - daemonsets
  - deployments
  - replicasets
  - statefulsets
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - extensions
  resources:
  - daemonsets
  - deployments
  - replicasets
  verbs:
  - get
  - list
  - watch
- apiGroups:
  - batch
  resources:
  - jobs
  - cronjobs
  verbs:
  - get
  - list
  - watch
- apiGroups:
    - autoscaling
  resources:
    - horizontalpodautoscalers
  verbs:
    - get
    - list
    - watch
EOF

<<EOF | kubectl apply -f -
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: otelcontribcol
  labels:
    app: otelcontribcol
roleRef:
  apiGroup: rbac.authorization.k8s.io
  kind: ClusterRole
  name: otelcontribcol
subjects:
- kind: ServiceAccount
  name: otelcontribcol
  namespace: default
EOF

Deployment

Create a Deployment to deploy the collector.

<<EOF | kubectl apply -f -
apiVersion: apps/v1
kind: Deployment
metadata:
  name: otelcontribcol
  labels:
    app: otelcontribcol
spec:
  replicas: 1
  selector:
    matchLabels:
      app: otelcontribcol
  template:
    metadata:
      labels:
        app: otelcontribcol
    spec:
      serviceAccountName: otelcontribcol
      containers:
      - name: otelcontribcol
        image: otel/opentelemetry-collector-contrib
        args: ["--config", "/etc/config/config.yaml"]
        volumeMounts:
        - name: config
          mountPath: /etc/config
        imagePullPolicy: IfNotPresent
      volumes:
        - name: config
          configMap:
            name: otelcontribcol
EOF

OpenShift

You can enable OpenShift support to collect OpenShift specific metrics in addition to the default kubernetes ones. To do this, set the distribution key to openshift.

Example:

  k8s_cluster:
    distribution: openshift

Add the following rules to your ClusterRole:

- apigroups:
  - quota.openshift.io
  resources:
  - clusterresourcequotas
  verbs:
  - get
  - list
  - watch