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Kubernetes

StackState SaaS

Overview

The Kubernetes integration is used to create a near real-time synchronization of topology and associated internal services from a Kubernetes cluster to StackState. This StackPack allows monitoring of the following:
  • Workloads
  • Nodes, pods, containers and services
  • Configmaps, secrets and volumes
Data flow
The Kubernetes integration collects topology data in a Kubernetes cluster as well as metrics and events.
  • Data is retrieved by the deployed StackState Agents and then pushed to StackState via the Agent StackPack and the Kubernetes StackPack.
  • In StackState:
    • Topology data is translated into components and relations.
    • Tags defined in Kubernetes are added to components and relations in StackState.
    • Metrics data is stored and accessible within StackState. Relevant metrics data is mapped to associated components and relations in StackState.
    • Kubernetes events are available in the StackState UI Events Perspective. They are also included in the Event list in the right panel View summary tab and the details tabs - Component details and Direct relation details.
    • Object change events are created for every detected change to spec or metadata in Kubernetes objects

Setup

Prerequisites

The following prerequisites are required to install the Kubernetes StackPack and deploy the StackState Agent and Cluster Agent:
  • A Kubernetes Cluster must be up and running.
  • A recent version of Helm 3.
  • A user with permissions to create privileged pods, ClusterRoles and ClusterRoleBindings:
    • ClusterRole and ClusterRoleBinding are needed to grant StackState Agents permissions to access the Kubernetes API.
    • StackState Agents need to run in a privileged pod to be able to gather information on network connections and host information.

Supported container runtimes

From StackState Agent V2.16, the following container runtimes are supported:
  • containerd
  • CRI-O
  • Docker
Note that versions of StackState Agent prior to v2.16 support the Docker container runtime only.

Install

Install the Kubernetes StackPack from the StackState UI StackPacks > Integrations screen. You will need to provide the following parameters:
  • Kubernetes Cluster Name - A name to identify the cluster. This does not need to match the cluster name used in kubeconfig, however, that is usually a good candidate for a unique name.
If the Agent StackPack is not already installed, this will be automatically installed together with the Kubernetes StackPack. This is required to work with the StackState Agent, which will need to be deployed on each node in the Kubernetes cluster.

Deploy: Agent and Cluster Agent

For the Kubernetes integration to retrieve topology, events and metrics data, you will need to have the following installed on your Kubernetes cluster:
  • StackState Agent V2 on each node in the cluster
  • StackState Cluster Agent on one node
  • StackState Checks Agent on one node
  • kube-state-metrics
To integrate with other services, a separate instance of the StackState Agent should be deployed on a standalone VM. It is not currently possible to configure a StackState Agent deployed on a Kubernetes cluster with checks that integrate with other services.

Configure kube-state-metrics

The kubernetes_state check is responsible for gathering metrics from kube-state-metrics and sending them to StackState. The kubernetes_state check runs in the StackState Checks Agent by default and is configured in the StackState Cluster Agent.
The default URL that the kubernetes_state check uses is:
http://<release-name>-kube-state-metrics.<namespace>.svc.cluster.local:8080/metrics
If an alternative kube-state-metrics pod (i.e. Prometheus) is installed, the default StackState kube-state-metrics pod can be disabled and the kubernetes_state check redirected to the alternative service:
  1. 1.
    Update the values.yaml file used to deploy the checks-agent, for example:
    dependencies:
    kubeStateMetrics:
    enabled: false
    checksAgent:
    kubeStateMetrics:
    url: http://YOUR_KUBE_STATE_METRICS_SERVICE_NAME:8080/metrics
  2. 2.
    Deploy the cluster_agent using the updated values.yaml:
    helm upgrade --install \
    --namespace stackstate \
    --create-namespace \
    --set-string 'stackstate.apiKey'='<STACKSTATE_RECEIVER_API_KEY>' \
    --set-string 'stackstate.cluster.name'='<KUBERNETES_CLUSTER_NAME>' \
    --set-string 'stackstate.cluster.authToken=<CLUSTER_AUTH_TOKEN>' \
    --set-string 'stackstate.url'='<STACKSTATE_RECEIVER_API_ADDRESS>' \
    --values values.yaml \
    stackstate-agent stackstate/stackstate-agent

Status

To check the status of the Kubernetes integration, check that the StackState Cluster Agent (cluster-agent) pod, StackState Checks Agent pod (checks-agent) and all of the StackState Agent (node-agent) pods have status ready.
❯ kubectl get deployment,daemonset --namespace stackstate
NAME READY UP-TO-DATE AVAILABLE AGE
deployment.apps/stackstate-agent-cluster-agent 1/1 1 1 5h14m
deployment.apps/stackstate-agent-checks-agent 1/1 1 1 5h14m
NAME DESIRED CURRENT READY UP-TO-DATE AVAILABLE NODE SELECTOR AGE
daemonset.apps/stackstate-agent-node-agent 10 10 10 10 10 <none> 5h14m

Integration details

Data retrieved

The Kubernetes integration retrieves the following data:

Events

Kubernetes events
The Kubernetes integration retrieves all events from the Kubernetes cluster. The table below shows which event category will be assigned to each event type in StackState:
StackState event category
Kubernetes events
Activities
BackOff ContainerGCFailed ExceededGracePeriod FileSystemResizeSuccessful ImageGCFailed Killing NodeAllocatableEnforced NodeNotReady NodeSchedulable Preempting Pulling Pulled Rebooted Scheduled Starting Started SuccessfulAttachVolume SuccessfulDetachVolume SuccessfulMountVolume SuccessfulUnMountVolume VolumeResizeSuccessful
Alerts
NotTriggerScaleUp
Changes
Created (created container) NodeReady SandboxChanged SuccessfulCreate SuccessfulDelete Completed
Others
All other events
Object change events
The Kubernetes integration will detect changes in Kubernetes objects and will create an event of type Element Properties Change with a diff with a YAML representation of the changed object.
Element Properties Change event
Changes will be detected in the following object types:
  • ConfigMap
  • CronJob
  • DaemonSet
  • Deployment
  • Ingress
  • Job
  • Namespace
  • Node
  • PersistentVolume
  • Pod
  • ReplicaSet
  • Secret (a hash of the content will be compared)
  • Service
  • StatefulSet
Note that, in order to reduce noise of changes, the following object properties will not be compared:
  • metadata
    • managedFields
    • resourceVersion
    • annotations
      • kubectl.kubernetes.io/last-applied-configuration
  • status (except for Node, Pod and PersistentVolume objects)
You can also see the current or past YAML definition of the object in the Component properties:
Kubernetes Component properties

Metrics

The Kubernetes integration makes all metrics from the Kubernetes cluster available in StackState. Relevant metrics are automatically mapped to the associated components.
All retrieved metrics can be browsed or added to a component as a telemetry stream. Select the data source StackState Metrics and type kubernetes in the Select box to get a full list of all available metrics.
Add a Kubernetes metrics stream to a component

Topology

The Kubernetes integration retrieves components and relations for the Kubernetes cluster.
StackState Agent versions prior to 2.16: Topology information is only gathered from Kubernetes clusters that use the Docker container runtime.
Components
The following Kubernetes topology data is available in StackState as components:
Cluster
Ingress
Namespace
Job
Node
Persistent Volume
Pod
ReplicaSet
Container
Secret
ConfigMap
Service
CronJob
StatefulSet
DaemonSet
Volume
Deployment
Relations
The following relations between components are retrieved:
  • Container → PersistentVolume, Volume
  • CronJob → Job
  • DaemonSet → Pod
  • Deployment → ReplicaSet
  • Job → Pod
  • Ingress → Service
  • Namespace → CronJob, DaemonSet, Deployment, Job, ReplicaSet, Service, StatefulSet
  • Node → Cluster relation
  • Pod → ConfigMap, Container, Deployment, Node, Secret, Volume
  • ReplicaSet → Pod
  • Service → ExternalService, Pod
  • StatefulSet → Pod
  • Direct communication between processes
  • Process → Process communication via Kubernetes service
  • Process → Process communication via headless Kubernetes service

Traces

The Kubernetes integration does not retrieve any traces data.

Tags

All tags defined in Kubernetes will be retrieved and added to the associated components and relations in StackState as labels.
The following labels will also be added to imported elements as relevant:
  • image_name
  • kube_cluster_name
  • kube_container_name
  • kube_cronjob
  • kube_daemon_set
  • kube_deployment
  • kube_job
  • kube_namespace
  • kube_replica_set
  • kube_replication_controller
  • kube_stateful_set
  • pod_name
  • pod_phase

REST API endpoints

The StackState Agent talks to the kubelet and kube-state-metrics API.
The StackState Agent and Cluster Agent connect to the Kubernetes API to retrieve cluster wide information and Kubernetes events. The following API endpoints used:
Resource type
REST API endpoint
Cluster > ComponentStatus
GET /api/v1/componentstatuses
Cluster > Event
GET /apis/events.k8s.io/v1/events
Cluster > Namespace
GET /api/v1/namespaces
Cluster > Node
GET /api/v1/nodes
Services > Endpoints
GET /api/v1/namespaces/{namespace}/endpoints
Services > Ingress
GET /apis/networking.k8s.io/v1/namespaces/{namespace}/ingresses
Services > Service
GET /api/v1/namespaces/{namespace}/services
Workloads > CronJob
GET /apis/batch/v1beta1/namespaces/{namespace}/cronjobs
Workloads > DaemonSet
GET /apis/apps/v1/namespaces/{namespace}/daemonsets
Workloads > Deployment
GET /apis/apps/v1/namespaces/{namespace}/deployments
Workloads > Job
GET /apis/batch/v1/namespaces/{namespace}/jobs
Workloads > Pod
GET /api/v1/namespaces/{namespace}/pods
Workloads > ReplicaSet
GET /apis/apps/v1/namespaces/{namespace}/replicasets
Workloads > StatefulSet
GET /apis/apps/v1/namespaces/{namespace}/statefulsets
Config and Storage > ConfigMap
GET /api/v1/namespaces/{namespace}/configmaps
Config and Storage > Secret
GET /api/v1/secrets
Config and Storage > PersistentVolume
GET /api/v1/persistentvolumes
Config and Storage > PersistentVolumeClaimSpec
GET /api/v1/namespaces/{namespace}/persistentvolumeclaims
Config and Storage > VolumeAttachment
GET /apis/storage.k8s.io/v1/volumeattachments
/version
/healthz
For further details, refer to the Kubernetes API documentation (kubernetes.io).

Component actions

A number of actions are added to StackState when the Kubernetes StackPack is installed. They are available from the Actions section in the right panel details tab - Component details - when a Kubernetes component is selected or from the component context menu, displayed when you hover the mouse pointer over a Kubernetes component in the Topology Perspective
Action
Available for component types
Description
Show configuration and storage
pods containers
Display the selected pod or container with its configmaps, secrets and volumes
Show dependencies (deep)
deployment replicaset replicationcontroller statefulset daemonset job cronjob pod
Displays all dependencies (up to 6 levels deep) of the selected pod or workload.
Show pods
deployment replicaset replicationcontroller statefulset daemonset job cronjob
Displays the pods for the selected workload.
Show pods and services
namespace
Opens a view for the pods/services in the selected namespace
Show services
namespace
Open a view for the service and ingress components in the selected namespace
Show workloads
namespace
Show workloads in the selected namespace
Details of installed actions can be found in the StackState UI Settings > Actions > Component Actions screen.

Kubernetes views in StackState

When the Kubernetes integration is enabled, the following Kubernetes views are available in StackState for each cluster:
  • Kubernetes - Applications -
  • Kubernetes - Infrastructure -
  • Kubernetes - Namespaces -
  • Kubernetes - Workload Controllers -

Open source

The code for the StackState Agent Kubernetes check is open source and available on GitHub at:

Troubleshooting

Troubleshooting steps for any known issues can be found in the StackState support Knowledge base.

Uninstall

To uninstall the Kubernetes StackPack, go to the StackState UI StackPacks > Integrations > Kubernetes screen and click UNINSTALL. All Kubernetes StackPack specific configuration will be removed from StackState.
See the Kubernetes Agent documentation for instructions on how to uninstall the StackState Cluster Agent and the StackState Agent from your Kubernetes cluster.

Release notes

Kubernetes StackPack v3.10.2 (2022-09-28)
  • Improvement: Updated documentation.
Kubernetes StackPack v3.10.1 (2022-09-15)
  • Improvement: Added validation for cluster name
Kubernetes StackPack v3.9.13 (2022-06-21)
  • Bug Fix: Fixed description for services/ingresses view.
Kubernetes StackPack v3.9.12 (2022-06-03)
  • Improvement: Updated documentation.
Kubernetes StackPack v3.9.11 (2022-05-23)
  • Bug Fix: Fixed broken link in integration StackState Agent V2 integration documentation.
Kubernetes StackPack v3.9.10 (2022-04-11)
  • Bug Fix: Show kubernetes view names on StackPack instance
Kubernetes StackPack v3.9.9 (2022-03-02)
  • Improvement: Documentation for agent.containerRuntime.customSocketPath option.
Kubernetes StackPack v3.9.8 (2021-11-30)
  • Bug Fix: Support nodes without instanceId

See also