Run Elastic Agent on Kubernetes managed by Fleetedit

What you neededit

Step 1: Download the Elastic Agent manifestedit

You can find Elastic Agent Docker images here.

Download the manifest file:

curl -L -O https://raw.githubusercontent.com/elastic/elastic-agent/master/deploy/kubernetes/elastic-agent-managed-kubernetes.yaml

You might need to adjust resource limits of the Elastic Agent container in the manifest. Container resource usage depends on the number of data streams and the environment size.

This manifest includes the Kubernetes integration to collect Kubernetes metrics and System integration to collect system level metrics and logs from nodes.

The Elastic Agent is deployed as a DaemonSet to ensure that there is a running instance on each node of the cluster. These instances are used to retrieve most metrics from the host, such as system metrics, Docker stats, and metrics from all the services running on top of Kubernetes. These metrics are accessed through the deployed kube-state-metrics. Notice that everything is deployed under the kube-system namespace by default. To change the namespace, modify the manifest file.

Moreover, one of the Pods in the DaemonSet will constantly hold a leader lock which makes it responsible for handling cluster-wide monitoring. You can find more information about leader election configuration options at leader election provider. The leader pod will retrieve metrics that are unique for the whole cluster, such as Kubernetes events or kube-state-metrics.

The size and the number of nodes in a Kubernetes cluster can be fairly large at times, and in such cases the Pod that will be collecting cluster level metrics might face performance issues due to resources limitations. In this case users might consider to avoid using the leader election strategy and instead run a dedicated, standalone Elastic Agent instance using a Deployment in addition to the DaemonSet.

Step 2: Configure Elastic Agent policyedit

The Elastic Agent needs to be assigned to a policy to enable the proper inputs. To achieve Kubernetes observability, the policy needs to include the Kubernetes integration. Refer to Create a policy and Add an integration to a policy to learn how to configure the Kubernetes integration.

Step 3: Enroll Elastic Agent to the policyedit

Enrollment of an Elastic Agent is defined as the action to register a specific agent to a running Fleet Server.

Elastic Agent is enrolled to a running Fleet Server by using FLEET_URL parameter. Additionally, the FLEET_ENROLLMENT_TOKEN parameter is used to connect Elastic Agent to a specific Elastic Agent policy.

A new FLEET_ENROLLMENT_TOKEN will be created upon new policy creation and will be inserted inside the Elastic Agent Manifest during the Guided installation.

Find more information for Enrollment Tokens.

To specify different destination/credentials, change the following parameters in the manifest file:

- name: FLEET_URL
  value: "https://fleet-server_url:port" 
- name: FLEET_ENROLLMENT_TOKEN
  value: "token" 
- name: FLEET_SERVER_POLICY_ID
  value: "fleet-server-policy" 
- name: KIBANA_HOST
  value: "" 
- name: KIBANA_FLEET_USERNAME
  value: "" 
- name: KIBANA_FLEET_PASSWORD
  value: "" 

URL to enroll the Fleet Server into. You can find it in Kibana. Select Management → Fleet → Fleet Settings, and copy the Fleet Server host URL.

The token to use for enrollment. Close the flyout panel and select Enrollment tokens. Find the Agent policy you created before to enroll Elastic Agent into, and display and copy the secret token.

The policy ID for Fleet Server to use on itself.

The Kibana host.

The basic authentication username used to connect to Kibana and retrieve a service_token to enable Fleet.

The basic authentication password used to connect to Kibana and retrieve a service_token to enable Fleet.

Refer to Environment variables for all available options.

Step 4: Configure tolerationsedit

Kubernetes control plane nodes can use taints to limit the workloads that can run on them. The manifest for standalone Elastic Agent defines tolerations to run on these. Agents running on control plane nodes collect metrics from the control plane components (scheduler, controller manager) of Kubernetes. To disable Elastic Agent from running on control plane nodes, remove the following part of the DaemonSet spec:

spec:
  # Tolerations are needed to run Elastic Agent on Kubernetes control-plane nodes.
  # Agents running on control-plane nodes collect metrics from the control plane components (scheduler, controller manager) of Kubernetes
  tolerations:
    - key: node-role.kubernetes.io/control-plane
      effect: NoSchedule
    - key: node-role.kubernetes.io/master
      effect: NoSchedule

Both these two tolerations do the same, but node-role.kubernetes.io/master is deprecated as of Kubernetes version v1.25.

Step 5: Deploy the Elastic Agentedit

To deploy Elastic Agent to Kubernetes, run:

kubectl create -f elastic-agent-managed-kubernetes.yaml

To check the status, run:

$ kubectl -n kube-system get pods -l app=elastic-agent
NAME                            READY   STATUS    RESTARTS   AGE
elastic-agent-4665d             1/1     Running   0          81m
elastic-agent-9f466c4b5-l8cm8   1/1     Running   0          81m
elastic-agent-fj2z9             1/1     Running   0          81m
elastic-agent-hs4pb             1/1     Running   0          81m
Step 6: View your data in Kibanaedit
  1. Launch Kibana:

    1. Log in to your Elastic Cloud account.
    2. Navigate to the Kibana endpoint in your deployment.
  2. To check if your Elastic Agent is enrolled in Fleet, go to Management → Fleet → Agents.

    Elastic Agents Fleet page
  3. To view data flowing in, go to Analytics → Discover and select the index metrics-*, or even more specific, metrics-kubernetes.*. If you can’t see these indexes, create a data view for them.
  4. To view predefined dashboards, either select Analytics→Dashboard or install assets through an integration.