To run both Fleet Server and Elastic Agent in Fleet-managed mode, set the mode configuration element to fleet.

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: elastic-agent-sample
spec:
  mode: fleet

To run Fleet Server, set the fleetServerEnabled configuration element to true, as shown in this example:

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: fleet-server-sample
spec:
  mode: fleet
  fleetServerEnabled: true

You can leave the default value false for any other case.

To have Fleet running properly, the following settings must be correctly set in the Kibana configuration:

apiVersion: kibana.k8s.elastic.co/v1
kind: Kibana
metadata:
  name: kibana-sample
spec:
  config:
    xpack.fleet.agents.elasticsearch.hosts: ["https://elasticsearch-sample-es-http.default.svc:9200"]
    xpack.fleet.agents.fleet_server.hosts: ["https://fleet-server-sample-agent-http.default.svc:8220"]
    xpack.fleet.packages:
      - name: system
        version: latest
      - name: elastic_agent
        version: latest
      - name: fleet_server
        version: latest
    xpack.fleet.agentPolicies:
      - name: Fleet Server on ECK policy
        id: eck-fleet-server
        is_default_fleet_server: true
        namespace: default
        monitoring_enabled:
          - logs
          - metrics
        unenroll_timeout: 900
        package_policies:
        - name: fleet_server-1
          id: fleet_server-1
          package:
            name: fleet_server
      - name: Elastic Agent on ECK policy
        id: eck-agent
        namespace: default
        monitoring_enabled:
          - logs
          - metrics
        unenroll_timeout: 900
        is_default: true
        package_policies:
          - name: system-1
            id: system-1
            package:
              name: system

Both Fleet Server and Elastic Agent in Fleet mode can be automatically set up with Fleet by ECK. The ECK operator can set up Fleet in Kibana (which otherwise requires manual steps) and enroll Fleet Server in the default Fleet Server policy. Elastic Agent can be automatically enrolled in the default Elastic Agent policy. To allow ECK to set this up, provide a reference to a ECK-managed Kibana through the kibanaRef configuration element.

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: fleet-server-sample
spec:
  kibanaRef:
    name: kibana

ECK can also facilitate the connection between Elastic Agents and a ECK-managed Fleet Server. To allow ECK to set this up, provide a reference to Fleet Server through the fleetServerRef configuration element.

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: elastic-agent-sample
spec:
  fleetServerRef:
    name: fleet-server-sample

Set the elasticsearchRefs element in your Fleet Server to point to the Elasticsearch cluster that will manage Fleet. Leave elasticsearchRefs empty or unset it for any Elastic Agent running in Fleet mode as the Elasticsearch cluster to target will come from Kibana’s xpack.fleet.agents.elasticsearch.hosts configuration element.

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: fleet-server-sample
spec:
  elasticsearchRefs:
  - name: elasticsearch-sample

By default, every reference targets all instances in your Elasticsearch, Kibana and Fleet Server deployments, respectively. If you want to direct traffic to specific instances, refer to Traffic Splitting for more information and examples.

In contrast to Elastic Agents in standalone mode, the configuration is managed through Fleet, and it cannot be defined through config or configRef elements.

You can upgrade the Elastic Agent version or change settings by editing the YAML specification file. ECK applies the changes by performing a rolling restart of the Agent’s Pods. Depending on the settings that you used, ECK will set up Fleet in Kibana, enrolls the agent in Fleet, or restarts Elastic Agent on certificate rollover.

Depending on the use case, Elastic Agent may need to be deployed as a Deployment or a DaemonSet. To choose how to deploy your Elastic Agents, provide a podTemplate element under the deployment or the daemonSet element in the specification. If you choose the deployment option, you can additionally specify the strategy used to replace old Pods with new ones.

Similarly, you can set the update strategy when deploying as a DaemonSet. This allows you to control the rollout speed for new configuration by modifying the maxUnavailable setting:

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: elastic-agent-sample
spec:
  version: 8.13.3
  daemonSet:
    strategy:
      type: RollingUpdate
      rollingUpdate:
        maxUnavailable: 3
...

Refer to Set compute resources for Beats and Elastic Agent for more information on how to use the Pod template to adjust the resources given to Elastic Agent.

Some Elastic Agent features, such as the Kubernetes integration, require that Agent Pods interact with Kubernetes APIs. This functionality requires specific permissions. Standard Kubernetes RBAC rules apply. For example, to allow API interactions:

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: elastic-agent-sample
spec:
  version: 8.13.3
  elasticsearchRefs:
  - name: elasticsearch-sample
  daemonSet:
    podTemplate:
      spec:
        automountServiceAccountToken: true
        serviceAccountName: elastic-agent
...
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRole
metadata:
  name: elastic-agent
rules:
- apiGroups: [""] # "" indicates the core API group
  resources:
  - namespaces
  - pods
  - nodes
  - nodes/metrics
  - nodes/proxy
  - nodes/stats
  - events
  verbs:
  - get
  - watch
  - list
- nonResourceURLs:
  - /metrics
  verbs:
  - get
  - watch
  - list
---
apiVersion: v1
kind: ServiceAccount
metadata:
  name: elastic-agent
  namespace: default
---
apiVersion: rbac.authorization.k8s.io/v1
kind: ClusterRoleBinding
metadata:
  name: elastic-agent
subjects:
- kind: ServiceAccount
  name: elastic-agent
  namespace: default
roleRef:
  kind: ClusterRole
  name: elastic-agent
  apiGroup: rbac.authorization.k8s.io

To deploy Elastic Agent in clusters with the Pod Security Policy admission controller enabled, or in OpenShift clusters, you might need to grant additional permissions to the Service Account used by the Elastic Agent Pods. Those Service Accounts must be bound to a Role or ClusterRole that has use permission for the required Pod Security Policy or Security Context Constraints. Different Elastic Agent integrations might require different settings set in their PSP/SCC.

By default, ECK creates a Service for Fleet Server that Elastic Agents can connect through. You can customize it using the http configuration element. Check more information on how to make changes to the Service and customize the TLS configuration.

ECK uses the default policy to enroll Elastic Agents in Fleet and the default Fleet Server policy to enroll Fleet Server. A different policy can be chosen by using the policyID attribute in the Elastic Agent resource:

apiVersion: agent.k8s.elastic.co/v1alpha1
kind: Agent
metadata:
  name: fleet-server-sample
spec:
  policyID: my-custom-policy
...

Please note that the environment variables related to policy selection mentioned in the Elastic Agent docs like FLEET_SERVER_POLICY_ID will be managed by the ECK operator.