Istio

The following sections describe how to connect the operator and managed resources to the Istio service mesh. It is assumed that Istio is already installed and configured on your Kubernetes cluster. If you are new to Istio, refer to the product documentation for more information and installation instructions.

The operator itself must be connected to the service mesh in order to deploy and manage Elastic Stack resources that you wish to connect to the service mesh. This is achieved by injecting an Istio sidecar to the ECK operator pods. The following instructions assume that automatic sidecar injection is enabled on your cluster via a mutating admissions webhook. Refer to Istio injection documentation if you prefer a different method of injection.

Create the elastic-system namespace and enable sidecar injection:

kubectl create namespace elastic-system
kubectl label namespace elastic-system istio-injection=enabled

Install ECK:

kubectl apply -f https://download.elastic.co/downloads/eck/1.0.1/all-in-one.yaml

Check the configuration to ensure that the installation has been successful:

kubectl get pod elastic-operator-0 -n elastic-system -o=jsonpath='{range .spec.containers[*]}{.name}{"\n"}'

If the output of the above command contains both manager and istio-proxy, ECK has been successfully installed with the Istio sidecar injected.

If you have configured Istio in permissive mode, examples defined elsewhere in the ECK documentation will continue to work without requiring any modifications. However, if you have enabled strict mutual TLS authentication between services either via global (MeshPolicy) or namespace-level (Policy) configuration, the following modifications to the resource manifests are necessary for correct operation.

apiVersion: elasticsearch.k8s.elastic.co/v1
kind: Elasticsearch
metadata:
  name: elastic-istio
spec:
  version: 8.15.3
  http:
    tls: 
      selfSignedCertificate:
        disabled: true
  nodeSets:
  - name: default
    count: 3
    config:
      node.store.allow_mmap: false
    podTemplate:
      metadata:
        annotations:
          traffic.sidecar.istio.io/excludeOutboundPorts: "9300" 
          traffic.sidecar.istio.io/excludeInboundPorts: "9300"

If you do not have automatic mutual TLS enabled, you may need to create a Destination Rule to allow the operator to communicate with the Elasticsearch cluster. A communication issue between the operator and the managed Elasticsearch cluster can be detected by looking at the operator logs to see if there are any errors reported with the text 503 Service Unavailable.

kubectl logs -f -n elastic-system -c manager statefulset.apps/elastic-operator

If the operator logs indicate a communications problem, create a DestinationRule to enable mutual TLS between the operator and the affected Elasticsearch cluster. For example, the following rule enables mutual TLS for a specific Elasticsearch cluster named elastic-istio deployed to the default namespace.

apiVersion: networking.istio.io/v1alpha3
kind: DestinationRule
metadata:
  name: elastic-istio
spec:
  host: "elastic-istio-es-http.default.svc.cluster.local"
  trafficPolicy:
    tls:
      mode: ISTIO_MUTUAL

Refer to the Istio documentation for more information about other configuration options affecting authentication between services.

apiVersion: kibana.k8s.elastic.co/v1
kind: Kibana
metadata:
  name: elastic-istio
spec:
  version: 8.15.3
  count: 1
  elasticsearchRef:
    name: elastic-istio
  http:
    tls: 
      selfSignedCertificate:
        disabled: true
  podTemplate:
    metadata:
      annotations:
        sidecar.istio.io/rewriteAppHTTPProbers: "true" 

apiVersion: apm.k8s.elastic.co/v1
kind: ApmServer
metadata:
  name: elastic-istio
spec:
  version: 8.15.3
  count: 1
  elasticsearchRef:
    name: elastic-istio
  http:
    tls: 
      selfSignedCertificate:
        disabled: true
  podTemplate:
    metadata:
      annotations:
        sidecar.istio.io/rewriteAppHTTPProbers: "true"