Technology Preview - Istio Service Mesh Application¶
About this task
The Istio Service Mesh application Technology Preview is integrated into StarlingX as a system application.
Istio provides traffic management, observability as well as security as a Kubernetes service mesh. For more information, see https://istio.io/.
StarlingX includes istio-operator container to manage the life cycle management of the Istio components.
The following Istio components are enabled when applying the Istio system application:
Istio data plane - Envoy - Kubernetes side-car proxy
Istio control plane - Istiod - service discovery, configuration and certificate management
Istio gateway - Traffic management of ingress and egress L4-L7 traffic
Istio-cni - Kubernetes CNI plugin
The Kiali (https://kiali.io/) management console for Istio is also integrated with StarlingX in the Istio system application. It provides management functions and visualizations to the service mesh operation. Metrics and tracing functionalities are not supported at this time.
Procedure
You can install Istio and Kiali on StarlingX from the command line.
Locate the Istio tarball in
/usr/local/share/applications/helm
.For example:
/usr/local/share/applications/helm/istio-<version>.tgz
Upload the application.
~(keystone_admin)]$ system application-upload /usr/local/share/applications/helm/istio-<version>.tgz
Apply the application.
~(keystone_admin)]$ system application-apply istio
Monitor the application status.
~(keystone_admin)]$ watch -n 5 system application-list
OR
~(keystone_admin)]$ watch kubectl get pods -n istio-system
Setup network attachment definition.
cat > istio-cni-nad.yaml <<EOF apiVersion: "k8s.cni.cncf.io/v1" kind: NetworkAttachmentDefinition metadata: name: istio-cni EOF kubectl apply -f istio-cni-nad.yaml
CNI is managed by Multus. The
NetworkAttachmentDefinition
is required in the application namespace in order to invoke theistio-cni
plugin.Enable side car for a particular namespace.
kubectl label namespace <namespace> istio-injection=enabled
When the
istio-injection=enabled
label on a namespace is set and the injection webhook is enabled, any new pods that are created in that namespace will automatically have a sidecar added to them.
Results
At this point, you may have launched services in the above namespace.
When the user application is deployed, the sidecar container
istio-proxy
is injected into the user application pod:
Events:
Type Reason Age From Message
---- ------ ---- ---- -------
...
Normal Created 10s kubelet Created container <user app>
Normal Started 10s kubelet Started container <user app>
...
Normal Created 9s kubelet Created container istio-proxy
Normal Started 8s kubelet Started container istio-proxy
The istio-proxy
sidecar extracts telemetry of all ingress and egress
traffic of the user application that can be monitored and available for
display in Kiali, and it mediates all ingress and egress traffic of the
user application by enforcing policy decisions.
Use Kiali¶
After the Istio application has been installed, you can launch the Kiali management console in a browser.
Get the port of Kiali service.
~(keystone_admin)]$ kubectl get svc -n istio-system kiali -o jsonpath='{.spec.ports[?(@.name=="http")].nodePort}'
Launch Kiali on a browser.
http:<oam-floating-ip>:<kiali_port>/kiali
Get the login token.
~(keystone_admin)]$ kubectl get secret -n istio-system $(kubectl get sa kiali -n istio-system -o jsonpath='{.secrets[0].name}') -o jsonpath='{.data.token}' | base64 -d
Login to Kiali.
Enter the token from the previous step and press Login.
Remove Istio application¶
You can remove the Istio application from StarlingX.
Remove pods and their resources.
~(keystone_admin)]$ system application-remove istio
Delete the application.
~(keystone_admin)]$ system application-delete istio
Delete Istio CNI Network Attachment Definition.
~(keystone_admin)]$ kubectl delete -f istio-cni-nad.yaml