Q: How can I enable/disable mTLS encryption after I installed Istio?

The most straightforward way to enable/disable mTLS is by entirely uninstalling and re-installing Istio.

If you are an advanced user and understand the risks you can also do the following:

kubectl edit configmap -n istio-system istio

comment out or uncomment out authPolicy: MUTUAL_TLS to toggle mTLS and then

kubectl delete pods -n istio-system -l istio=pilot

to restart Pilot, after a few seconds (depending on your *RefreshDelay) your Envoy proxies will have picked up the change from Pilot. During that time your services may be unavailable.

We are working on a smoother solution.

Q: Can a service with Istio Auth enabled communicate with a service without Istio?

This is not supported currently, but will be in the near future.

Q: Can I enable Istio Auth with some services while disable others in the same cluster?

Starting with release 0.3, you can use service-level annotations to disable (or enable) Istio Auth for particular service-port. The annotation key should be{port_number}, and the value should be NONE (to disable), or MUTUAL_TLS (to enable).

Example: disable Istio Auth on port 9080 for service details.

kind: Service
name: details
  app: details
annotations: NONE

Q: How can I use Kubernetes liveness and readiness for service health check with Istio Auth enabled?

If Istio Auth is enabled, http and tcp health check from kubelet will not work since they do not have Istio Auth issued certs. A workaround is to use a liveness command for health check, e.g., one can install curl in the service pod and curl itself within the pod. The Istio team is actively working on a solution.

An example of readinessProbe:

  - curl
  - -f
  - http://localhost:8080/healthz # Replace port and URI by your actual health check
initialDelaySeconds: 10
periodSeconds: 5

Q: Can I access the Kubernetes API Server with Auth enabled?

The Kubernetes API server does not support mutual TLS authentication, so strictly speaking: no. However, if you use version 0.3 or later, see next question to learn how to disable mTLS in upstream config on clients side so they can access API server.

Q: How to disable Auth on clients to access the Kubernetes API Server (or any control services that don't have Istio sidecar)?

Starting with release 0.3, edit the mtlsExcludedServices list in Istio config map to contain the fully-qualified name of the API server (and any other control services for that matter). The default value of mtlsExcludedServices already contains kubernetes.default.svc.cluster.local, which is the default service name of the Kubernetes API server.

For a quick reference, here are commands to edit Istio configmap and to restart pilot.

kubectl edit configmap -n istio-system istio
kubectl delete pods -n istio-system -l istio=pilot

Note: DO NOT use this approach to disable mTLS for services that are managed by Istio (i.e. using Istio sidecar). Instead, use service-level annotations to overwrite the authentication policy (see above).

Q: Does Istio Auth support authorization?

Yes. Starting from Istio 0.5 release, we provide Role Based Access Control for services in Istio mesh. Learn more.

Q: Does Istio Auth use Kubernetes secrets?

Yes. The key and certificate distribution in Istio Auth is based on Kubernetes secrets.

Secrets have known security risks. The kubernetes team is working on several features to improve Kubernetes secret security, from secret encryption to node-level access control. And as of version 1.6, Kubernetes introduces RBAC authorization, which can provide fine-grained secrets management.

Q: How to configure Istio Ingress to only accept TLS traffic?

By following the instructions on Configuring secure ingress, Istio Ingress can be secured to only accept TLS traffic.