Follow these instructions to prepare an OpenShift cluster for Istio.
By default, OpenShift doesn't allow containers running with user ID 0.
You must enable containers running with UID 0 for Istio's service accounts
by running the command below. Make sure to replace
istio-system if you are
deploying Istio in another namespace:
$ oc adm policy add-scc-to-group anyuid system:serviceaccounts -n istio-system
Now you can install Istio using the CNI instructions.
After installation is complete, expose an OpenShift route for the ingress gateway.
$ oc -n istio-system expose svc/istio-ingressgateway --port=80
Automatic sidecar injection
Webhook and certificate signing requests support must be enabled for automatic injection to work. Modify the master configuration file on the master node for the cluster as follows.
In the same directory as the master configuration file, create a file named
master-config.patch with the following contents:
admissionConfig: pluginConfig: MutatingAdmissionWebhook: configuration: apiVersion: apiserver.config.k8s.io/v1alpha1 kubeConfigFile: /dev/null kind: WebhookAdmission ValidatingAdmissionWebhook: configuration: apiVersion: apiserver.config.k8s.io/v1alpha1 kubeConfigFile: /dev/null kind: WebhookAdmission
In the same directory, execute:
$ cp -p master-config.yaml master-config.yaml.prepatch $ oc ex config patch master-config.yaml.prepatch -p "$(cat master-config.patch)" > master-config.yaml $ master-restart api $ master-restart controllers
Privileged security context constraints for application sidecars
The Istio sidecar injected into each application pod runs with user ID 1337, which is not allowed by default in OpenShift. To allow this user ID to be used, execute the following commands. Replace
<target-namespace> with the appropriate namespace.
$ oc adm policy add-scc-to-group privileged system:serviceaccounts -n <target-namespace> $ oc adm policy add-scc-to-group anyuid system:serviceaccounts -n <target-namespace>
When removing your application, remove the permissions as follows.
$ oc adm policy remove-scc-from-group privileged system:serviceaccounts -n <target-namespace> $ oc adm policy remove-scc-from-group anyuid system:serviceaccounts -n <target-namespace>