Chapter 6. Postinstallation network configuration After installing OpenShift Container Platform, you can further expand and customize your network to your requirements. 6.1. Using the Cluster Network Operator You can use the Cluster Network Operator (CNO) to deploy and manage cluster network components on an OpenShift Container Platform cluster, including the Container Network Interface (CNI) network plugin selected for the cluster during installation. For more information, see Cluster Network Operator in OpenShift Container Platform . 6.2. Network configuration tasks Configuring the cluster-wide proxy Configuring ingress cluster traffic overview Configuring the node port service range Configuring IPsec encryption Create a network policy or configure multitenant isolation with network policies Optimizing routing Understanding multiple networks 6.2.1. Creating default network policies for a new project As a cluster administrator, you can modify the new project template to automatically include NetworkPolicy objects when you create a new project. 6.2.1.1. Modifying the template for new projects As a cluster administrator, you can modify the default project template so that new projects are created using your custom requirements. To create your own custom project template: Prerequisites You have access to an OpenShift Container Platform cluster using an account with cluster-admin permissions. Procedure Log in as a user with cluster-admin privileges. Generate the default project template: USD oc adm create-bootstrap-project-template -o yaml > template.yaml Use a text editor to modify the generated template.yaml file by adding objects or modifying existing objects. The project template must be created in the openshift-config namespace. Load your modified template: USD oc create -f template.yaml -n openshift-config Edit the project configuration resource using the web console or CLI. Using the web console: Navigate to the Administration Cluster Settings page. Click Configuration to view all configuration resources. Find the entry for Project and click Edit YAML . Using the CLI: Edit the project.config.openshift.io/cluster resource: USD oc edit project.config.openshift.io/cluster Update the spec section to include the projectRequestTemplate and name parameters, and set the name of your uploaded project template. The default name is project-request . Project configuration resource with custom project template apiVersion: config.openshift.io/v1 kind: Project metadata: # ... spec: projectRequestTemplate: name: <template_name> # ... After you save your changes, create a new project to verify that your changes were successfully applied. 6.2.1.2. Adding network policies to the new project template As a cluster administrator, you can add network policies to the default template for new projects. OpenShift Container Platform will automatically create all the NetworkPolicy objects specified in the template in the project. Prerequisites Your cluster uses a default CNI network plugin that supports NetworkPolicy objects, such as the OVN-Kubernetes. You installed the OpenShift CLI ( oc ). You must log in to the cluster with a user with cluster-admin privileges. You must have created a custom default project template for new projects. Procedure Edit the default template for a new project by running the following command: USD oc edit template <project_template> -n openshift-config Replace <project_template> with the name of the default template that you configured for your cluster. The default template name is project-request . In the template, add each NetworkPolicy object as an element to the objects parameter. The objects parameter accepts a collection of one or more objects. In the following example, the objects parameter collection includes several NetworkPolicy objects. objects: - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-same-namespace spec: podSelector: {} ingress: - from: - podSelector: {} - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-openshift-ingress spec: ingress: - from: - namespaceSelector: matchLabels: network.openshift.io/policy-group: ingress podSelector: {} policyTypes: - Ingress - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-kube-apiserver-operator spec: ingress: - from: - namespaceSelector: matchLabels: kubernetes.io/metadata.name: openshift-kube-apiserver-operator podSelector: matchLabels: app: kube-apiserver-operator policyTypes: - Ingress ... Optional: Create a new project to confirm that your network policy objects are created successfully by running the following commands: Create a new project: USD oc new-project <project> 1 1 Replace <project> with the name for the project you are creating. Confirm that the network policy objects in the new project template exist in the new project: USD oc get networkpolicy NAME POD-SELECTOR AGE allow-from-openshift-ingress <none> 7s allow-from-same-namespace <none> 7s

Commands:
oc adm create-bootstrap-project-template -o yaml > template.yaml
oc create -f template.yaml -n openshift-config
oc edit project.config.openshift.io/cluster
apiVersion: config.openshift.io/v1 kind: Project metadata: spec: projectRequestTemplate: name: <template_name>
oc edit template <project_template> -n openshift-config
objects: - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-same-namespace spec: podSelector: {} ingress: - from: - podSelector: {} - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-openshift-ingress spec: ingress: - from: - namespaceSelector: matchLabels: network.openshift.io/policy-group: ingress podSelector: {} policyTypes: - Ingress - apiVersion: networking.k8s.io/v1 kind: NetworkPolicy metadata: name: allow-from-kube-apiserver-operator spec: ingress: - from: - namespaceSelector: matchLabels: kubernetes.io/metadata.name: openshift-kube-apiserver-operator podSelector: matchLabels: app: kube-apiserver-operator policyTypes: - Ingress
oc new-project <project> 1
oc get networkpolicy NAME POD-SELECTOR AGE allow-from-openshift-ingress <none> 7s allow-from-same-namespace <none> 7s