Chapter 6. Network policy

Procedure

1. Create a policy rule:

   1. Create a <policy-name>.yaml file where <policy-name> describes the policy rule.

   2. In the file you just created define a policy object, such as in the following example:

      kind: NetworkPolicy
      apiVersion: networking.k8s.io/v1
      metadata:
        name: <policy-name> 1
      spec:
        podSelector:
        ingress: []

      1

      Specify a name for the policy object.

2. Run the following command to create the policy object:

   $ oc create -f <policy-name>.yaml -n <project>

   In the following example, a new NetworkPolicy object is created in a project named project1:

   $ oc create -f default-deny.yaml -n project1

   Example output

   networkpolicy "default-deny" created

Procedure

1. Optional: List the current NetworkPolicy objects.

   1. If you want to list the policy objects in a specific namespace, enter the following command. Replace <namespace> with the namespace for a project.

      $ oc get networkpolicy -n <namespace>

   2. If you want to list the policy objects for the entire cluster, enter the following command:

      $ oc get networkpolicy --all-namespaces

2. Edit the NetworkPolicy object.

   1. If you saved the network policy definition in a file, edit the file and make any necessary changes, and then enter the following command. Replace <policy-file> with the name of the file containing the object definition.

      $ oc apply -f <policy-file>.yaml

   2. If you need to update the NetworkPolicy object directly, you can enter the following command. Replace <policy-name> with the name of the NetworkPolicy object and <namespace> with the name of the project where the object exists.

      $ oc edit <policy-name> -n <namespace>

3. Confirm that the NetworkPolicy object is updated. Replace <namespace> with the name of the project where the object exists.

   $ oc get networkpolicy -n <namespace> -o yaml

Procedure

1. Log in as a user with cluster-admin privileges.

2. Generate the default project template:

   $ oc adm create-bootstrap-project-template -o yaml > template.yaml

3. Use a text editor to modify the generated template.yaml file by adding objects or modifying existing objects.

4. The project template must be created in the openshift-config namespace. Load your modified template:

   $ oc create -f template.yaml -n openshift-config

5. Edit the project configuration resource using the web console or CLI.

   • Using the web console:

     1. Navigate to the Administration Cluster Settings page.
     2. Click Global Configuration to view all configuration resources.
     3. Find the entry for Project and click Edit YAML.

   • Using the CLI:

     1. Edit the project.config.openshift.io/cluster resource:

        $ oc edit project.config.openshift.io/cluster

6. 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>

7. After you save your changes, create a new project to verify that your changes were successfully applied.

Procedure

1. Edit the default template for a new project by running the following command:

   $ 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.

2. 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
   ...

3. Optional: Create a new project to confirm that your network policy objects are created successfully by running the following commands:

   1. Create a new project:

      $ oc new-project <project> 1

      1

      Replace <project> with the name for the project you are creating.

   2. Confirm that the network policy objects in the new project template exist in the new project:

      $ oc get networkpolicy
      NAME                           POD-SELECTOR   AGE
      allow-from-openshift-ingress   <none>         7s
      allow-from-same-namespace      <none>         7s

Procedure

1. Create the following NetworkPolicy objects:

   1. A policy named allow-from-openshift-ingress:

      $ cat << EOF| oc create -f -
      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
      EOF

   2. A policy named allow-from-openshift-monitoring:

      $ cat << EOF| oc create -f -
      apiVersion: networking.k8s.io/v1
      kind: NetworkPolicy
      metadata:
        name: allow-from-openshift-monitoring
      spec:
        ingress:
        - from:
          - namespaceSelector:
              matchLabels:
                network.openshift.io/policy-group: monitoring
        podSelector: {}
        policyTypes:
        - Ingress
      EOF

   3. A policy named allow-same-namespace:

      $ cat << EOF| oc create -f -
      kind: NetworkPolicy
      apiVersion: networking.k8s.io/v1
      metadata:
        name: allow-same-namespace
      spec:
        podSelector:
        ingress:
        - from:
          - podSelector: {}
      EOF

2. If the default Ingress Controller configuration has the spec.endpointPublishingStrategy: HostNetwork value set, you must apply a label to the default OpenShift Container Platform namespace to allow network traffic between the Ingress Controller and the project:

   1. Determine if your default Ingress Controller uses the HostNetwork endpoint publishing strategy:

      $ oc get --namespace openshift-ingress-operator ingresscontrollers/default \
        --output jsonpath='{.status.endpointPublishingStrategy.type}'

   2. If the previous command reports the endpoint publishing strategy as HostNetwork, set a label on the default namespace:

      $ oc label namespace default 'network.openshift.io/policy-group=ingress'

3. Confirm that the NetworkPolicy object exists in your current project by running the following command:

   $ oc get networkpolicy <policy-name> -o yaml

   In the following example, the allow-from-openshift-ingress NetworkPolicy object is displayed:

   $ oc get -n project1 networkpolicy allow-from-openshift-ingress -o yaml

   Example output

   apiVersion: networking.k8s.io/v1
   kind: NetworkPolicy
   metadata:
     name: allow-from-openshift-ingress
     namespace: project1
   spec:
     ingress:
     - from:
       - namespaceSelector:
           matchLabels:
             network.openshift.io/policy-group: ingress
     podSelector: {}
     policyTypes:
     - Ingress