Network policies

Inbound network connections (ingress)

Network policies are used to control inbound connections into pods. These connections can be from pods within the cluster, or from external sources.

When you install an instance of the Event Manager, the required network policies will be automatically created unless they are disabled through configuration options. To review the network policies that have been applied:

1. Log in to your Kubernetes cluster as a cluster administrator by setting your kubectl context.

2. Run the following command to display the installed network policies for a specific namespace:\

   kubectl get netpol -n <namespace>
   

The following tables provide information about the network policies that are applicable to each pod within the Event Manager instance. Information about how to stop deployment of the network policies are included in the notes after each table.

Note: Not all networking solutions support network policies. Creating NetworkPolicy resources on clusters with solutions that do not support policies has no effect on restricting traffic.

Event Endpoint Management operator pod

Note: By default a network policy is created that restricts traffic to port 8443, but does not restrict where that traffic originates from. For increased security, you can disable this auto-generated network policy and create a more secure network policy that restricts ingress traffic to the operator pod’s port to be only from the Kubernetes API server.

To delete the network policy of the Event Endpoint Management operator:

• On Kubernetes platforms other than OpenShift: install the Helm chart by specifying --set deployOperatorNetworkPolicy=false.

• On OpenShift Container Platform: modify the subscription that was used to install the operator and set the DEPLOY_OPERATOR_NETWORK_POLICY environment variable to false. Do this after the initial installation of the operator.

  By using the OpenShift console:

  1. Log in to the OpenShift Container Platform web console using your login credentials.
  2. Expand Home in the navigation menu and click Search.
  3. From the Project list, select the namespace where you installed the operator.
  4. From the Resources list, select Subscription.
  5. From the results, select your Event Endpoint Management subscription by clicking its name.
  6. Click the YAML tab.

  7. Scroll to the spec section of YAML file, and add the DEPLOY_OPERATOR_NETWORK_POLICY environment variable as follows:

     spec:
       config:
         env:
           - name: DEPLOY_OPERATOR_NETWORK_POLICY
             value: 'false'
     

  8. Click Save.

  By using the command line:

  1. Find the name of your subscription by running the following command. Replace <OPERATOR_NAMESPACE> with the namespace where you installed the operator.

     kubectl get subscription -n <OPERATOR_NAMESPACE>
     

  2. Edit your subscription by using the kubectl edit subscription <SUBSCRIPTION_NAME> -n <OPERATOR_NAMESPACE> command, and update the spec section to include the DEPLOY_OPERATOR_NETWORK_POLICY environment variable.

     apiVersion: operators.coreos.com/v1alpha1
     kind: Subscription
     metadata:
       name: eem
       namespace: my-eem-ns
     spec:
       channel: v11.3
       installPlanApproval: Automatic
       name: ibm-eventendpointmanagement
       source: eem-operator-catalog
       sourceNamespace: openshift-marketplace
       config:
         env:
           - name: DEPLOY_OPERATOR_NETWORK_POLICY
             value: 'false'
     

Note: On OpenShift Container Platform, if the cluster uses OpenShift software-defined networking (SDN) in its default network isolation mode, or OVN-Kubernetes as the Cluster Network Interface (CNI) plugin, you can create a more secure network policy that restricts ingress communication to the host-network pods by using a namespace matchLabel set to policy-group.network.openshift.io/host-network: ''

The following is an example network policy that provides this increased security:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-apiserver-eem-webhook
spec:
  podSelector:
    matchLabels:
      app.kubernetes.io/instance: ibm-eem-operator
      app.kubernetes.io/name: ibm-event-endpoint-management
  policyTypes:
  ingress:
    - ports:
        - protocol: TCP
          port: 8443
      from:
        - namespaceSelector:
            matchLabels:
              policy-group.network.openshift.io/host-network: ''
  policyTypes:
    - Ingress

If you are using a different CNI plugin that supports network policies, it might be possible to create a network policy that permits traffic from the Kubernetes API server by allowing access to one or more Classless Inter-Domain Routing (CIDR) blocks. For example, if you are using Calico, you can specify CIDR blocks for the IPv4 addresses of the master nodes (ipv4IPIPTunnelAddr). You can view CIDR blocks by running and inspecting the output from kubectl cluster-info dump.

The following is an example network policy that allows access to a CIDR block:

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: allow-apiserver-eem-webhook
spec:
  ingress:
  - from:
    - ipBlock:
        cidr: 192.168.78.128/32
    ports:
    - port: 8443
      protocol: TCP
  podSelector:
    matchLabels:
      app.kubernetes.io/instance: ibm-eem-operator
      app.kubernetes.io/name: ibm-event-endpoint-management
  policyTypes:
  - Ingress

Note: On clusters where network policies are not supported, use an alternative configuration specific to your CNI plugin.

Event Manager pod

Note: To stop the automatic deployment of the instance’s network policy, set the spec.deployNetworkPolicies option for the instance to false.

Event Gateway pod

Note: To stop the automatic deployment of the instance’s network policy, set the spec.deployNetworkPolicies option for the instance to false.

Considerations for ingress

Consider the use of a deny-all-ingress network policy to limit communication with all pods in a namespace to only those communications specifically allowed in network policies. A deny-all network policy is not created by default as it would interfere with other applications installed in the namespace that do not have the required network policies set to allow inbound communications.

To create a deny-all-ingress network policy, apply the following YAML to your cluster in the namespaces where you installed Event Endpoint Management.

apiVersion: networking.k8s.io/v1
kind: NetworkPolicy
metadata:
  name: default-deny-ingress
spec:
  podSelector: {}
  policyTypes:
  - Ingress

Outbound network connections (egress)

The following tables provide information about the outbound network connections (egress) initiated by pods in an Event Endpoint Management installation.

Note: Egress policies are not added by default. You must configure the egress policies based on your requirements.

Event Endpoint Management operator pod

Event Manager pod

Event Gateway pod