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 Event Streams, the required network policies will be automatically created. To review the network policies that have been applied:

Log in to your Kubernetes cluster as a cluster administrator by setting your kubectl context.
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 Streams instance. If a particular pod is not required by a given Event Streams configuration, the associated network policy will not be applied.

Note: Where a network policy exposes a port to the Event Streams Cluster operator, it is configured to allow connections from any namespace.

Kafka pod

Type	Origin	Port	Reason	Enabled in policy
TCP	REST API, REST Producer and Schema Registry pods	8091	Broker communication	Always
TCP	Kafka, Cluster operator, Entity operator, Kafka Cruise Control and Kafka Exporter pods	9091	Broker communication	Always
TCP	Anywhere (can be restricted by including `networkPolicyPeers` in the listener configuration)	9092	Kafka access for Plain listener	If the Plain listener is enabled
TCP	Anywhere (can be restricted by including `networkPolicyPeers` in the listener configuration)	9093	Kafka access for TLS listener	If the TLS listener is enabled
TCP	Anywhere (can be restricted by including `networkPolicyPeers` in the listener configuration)	9094	Kafka access for External listener	If the External listener is enabled
TCP	Anywhere	9404	Prometheus access to Kafka metrics	If metrics are enabled
TCP	Anywhere	9999	JMX access to Kafka metrics	If JMX port is exposed

Note: If required, access to listener ports can be restricted to only those pods with specific labels by including additional configuration in the Event Streams custom resource under spec.strimziOverrides.kafka.listeners.<listener>.networkPolicyPeers.

ZooKeeper pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Kafka, ZooKeeper, Cluster operator, Entity operator, Kafka Cruise Control pods	2181	ZooKeeper client connections	Always
TCP	Other ZooKeeper pods	2888	ZooKeeper follower connection to leader	Always
TCP	Other ZooKeeper pods	3888	ZooKeeper leader election	Always
TCP	Anywhere	9404	Exported Prometheus metrics	If metrics are enabled

Geo-replicator pod

Type	Origin	Port	Reason	Enabled in policy
TCP	REST API pods	8083	Geo-replicator API traffic	Always
TCP	Cluster operator and other geo-replicator pods	8083	Geo-replicator cluster traffic	Always
TCP	Anywhere	9404	Exported Prometheus metrics	If metrics are enabled

Schema registry pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	9443	External access to API	Always
TCP	Any pod in Event Streams instance	7443	TLS cluster traffic	If internal TLS is enabled
TCP	Any pod in Event Streams instance	7080	Non-TLS cluster traffic	If internal TLS is disabled

Administration UI pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	3000	External access to UI	Always

Administration server pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	9443	External access to API	Always
TCP	Any pod in Event Streams instance	7443	TLS cluster traffic	If internal TLS is enabled
TCP	Any pod in Event Streams instance	7080	Non-TLS cluster traffic	If internal TLS is disabled

REST producer server pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	9443	External access to API	Always
TCP	Any pod in Event Streams instance	7443	TLS cluster traffic	If internal TLS is enabled
TCP	Any pod in Event Streams instance	7080	Non-TLS cluster traffic	If internal TLS is disabled

Metrics collector pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	7888	Exported Prometheus metrics	Always
TCP	Any pod in Event Streams instance	7443	TLS inbound metrics traffic	If internal TLS is enabled
TCP	Any pod in Event Streams instance	7080	Non-TLS inbound metrics traffic	If internal TLS is disabled

Cluster operator pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Anywhere	8080	Exported Prometheus metrics	Always
TCP	Anywhere	8081	`EventStreams` custom resource validator	Always

Cruise Control pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Cluster operator	9090	Access to API	Always

Kafka Connect pod

Type	Origin	Port	Reason	Enabled in policy
TCP	Cluster operator and Kafka Connect pods	8083	Access to Kafka Connect REST API	Always
TCP	Anywhere	9404	Exported Prometheus metrics	If metrics are enabled

Outbound network connections (egress)

The following tables provide information about the outbound network connections (egress) initiated by pods in an Event Streams installation. If a particular pod is not required by an Event Streams configuration, the associated outbound connection is not applicable.