Kafka Security & the Confluent Platform¶
The Schema Registry and REST Proxy do not currently support Kafka’s security features. This is planned for a future release. However, you can have a secured Kafka cluster which coexists with
PLAINTEXT clients such as the Schema Registry and REST proxy.
Kafka 0.9.0 brokers can now listen on multiple ports, where each port supports the configured protocol. This can be done by adding a
PLAINTEXT port to listeners, but care has to be taken to restrict access to this port to trusted clients only. Network segmentation and/or authorization ACLs can be used to restrict access to trusted IPs in such cases.
Here is an example broker config with both
SSL ports enabled:
When connecting to the
PLAINTEXT port, you need to set
PLAINTEXT in the producer and consumer property. The documentation on adding security to a running cluster can provide additional insight on broker support for multiple security protocols as well as instructions for adding security to a running cluster.
Here are a few additional observations/strategies to keep in mind when securing your Kafka cluster along with Kafka-REST and Schema Registry:
- With respect to Kafka ACLs
One potential option is to only allow access to the
PLAINTEXT port for internal apps/tools via network segmentation, and then assume that the ANONYMOUS user is always an internal user. Another option is to take advantage of the fact that Kafka ACLS can also be applied on a per-host basis. For details, see the reference to kafka-acls.sh in the section on ACLs and authorization.
- Schema Registry
Relatively few services need access to the Schema Registry, and they are likely internal, so you can restrict access via firewall rules and/or network segmentation.
- Kafka REST Proxy
If your REST proxy needs to be visible to the external world, it’s likely you will want to encrypt payloads between the REST proxy and the external world. Since the REST proxy doesn’t support this directly, a possible solution is to set up an HTTPS proxy between the REST proxy and the external world.