When running in hybrid mode with shared keys, the Data Plane does not connect to the Control Plane

After setting up a hybrid instance, using shared certificates, the data planes do not get the configuration updated from the control plane. Checking the data plane logs, there is an error for the TLS handshake failing (tls handshake failed: certificate host mismatch).

connection to control plane wss://10.0.10.1:8005/v1/outlet?node_id=4a8198f6-494e-4a94-8a3c-a34b8705c2da&node_hostname=dataplane-kong-enterprise-fda26afc40-46ed2&node_version=3.14.0.0-enterprise-edition broken: tls handshake failed: certificate host mismatch (retrying after 10 seconds), context: ngx.timer

The shared certificates were generated using openssl and not the kong hybrid gen_cert command.

In hybrid shared mode, the certificates must have a common name of kong_clustering. If the certificates use a different common name, then you will see the host mismatch error.

You can generate certificates with the correct format with an openssl command like this:

openssl req -new -x509 -nodes -newkey ec:<(openssl ecparam -name secp384r1) \
  -keyout /tmp/cluster.key -out /tmp/cluster.crt \
  -days 1095 -subj "/CN=kong_clustering"