Kerberos SASL authentication using node-rdkafka - node.js

Question

I am having an issue trying to connect to a Kafka instance that uses Kerberos SASL authentication using the node-rdkafka npm module, and the lack of documentation and examples out there are making things very difficult to solve the issue. I am using the Alpine setup found here
to pull in all of the necessary librdkafka and node-rdkafka dependencies and create an image. I am trying to run my container with the following configuration object for a node-rdkafka producer to connect to Kafka instance:
'debug': 'all',
'client.id': 'kafka',
'metadata.broker.list': KAFKA_DOMAINS,
'sasl.kerberos.principal': '<id>#<REALM>',
'sasl.kerberos.keytab': '/path/to/<id>.keytab',
'sasl.kerberos.service.name': 'kafka',
'security.protocol': 'sasl_plaintext',
'sasl.kerberos.kinit.cmd': 'kinit -kt /path/to/<id>.keytab <id>#<REALM>',
'dr_cb': true,
'event_cb': true
When I try to run the container, it hangs up and then throws the following error:
[2019-02-05T17:09:59.637Z] ERROR: kafka/7 on 95c927d11411: broker transport failure (err.code=-195)
Error: Local: Broker transport failure
at Function.createLibrdkafkaError [as create] (/opt/rdkafka/node_modules/node-rdkafka/lib/error.js:261:10)
at /opt/rdkafka/node_modules/node-rdkafka/lib/client.js:339:28
Here is the output from the features and libkafkaversion log statements:
[2019-02-05T17:09:29.519Z] INFO: kafka/7 on 95c927d11411:
[ 'gzip',
'snappy',
'ssl',
'sasl',
'regex',
'lz4',
'sasl_gssapi',
'sasl_plain',
'sasl_scram',
'plugins' ]
[2019-02-05T17:09:29.521Z] INFO: kafka/7 on 95c927d11411: 0.11.5
What am I missing that I am unable to connect? Am I missing some environment variables? I know that the Java implementation of librdkafka involves passing the REALM, KDC_HOST, and some .conf files (krb5 and jaas). Do I have to set up some kind of environment variable? I can find no examples or solutions.