Kafka "Login module not specified in JAAS config"

Question

I have a problem communicating with Kafka secured with sasl using console scripts. Kafka is secured with sasl, listener is SASL_PLAINTEXT and mechanism is PLAIN.

What I did: I tried listing some data using one of kafka scripts:

bin/kafka-consumer-groups.sh --bootstrap-server (address) --list

However I get

WARN Bootstrap broker (address) disconnected (org.apache.kafka.clients.NetworkClient)

and command fails, which is understandable because it's secured with sasl.

So I tried how to add client username/password to that command. First, I tried to run kafka-console-consumer script, I used --command-config to add necessary file. I quickly discovered that I can't add jaas file directly and I needed to use .properties file, so I did.

My properties file(keep in mind that brackets indicate "censored" data, I can't put all real data here):

bootstrap.servers=(address)
zookeeper.connect=127.0.0.1:2181
zookeeper.connection.timeout.ms=6000
sasl.jaas.config=(path)/consumer_jaas.conf
security.protocol=SASL_PLAINTEXT
sasl.mechanism=PLAIN
group.id=(group)

My jaas file:

KafkaClient {
    org.apache.kafka.common.security.plain.PlainLoginModule required
    username=(username)
    password=(password);
};

This jaas file works in my standard java applications.

However, when I'm trying to run either kafka-consumer-groups script or kafka-console-consumer, I get this error:

Exception in thread "main" org.apache.kafka.common.KafkaException: java.lang.IllegalArgumentException: Login module not specified in JAAS config
at org.apache.kafka.common.network.SaslChannelBuilder.configure(SaslChannelBuilder.java:94)
at org.apache.kafka.common.network.ChannelBuilders.create(ChannelBuilders.java:93)
at org.apache.kafka.common.network.ChannelBuilders.clientChannelBuilder(ChannelBuilders.java:51)
at org.apache.kafka.clients.ClientUtils.createChannelBuilder(ClientUtils.java:84)
at kafka.admin.AdminClient$.create(AdminClient.scala:229)
at kafka.admin.AdminClient$.create(AdminClient.scala:223)
at kafka.admin.AdminClient$.create(AdminClient.scala:221)
at kafka.admin.ConsumerGroupCommand$KafkaConsumerGroupService.createAdminClient(ConsumerGroupCommand.scala:454)
at kafka.admin.ConsumerGroupCommand$KafkaConsumerGroupService.<init>(ConsumerGroupCommand.scala:389)
at kafka.admin.ConsumerGroupCommand$.main(ConsumerGroupCommand.scala:65)
at kafka.admin.ConsumerGroupCommand.main(ConsumerGroupCommand.scala)
Caused by: java.lang.IllegalArgumentException: Login module not specified in JAAS config
at org.apache.kafka.common.security.JaasConfig.<init>(JaasConfig.java:68)
at org.apache.kafka.common.security.JaasUtils.jaasConfig(JaasUtils.java:59)
at org.apache.kafka.common.network.SaslChannelBuilder.configure(SaslChannelBuilder.java:85)

This jaas file is a direct copy of a file that I'm using in java app that communicates with kafka and it works, however here, using console tools, it just doesn't work. I tried searching for a solution but I can't find anything useful.

Can anyone help me with this?

Answer 1

There are 2 ways to provide the JAAS configuration to the Kafka clients.

• Via the client property: sasl.jaas.config. In that case you set it to the actual JAAS configuration entry. For example, your configuration file becomes:

  bootstrap.servers=(address)
  zookeeper.connect=127.0.0.1:2181
  zookeeper.connection.timeout.ms=6000
  sasl.jaas.config=org.apache.kafka.common.security.plain.PlainLoginModule required username="(username)" password="(password)";
  security.protocol=SASL_PLAINTEXT
  sasl.mechanism=PLAIN
  group.id=(group)
  

  As you've already figured out, you can use --command-config to pass a properties file to kafka-consumer-groups.sh.

• Via the Java property: java.security.auth.login.config. In this case, you set it to the path of your JAAS file. Also if you set it in KAFKA_OPTS, kafka-consumer-groups.sh will pick it up automatically.

  export KAFKA_OPTS="-Djava.security.auth.login.config=(path)/consumer_jaas.conf"