MQTT Proxy Error: No LoginModules configured for ConfluentKafkaMqtt

Clients
1

Hi there,

(I put this topic here under “Clients”, because I don’t know where else to put it.)

I want to configure a MQTT-Proxy via a Docker container together with the other Confluent stuff (broker, rest-proxy, etc.). The relevant part in my docker-compose.yml looks like this:

  kafka-mqtt:
    image: confluentinc/cp-kafka-mqtt:latest
    depends_on:
      - broker
    ports:
      - "1883:1883"
    environment:
      KAFKA_MQTT_BOOTSTRAP_SERVERS: PLAINTEXT://broker:29092
      KAFKA_MQTT_TOPIC_REGEX_LIST: test:test
      KAFKA_MQTT_LISTENERS: 0.0.0.0:1883
      KAFKA_MQTT_CONFLUENT_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_MQTT_LISTENERS_SECURITY_PROTOCOL: SASL_PLAINTEXT
      KAFKA_OPTS: "-Djava.security.auth.login.config=/etc/conf/jaas.conf"
    volumes:
      - ./configs:/etc/conf

In addition to that I have a jaas.conf:

ConfluentKafkaMqtt {
  io.confluent.mqtt.protocol.security.PropertyFileLoginModule required
    file="/etc/conf/credentials.txt";
};

As well as a (very secure) credentials.txt:

test=test

My setup has worked before I added the security/jaas things, so it must be something with it.
When trying to connect to MQTT Proxy the connection is refused. The logs for the kafka-container give me the following error:

javax.security.auth.login.LoginException: No LoginModules configured for ConfluentKafkaMqtt

So it doesn’t seem to find my jaas.conf. (?)
It is in the container however - I checked that. So what’s the problem here?
Help would be very much appreciated :slight_smile:

2

hey @massi1008 welcome :slight_smile:

could you share your docker-compose.yml?

and did you check?
https://docs.confluent.io/platform/current/kafka-mqtt/security-settings.html#between-mqtt-and-ak

best,
michael

3

Hi Michael,

here is the entire long .yml:

---
version: '2'
services:
  zookeeper:
    image: confluentinc/cp-zookeeper:6.2.0
    hostname: zookeeper
    container_name: zookeeper
    ports:
      - "2181:2181"
    environment:
      ZOOKEEPER_CLIENT_PORT: 2181
      ZOOKEEPER_TICK_TIME: 2000

  broker:
    image: confluentinc/cp-server:6.2.0
    hostname: broker
    container_name: broker
    depends_on:
      - zookeeper
    ports:
      - "9092:9092"
      - "9101:9101"
    environment:
      KAFKA_BROKER_ID: 1
      KAFKA_ZOOKEEPER_CONNECT: 'zookeeper:2181'
      KAFKA_LISTENER_SECURITY_PROTOCOL_MAP: PLAINTEXT:PLAINTEXT,PLAINTEXT_HOST:PLAINTEXT
      KAFKA_ADVERTISED_LISTENERS: PLAINTEXT://broker:29092,PLAINTEXT_HOST://localhost:9092
      KAFKA_METRIC_REPORTERS: io.confluent.metrics.reporter.ConfluentMetricsReporter
      KAFKA_OFFSETS_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_GROUP_INITIAL_REBALANCE_DELAY_MS: 0
      KAFKA_CONFLUENT_LICENSE_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_CONFLUENT_BALANCER_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_TRANSACTION_STATE_LOG_MIN_ISR: 1
      KAFKA_TRANSACTION_STATE_LOG_REPLICATION_FACTOR: 1
      KAFKA_JMX_PORT: 9101
      KAFKA_JMX_HOSTNAME: localhost
      KAFKA_CONFLUENT_SCHEMA_REGISTRY_URL: http://schema-registry:8081
      CONFLUENT_METRICS_REPORTER_BOOTSTRAP_SERVERS: broker:29092
      CONFLUENT_METRICS_REPORTER_TOPIC_REPLICAS: 1
      CONFLUENT_METRICS_ENABLE: 'true'
      CONFLUENT_SUPPORT_CUSTOMER_ID: 'anonymous'

  schema-registry:
    image: confluentinc/cp-schema-registry:6.2.0
    hostname: schema-registry
    container_name: schema-registry
    depends_on:
      - broker
    ports:
      - "8081:8081"
    environment:
      SCHEMA_REGISTRY_HOST_NAME: schema-registry
      SCHEMA_REGISTRY_KAFKASTORE_BOOTSTRAP_SERVERS: 'broker:29092'
      SCHEMA_REGISTRY_LISTENERS: http://0.0.0.0:8081

  connect:
    image: cnfldemos/cp-server-connect-datagen:0.5.0-6.2.0
    hostname: connect
    container_name: connect
    depends_on:
      - broker
      - schema-registry
    ports:
      - "8083:8083"
    environment:
      CONNECT_BOOTSTRAP_SERVERS: 'broker:29092'
      CONNECT_REST_ADVERTISED_HOST_NAME: connect
      CONNECT_REST_PORT: 8083
      CONNECT_GROUP_ID: compose-connect-group
      CONNECT_CONFIG_STORAGE_TOPIC: docker-connect-configs
      CONNECT_CONFIG_STORAGE_REPLICATION_FACTOR: 1
      CONNECT_OFFSET_FLUSH_INTERVAL_MS: 10000
      CONNECT_OFFSET_STORAGE_TOPIC: docker-connect-offsets
      CONNECT_OFFSET_STORAGE_REPLICATION_FACTOR: 1
      CONNECT_STATUS_STORAGE_TOPIC: docker-connect-status
      CONNECT_STATUS_STORAGE_REPLICATION_FACTOR: 1
      CONNECT_KEY_CONVERTER: org.apache.kafka.connect.storage.StringConverter
      CONNECT_VALUE_CONVERTER: io.confluent.connect.avro.AvroConverter
      CONNECT_VALUE_CONVERTER_SCHEMA_REGISTRY_URL: http://schema-registry:8081
      # CLASSPATH required due to CC-2422
      CLASSPATH: /usr/share/java/monitoring-interceptors/monitoring-interceptors-6.2.0.jar
      CONNECT_PRODUCER_INTERCEPTOR_CLASSES: "io.confluent.monitoring.clients.interceptor.MonitoringProducerInterceptor"
      CONNECT_CONSUMER_INTERCEPTOR_CLASSES: "io.confluent.monitoring.clients.interceptor.MonitoringConsumerInterceptor"
      CONNECT_PLUGIN_PATH: "/usr/share/java,/usr/share/confluent-hub-components"
      CONNECT_LOG4J_LOGGERS: org.apache.zookeeper=ERROR,org.I0Itec.zkclient=ERROR,org.reflections=ERROR
    command:
      - bash
      - -c
      - |
        confluent-hub install --no-prompt neo4j/kafka-connect-neo4j:1.0.9 && \
        confluent-hub install confluentinc/kafka-connect-mqtt:1.4.1 && \
        confluent-hub install --no-prompt confluentinc/kafka-connect-datagen:latest
        /etc/confluent/docker/run &
        sleep infinity

  control-center:
    image: confluentinc/cp-enterprise-control-center:6.2.0
    hostname: control-center
    container_name: control-center
    depends_on:
      - broker
      - schema-registry
      - connect
      - mqtt
      #- ksqldb-server
    ports:
      - "9021:9021"
    environment:
      CONTROL_CENTER_BOOTSTRAP_SERVERS: 'broker:29092'
      CONTROL_CENTER_CONNECT_CLUSTER: 'connect:8083'
#      CONTROL_CENTER_KSQL_KSQLDB1_URL: "http://ksqldb-server:8088"
#      CONTROL_CENTER_KSQL_KSQLDB1_ADVERTISED_URL: "http://localhost:8088"
      CONTROL_CENTER_SCHEMA_REGISTRY_URL: "http://schema-registry:8081"
      CONTROL_CENTER_REPLICATION_FACTOR: 1
      CONTROL_CENTER_INTERNAL_TOPICS_PARTITIONS: 1
      CONTROL_CENTER_MONITORING_INTERCEPTOR_TOPIC_PARTITIONS: 1
      CONFLUENT_METRICS_TOPIC_REPLICATION: 1
      PORT: 9021
      

  rest-proxy:
    image: confluentinc/cp-kafka-rest:6.2.0
    depends_on:
      - broker
      - schema-registry
    ports:
      - 8082:8082
    hostname: rest-proxy
    container_name: rest-proxy
    environment:
      KAFKA_REST_HOST_NAME: rest-proxy
      KAFKA_REST_BOOTSTRAP_SERVERS: 'broker:29092'
      KAFKA_REST_LISTENERS: "http://0.0.0.0:8082"
      KAFKA_REST_SCHEMA_REGISTRY_URL: 'http://schema-registry:8081'

  kafka-mqtt:
    image: confluentinc/cp-kafka-mqtt:latest
    depends_on:
      - broker
    ports:
      - "1883:1883"
    environment:
      KAFKA_MQTT_BOOTSTRAP_SERVERS: PLAINTEXT://broker:29092
      KAFKA_MQTT_TOPIC_REGEX_LIST: test:test
      KAFKA_MQTT_LISTENERS: 0.0.0.0:1883
      KAFKA_MQTT_CONFLUENT_TOPIC_REPLICATION_FACTOR: 1
      KAFKA_MQTT_LISTENERS_SECURITY_PROTOCOL: SASL_PLAINTEXT
      KAFKA_OPTS: "-Djava.security.auth.login.config=/etc/conf/jaas.conf"
    volumes:
      - ./configs:/etc/conf

Regarding the link your send: This is authentification between MQTT-Proxy and Kafka-Broker. This is not what I’m looking for. Is this needed?

4

ah sorry my mistake.
will check by myself and come back to you :slight_smile:

5

HELLO, I FINALLY FOUND THE PROBLEM!

The jaas and credential files were not the problem. They were fine as is. The problem was this environment variable here:

KAFKA_OPTS: "-Djava.security.auth.login.config=/etc/conf/jaas.conf"

The “KAFKA_OPTS” isn’t recognized! It should be like this:

KAFKA_MQTT_OPTS:" -Djava.security.auth.login.config=/etc/confluent-kafka-mqtt/jaas.conf"

The “MQTT” was missing.
(I also changed the config folder, because the docs say so. That wasn’t the problem however.)

The damn documentation was just wrong…

Anyway, I’ll send an email to correct to docs.

1 Like
6

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.