<p>I'm trying to deploy kafka on local k8s, then I need to connect to it by application and using offset explorer</p>
<p>so, using kubectl I created zookeeper service and deployment using this yml file</p>
<pre><code>apiVersion: v1
kind: Service
metadata:
  labels:
    app: zookeeper-service
  name: zookeeper-service
spec:
  type: NodePort
  ports:
    - name: zookeeper-port
      port: 2181
      nodePort: 30091
      targetPort: 2181
  selector:
    app: zookeeper
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: zookeeper
  name: zookeeper
spec:
  replicas: 1
  selector:
    matchLabels:
      app: zookeeper
  template:
    metadata:
      labels:
        app: zookeeper
    spec:
      containers:
        - image: bitnami/zookeeper
          imagePullPolicy: IfNotPresent
          name: zookeeper
          ports:
            - containerPort: 2181
          env:
            - name: ALLOW_PLAINTEXT_LISTENER
              value: &quot;yes&quot;
            - name: ALLOW_ANONYMOUS_LOGIN
              value: &quot;yes&quot;
</code></pre>
<p>Then, I created kafka service and deployment using this yml</p>
<pre><code>apiVersion: v1
kind: Service
metadata:
  labels:
    app: kafka-service
  name: kafka-service
spec:
  type: NodePort
  ports:
    - name: kafka-port
      port: 9092
      nodePort: 30092
      targetPort: 9092
  selector:
    app: kafka-broker
---
apiVersion: apps/v1
kind: Deployment
metadata:
  labels:
    app: kafka-broker
  name: kafka-broker
spec:
  replicas: 1
  selector:
    matchLabels:
      app: kafka-broker
  template:
    metadata:
      labels:
        app: kafka-broker
    spec:
      hostname: kafka-broker
      containers:
        - image: bitnami/kafka
          imagePullPolicy: IfNotPresent
          name: kafka-broker
          ports:
            - containerPort: 9092
          env:
            - name: KAFKA_BROKER_ID
              value: &quot;1&quot;
            - name: KAFKA_ZOOKEEPER_CONNECT
              value: &quot;zookeeper-service:2181&quot;
            - name: KAFKA_LISTENERS
              value: PLAINTEXT://localhost:9092
            - name: KAFKA_ADVERTISED_LISTENERS
              value: PLAINTEXT://localhost:9092
            # Creates a topic with one partition and one replica.
            - name: KAFKA_CREATE_TOPICS
              value: &quot;bomc:1:1&quot;
            - name: MY_POD_IP
              valueFrom:
                fieldRef:
                  fieldPath: status.podIP
            - name: ALLOW_PLAINTEXT_LISTENER
              value: &quot;yes&quot;
</code></pre>
<p>And both services and deployment created and running
<a href="https://i.stack.imgur.com/Zh5Rl.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Zh5Rl.png" alt="enter image description here" /></a></p>
<p><a href="https://i.stack.imgur.com/RekR0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/RekR0.png" alt="enter image description here" /></a></p>
<p>And I have ingress for this services</p>
<pre><code>apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: nginx-ingress
  annotations:
    kubernetes.io/ingress.class: &quot;nginx&quot;
spec:
  rules:
    - http:
        paths:
          - path: /health
            pathType: Prefix
            backend:
              service:
                name: health-app-service
                port:
                  number: 80
          - path: /actuator
            pathType: Prefix
            backend:
              service:
                name: health-app-service
                port:
                  number: 80
          - path: /jsonrpc
            pathType: Prefix
            backend:
              service:
                name: core-service
                port:
                  number: 80
          - path: /
            pathType: Prefix
            backend:
              service:
                name: kafka-service # Название вашего Kafka-сервиса
                port:
                  number: 9092 # Название порта, используемого для Kafka
          - path: /
            pathType: Prefix
            backend:
              service:
                name: kafka-service # Название вашего Kafka-сервиса
                port:
                  number: 30092 # Название порта, используемого для Kafka
          - path: /
            pathType: Prefix
            backend:
              service:
                name: kafka-service # Название вашего Kafka-сервиса
                port:
                  name: kafka-port # Название порта, используемого для Kafka
          - path: /
            pathType: Prefix
            backend:
              service:
                name: zookeeper-service
                port:
                  name: zookeeper-port
</code></pre>
<p><a href="https://i.stack.imgur.com/KZVw1.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KZVw1.png" alt="enter image description here" /></a></p>
<p>but, when I try to connect to this kafka using offset key tool, there is error connection.</p>
<p><a href="https://i.stack.imgur.com/KK2zV.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/KK2zV.png" alt="enter image description here" /></a></p>
<p><a href="https://i.stack.imgur.com/1y7bk.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/1y7bk.png" alt="enter image description here" /></a></p>
<p><a href="https://i.stack.imgur.com/D73lC.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/D73lC.png" alt="enter image description here" /></a></p>
<p>When I use localhost:30092 like a bootstrap server - error with logs:</p>
<pre><code> 12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - Starting application : Offset Explorer
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - Version : 2.3
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - Built : Jun 30, 2022
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - user.home : C:\Users\Roberto
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - user.dir : C:\Program Files\OffsetExplorer2
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - os.name : Windows 10
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - java.runtime.version : 1.8.0_232-b09
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - max memory=3586 MB
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - available processors=8
12/мар/2023 22:32:46.111 INFO  com.kafkatool.ui.MainApp - java.security.auth.login.config=null
12/мар/2023 22:32:46.121 INFO  com.kafkatool.common.ExternalDecoderManager - Finding plugins in directory C:\Program Files\OffsetExplorer2\plugins
12/мар/2023 22:32:46.121 INFO  com.kafkatool.common.ExternalDecoderManager - Found files in plugin directory, count=1
12/мар/2023 22:32:46.121 INFO  com.kafkatool.ui.MainApp - Loading user settings
12/мар/2023 22:32:46.153 INFO  com.kafkatool.ui.MainApp - Loading server group settings
12/мар/2023 22:32:46.153 INFO  com.kafkatool.ui.MainApp - Loading server connection settings
12/мар/2023 22:32:50.103 INFO  org.apache.kafka.clients.admin.AdminClientConfig - AdminClientConfig values: 
    bootstrap.servers = [localhost:30092]
    client.dns.lookup = default
    client.id = 
    connections.max.idle.ms = 300000
    metadata.max.age.ms = 300000
    metric.reporters = []
    metrics.num.samples = 2
    metrics.recording.level = INFO
    metrics.sample.window.ms = 30000
    receive.buffer.bytes = 65536
    reconnect.backoff.max.ms = 1000
    reconnect.backoff.ms = 50
    request.timeout.ms = 120000
    retries = 5
    retry.backoff.ms = 100
    sasl.client.callback.handler.class = null
    sasl.jaas.config = null
    sasl.kerberos.kinit.cmd = /usr/bin/kinit
    sasl.kerberos.min.time.before.relogin = 60000
    sasl.kerberos.service.name = null
    sasl.kerberos.ticket.renew.jitter = 0.05
    sasl.kerberos.ticket.renew.window.factor = 0.8
    sasl.login.callback.handler.class = null
    sasl.login.class = null
    sasl.login.refresh.buffer.seconds = 300
    sasl.login.refresh.min.period.seconds = 60
    sasl.login.refresh.window.factor = 0.8
    sasl.login.refresh.window.jitter = 0.05
    sasl.mechanism = GSSAPI
    security.protocol = PLAINTEXT
    security.providers = null
    send.buffer.bytes = 131072
    ssl.cipher.suites = null
    ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
    ssl.endpoint.identification.algorithm = https
    ssl.key.password = null
    ssl.keymanager.algorithm = SunX509
    ssl.keystore.location = null
    ssl.keystore.password = null
    ssl.keystore.type = JKS
    ssl.protocol = TLS
    ssl.provider = null
    ssl.secure.random.implementation = null
    ssl.trustmanager.algorithm = PKIX
    ssl.truststore.location = null
    ssl.truststore.password = null
    ssl.truststore.type = JKS

12/мар/2023 22:32:50.126 DEBUG org.apache.kafka.clients.admin.internals.AdminMetadataManager - [AdminClient clientId=adminclient-1] Setting bootstrap cluster metadata Cluster(id = null, nodes = [localhost:30092 (id: -1 rack: null)], partitions = [], controller = null).
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name connections-closed:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name connections-created:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name successful-authentication:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name successful-reauthentication:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name successful-authentication-no-reauth:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name failed-authentication:
12/мар/2023 22:32:50.188 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name failed-reauthentication:
12/мар/2023 22:32:50.198 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name reauthentication-latency:
12/мар/2023 22:32:50.199 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name bytes-sent-received:
12/мар/2023 22:32:50.199 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name bytes-sent:
12/мар/2023 22:32:50.199 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name bytes-received:
12/мар/2023 22:32:50.199 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name select-time:
12/мар/2023 22:32:50.199 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name io-time:
12/мар/2023 22:32:50.204 WARN  org.apache.kafka.clients.admin.AdminClientConfig - The configuration 'group.id' was supplied but isn't a known config.
12/мар/2023 22:32:50.204 INFO  org.apache.kafka.common.utils.AppInfoParser - Kafka version: 2.4.0
12/мар/2023 22:32:50.204 INFO  org.apache.kafka.common.utils.AppInfoParser - Kafka commitId: 77a89fcf8d7fa018
12/мар/2023 22:32:50.204 INFO  org.apache.kafka.common.utils.AppInfoParser - Kafka startTimeMs: 1678649570204
12/мар/2023 22:32:50.214 DEBUG org.apache.kafka.clients.admin.KafkaAdminClient - [AdminClient clientId=adminclient-1] Kafka admin client initialized
12/мар/2023 22:32:50.215 DEBUG org.apache.kafka.clients.admin.KafkaAdminClient - [AdminClient clientId=adminclient-1] Queueing Call(callName=listNodes, deadlineMs=1678649690215) with a timeout 120000 ms from now.
12/мар/2023 22:32:50.215 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Initiating connection to node localhost:30092 (id: -1 rack: null) using address localhost/127.0.0.1
12/мар/2023 22:32:50.228 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name node--1.bytes-sent
12/мар/2023 22:32:50.230 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name node--1.bytes-received
12/мар/2023 22:32:50.232 DEBUG org.apache.kafka.common.metrics.Metrics - Added sensor with name node--1.latency
12/мар/2023 22:32:50.232 DEBUG org.apache.kafka.common.network.Selector - [AdminClient clientId=adminclient-1] Created socket with SO_RCVBUF = 65536, SO_SNDBUF = 131072, SO_TIMEOUT = 0 to node -1
12/мар/2023 22:32:50.320 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Completed connection to node -1. Fetching API versions.
12/мар/2023 22:32:50.320 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Initiating API versions fetch from node -1.
12/мар/2023 22:32:50.376 DEBUG org.apache.kafka.common.network.Selector - [AdminClient clientId=adminclient-1] Connection with localhost/127.0.0.1 disconnected
java.io.EOFException
    at org.apache.kafka.common.network.NetworkReceive.readFrom(NetworkReceive.java:96)
    at org.apache.kafka.common.network.KafkaChannel.receive(KafkaChannel.java:424)
    at org.apache.kafka.common.network.KafkaChannel.read(KafkaChannel.java:385)
    at org.apache.kafka.common.network.Selector.attemptRead(Selector.java:651)
    at org.apache.kafka.common.network.Selector.pollSelectionKeys(Selector.java:572)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:483)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:540)
    at org.apache.kafka.clients.admin.KafkaAdminClient$AdminClientRunnable.run(KafkaAdminClient.java:1196)
    at java.lang.Thread.run(Thread.java:748)
12/мар/2023 22:33:11.787 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Node -1 disconnected.
12/мар/2023 22:33:12.766 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Initiating connection to node localhost:30092 (id: -1 rack: null) using address localhost/127.0.0.1
12/мар/2023 22:33:12.767 DEBUG org.apache.kafka.common.network.Selector - [AdminClient clientId=adminclient-1] Created socket with SO_RCVBUF = 65536, SO_SNDBUF = 131072, SO_TIMEOUT = 0 to node -1
12/мар/2023 22:33:12.767 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Completed connection to node -1. Fetching API versions.
12/мар/2023 22:33:12.767 DEBUG org.apache.kafka.clients.NetworkClient - [AdminClient clientId=adminclient-1] Initiating API versions fetch from node -1.
12/мар/2023 22:33:12.768 DEBUG org.apache.kafka.common.network.Selector - [AdminClient clientId=adminclient-1] Connection with localhost/127.0.0.1 disconnected
java.io.EOFException
    at org.apache.kafka.common.network.NetworkReceive.readFrom(NetworkReceive.java:96)
    at org.apache.kafka.common.network.KafkaChannel.receive(KafkaChannel.java:424)
    at org.apache.kafka.common.network.KafkaChannel.read(KafkaChannel.java:385)
    at org.apache.kafka.common.network.Selector.attemptRead(Selector.java:651)
    at org.apache.kafka.common.network.Selector.pollSelectionKeys(Selector.java:572)
    at org.apache.kafka.common.network.Selector.poll(Selector.java:483)
    at org.apache.kafka.clients.NetworkClient.poll(NetworkClient.java:540)
    at org.apache.kafka.clients.admin.KafkaAdminClient$AdminClientRunnable.run(KafkaAdminClient.java:1196)
    at java.lang.Thread.run(Thread.java:748)
</code></pre>

Roberto
<p>You configured the NodePort of <code>30092</code> for your kafka broker so to be able to connect to it you should use <code>&lt;node-ip&gt;:30092</code> as your bootstrap server address.</p>
<p>If you're running minikube, you can find the node ip with the <code>minikube ip</code> command.<br />
(Although you mentioned that the connection to your zookeeper at <code>localhost:30181</code> was successful so you might as well try <code>localhost:30092</code> for your kafka.)</p>
<p>Also, you don't need to port forward via <code>kubectl</code> in this case since NodePort  is exposed to the outside world anyway.</p>
<p>To debug the connection problems with Offset Explorer, enable debug logging in its settings, make an attempt to connect to your broker and check the tool's debug logs for the details of the error. The logs should be located in the same directory as the tool executable if you're running on Windows.</p>
