Unable to use kafka-ui with locally running kafka cluster at localhost:9092

[beachwood23]

Issue submitter TODO list

• I've looked up my issue in FAQ
• I've searched for an already existing issues here
• I've tried running main-labeled docker image and the issue still persists there
• I'm running a supported version of the application which is listed here

Describe the bug (actual behavior)

When I run:

docker pull provectuslabs/kafka-ui
docker run -it -p 8080:8080 -e DYNAMIC_CONFIG_ENABLED=true provectuslabs/kafka-ui

I see:

 docker run -it -p 8080:8080 -e DYNAMIC_CONFIG_ENABLED=true provectuslabs/kafka-ui
Standard Commons Logging discovery in action with spring-jcl: please remove commons-logging.jar from classpath in order to avoid potential conflicts
 _   _ ___    __             _                _          _  __      __ _
| | | |_ _|  / _|___ _ _    /_\  _ __ __ _ __| |_  ___  | |/ /__ _ / _| |_____
| |_| || |  |  _/ _ | '_|  / _ \| '_ / _` / _| ' \/ -_) | ' </ _` |  _| / / _`|
 \___/|___| |_| \___|_|   /_/ \_| .__\__,_\__|_||_\___| |_|\_\__,_|_| |_\_\__,|
                                 |_|

2025-02-03 22:50:38,515 WARN  [main] c.p.k.u.u.DynamicConfigOperations: Dynamic config file /etc/kafkaui/dynamic_config.yaml doesnt exist or not readable
2025-02-03 22:50:38,526 INFO  [main] c.p.k.u.KafkaUiApplication: Starting KafkaUiApplication using Java 17.0.6 with PID 1 (/kafka-ui-api.jar started by kafkaui in /)
2025-02-03 22:50:38,526 DEBUG [main] c.p.k.u.KafkaUiApplication: Running with Spring Boot v3.1.3, Spring v6.0.11
2025-02-03 22:50:38,527 INFO  [main] c.p.k.u.KafkaUiApplication: No active profile set, falling back to 1 default profile: "default"
2025-02-03 22:50:40,692 INFO  [main] o.s.b.a.s.r.ReactiveUserDetailsServiceAutoConfiguration:

Using generated security password: 8a4e69ab-3617-41ec-b42b-66eac047ec75

2025-02-03 22:50:40,808 WARN  [main] c.p.k.u.c.a.DisabledAuthSecurityConfig: Authentication is disabled. Access will be unrestricted.
2025-02-03 22:50:40,919 INFO  [main] o.s.b.a.e.w.EndpointLinksResolver: Exposing 3 endpoint(s) beneath base path '/actuator'
2025-02-03 22:50:41,323 INFO  [main] o.s.b.w.e.n.NettyWebServer: Netty started on port 8080
2025-02-03 22:50:41,337 INFO  [main] c.p.k.u.KafkaUiApplication: Started KafkaUiApplication in 3.334 seconds (process running for 3.833)
2025-02-03 22:50:53,480 INFO  [parallel-2] audit: {"timestamp":"2025-02-03T22:50:53.465726420Z","username":"Unknown","resources":[],"operation":"getCurrentConfig","result":{"success":true}}
2025-02-03 22:51:10,242 INFO  [reactor-http-nio-4] o.a.k.c.a.AdminClientConfig: AdminClientConfig values:
        auto.include.jmx.reporter = true
        bootstrap.servers = [localhost:9092]
        client.dns.lookup = use_all_dns_ips
        client.id = kui-admin-client-validation-1738623070231
        connections.max.idle.ms = 300000
        default.api.timeout.ms = 5000
        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 = 5000
        retries = 1
        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.connect.timeout.ms = null
        sasl.login.read.timeout.ms = 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.login.retry.backoff.max.ms = 10000
        sasl.login.retry.backoff.ms = 100
        sasl.mechanism = GSSAPI
        sasl.oauthbearer.clock.skew.seconds = 30
        sasl.oauthbearer.expected.audience = null
        sasl.oauthbearer.expected.issuer = null
        sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
        sasl.oauthbearer.jwks.endpoint.url = null
        sasl.oauthbearer.scope.claim.name = scope
        sasl.oauthbearer.sub.claim.name = sub
        sasl.oauthbearer.token.endpoint.url = null
        security.protocol = PLAINTEXT
        security.providers = null
        send.buffer.bytes = 131072
        socket.connection.setup.timeout.max.ms = 30000
        socket.connection.setup.timeout.ms = 10000
        ssl.cipher.suites = null
        ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
        ssl.endpoint.identification.algorithm = https
        ssl.engine.factory.class = null
        ssl.key.password = null
        ssl.keymanager.algorithm = SunX509
        ssl.keystore.certificate.chain = null
        ssl.keystore.key = null
        ssl.keystore.location = null
        ssl.keystore.password = null
        ssl.keystore.type = JKS
        ssl.protocol = TLSv1.3
        ssl.provider = null
        ssl.secure.random.implementation = null
        ssl.trustmanager.algorithm = PKIX
        ssl.truststore.certificates = null
        ssl.truststore.location = null
        ssl.truststore.password = null
        ssl.truststore.type = JKS

2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka version: 3.5.0
2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka commitId: c97b88d5db4de28d
2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka startTimeMs: 1738623070338
2025-02-03 22:51:10,353 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,354 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,458 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,458 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,560 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,560 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,864 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,864 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:11,272 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:11,272 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:12,190 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:12,190 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:13,316 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:13,317 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:14,234 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:14,235 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:15,151 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:15,152 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:15,346 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.i.AdminMetadataManager: [AdminClient clientId=kui-admin-client-validation-1738623070231] Metadata update failed
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: fetchMetadata
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.u.AppInfoParser: App info kafka.admin.client for kui-admin-client-validation-1738623070231 unregistered
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.i.AdminMetadataManager: [AdminClient clientId=kui-admin-client-validation-1738623070231] Metadata update failed
org.apache.kafka.common.errors.TimeoutException: The AdminClient thread has exited. Call: fetchMetadata
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.KafkaAdminClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Timed out 1 remaining operation(s) during close.
2025-02-03 22:51:15,379 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Metrics scheduler closed
2025-02-03 22:51:15,380 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Closing reporter org.apache.kafka.common.metrics.JmxReporter
2025-02-03 22:51:15,380 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Metrics reporters closed
2025-02-03 22:51:15,380 ERROR [parallel-3] c.p.k.u.u.KafkaServicesValidation: Error connecting to cluster
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: listTopics
2025-02-03 22:51:15,385 INFO  [parallel-3] audit: {"timestamp":"2025-02-03T22:51:15.384400375Z","username":"Unknown","resources":[],"operation":"validateConfig","result":{"success":true}}

I have a local Kafka cluster running at localhost:9092. This is using the default Kafka docker image from here: https://hub.docker.com/layers/apache/kafka/latest/images/sha256-515a27c1fef65dab7ea736d27369d866e2bcb0ab7e28273541e7280842fe0128

Using the standard kafka bin scripts, I can do:

bin/kafka-topics.sh --list --bootstrap-server localhost:9092

And get back:

test-topic1
test-topic2

And I can even create events / other topics.

Is there some special config to do in Kafka-UI to make this work against a localhost? Thank you!

Expected behavior

I expect to be able to connect Kafka-UI to a cluster running at localhost:9092.

Your installation details

Ran docker pull provectuslabs/kafka-ui, running latest docker image version
provectus/kafka-ui@83b5a60

Steps to reproduce

When I run:

docker pull provectuslabs/kafka-ui
docker run -it -p 8080:8080 -e DYNAMIC_CONFIG_ENABLED=true provectuslabs/kafka-ui

I see:

 docker run -it -p 8080:8080 -e DYNAMIC_CONFIG_ENABLED=true provectuslabs/kafka-ui
Standard Commons Logging discovery in action with spring-jcl: please remove commons-logging.jar from classpath in order to avoid potential conflicts
 _   _ ___    __             _                _          _  __      __ _
| | | |_ _|  / _|___ _ _    /_\  _ __ __ _ __| |_  ___  | |/ /__ _ / _| |_____
| |_| || |  |  _/ _ | '_|  / _ \| '_ / _` / _| ' \/ -_) | ' </ _` |  _| / / _`|
 \___/|___| |_| \___|_|   /_/ \_| .__\__,_\__|_||_\___| |_|\_\__,_|_| |_\_\__,|
                                 |_|

2025-02-03 22:50:38,515 WARN  [main] c.p.k.u.u.DynamicConfigOperations: Dynamic config file /etc/kafkaui/dynamic_config.yaml doesnt exist or not readable
2025-02-03 22:50:38,526 INFO  [main] c.p.k.u.KafkaUiApplication: Starting KafkaUiApplication using Java 17.0.6 with PID 1 (/kafka-ui-api.jar started by kafkaui in /)
2025-02-03 22:50:38,526 DEBUG [main] c.p.k.u.KafkaUiApplication: Running with Spring Boot v3.1.3, Spring v6.0.11
2025-02-03 22:50:38,527 INFO  [main] c.p.k.u.KafkaUiApplication: No active profile set, falling back to 1 default profile: "default"
2025-02-03 22:50:40,692 INFO  [main] o.s.b.a.s.r.ReactiveUserDetailsServiceAutoConfiguration:

Using generated security password: 8a4e69ab-3617-41ec-b42b-66eac047ec75

2025-02-03 22:50:40,808 WARN  [main] c.p.k.u.c.a.DisabledAuthSecurityConfig: Authentication is disabled. Access will be unrestricted.
2025-02-03 22:50:40,919 INFO  [main] o.s.b.a.e.w.EndpointLinksResolver: Exposing 3 endpoint(s) beneath base path '/actuator'
2025-02-03 22:50:41,323 INFO  [main] o.s.b.w.e.n.NettyWebServer: Netty started on port 8080
2025-02-03 22:50:41,337 INFO  [main] c.p.k.u.KafkaUiApplication: Started KafkaUiApplication in 3.334 seconds (process running for 3.833)
2025-02-03 22:50:53,480 INFO  [parallel-2] audit: {"timestamp":"2025-02-03T22:50:53.465726420Z","username":"Unknown","resources":[],"operation":"getCurrentConfig","result":{"success":true}}
2025-02-03 22:51:10,242 INFO  [reactor-http-nio-4] o.a.k.c.a.AdminClientConfig: AdminClientConfig values:
        auto.include.jmx.reporter = true
        bootstrap.servers = [localhost:9092]
        client.dns.lookup = use_all_dns_ips
        client.id = kui-admin-client-validation-1738623070231
        connections.max.idle.ms = 300000
        default.api.timeout.ms = 5000
        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 = 5000
        retries = 1
        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.connect.timeout.ms = null
        sasl.login.read.timeout.ms = 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.login.retry.backoff.max.ms = 10000
        sasl.login.retry.backoff.ms = 100
        sasl.mechanism = GSSAPI
        sasl.oauthbearer.clock.skew.seconds = 30
        sasl.oauthbearer.expected.audience = null
        sasl.oauthbearer.expected.issuer = null
        sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
        sasl.oauthbearer.jwks.endpoint.url = null
        sasl.oauthbearer.scope.claim.name = scope
        sasl.oauthbearer.sub.claim.name = sub
        sasl.oauthbearer.token.endpoint.url = null
        security.protocol = PLAINTEXT
        security.providers = null
        send.buffer.bytes = 131072
        socket.connection.setup.timeout.max.ms = 30000
        socket.connection.setup.timeout.ms = 10000
        ssl.cipher.suites = null
        ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
        ssl.endpoint.identification.algorithm = https
        ssl.engine.factory.class = null
        ssl.key.password = null
        ssl.keymanager.algorithm = SunX509
        ssl.keystore.certificate.chain = null
        ssl.keystore.key = null
        ssl.keystore.location = null
        ssl.keystore.password = null
        ssl.keystore.type = JKS
        ssl.protocol = TLSv1.3
        ssl.provider = null
        ssl.secure.random.implementation = null
        ssl.trustmanager.algorithm = PKIX
        ssl.truststore.certificates = null
        ssl.truststore.location = null
        ssl.truststore.password = null
        ssl.truststore.type = JKS

2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka version: 3.5.0
2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka commitId: c97b88d5db4de28d
2025-02-03 22:51:10,339 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka startTimeMs: 1738623070338
2025-02-03 22:51:10,353 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,354 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,458 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,458 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,560 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,560 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:10,864 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:10,864 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:11,272 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:11,272 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:12,190 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:12,190 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:13,316 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:13,317 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:14,234 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:14,235 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:15,151 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Node -1 disconnected.
2025-02-03 22:51:15,152 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Connection to node -1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-03 22:51:15,346 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.i.AdminMetadataManager: [AdminClient clientId=kui-admin-client-validation-1738623070231] Metadata update failed
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: fetchMetadata
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.u.AppInfoParser: App info kafka.admin.client for kui-admin-client-validation-1738623070231 unregistered
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.i.AdminMetadataManager: [AdminClient clientId=kui-admin-client-validation-1738623070231] Metadata update failed
org.apache.kafka.common.errors.TimeoutException: The AdminClient thread has exited. Call: fetchMetadata
2025-02-03 22:51:15,372 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.a.KafkaAdminClient: [AdminClient clientId=kui-admin-client-validation-1738623070231] Timed out 1 remaining operation(s) during close.
2025-02-03 22:51:15,379 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Metrics scheduler closed
2025-02-03 22:51:15,380 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Closing reporter org.apache.kafka.common.metrics.JmxReporter
2025-02-03 22:51:15,380 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738623070231] o.a.k.c.m.Metrics: Metrics reporters closed
2025-02-03 22:51:15,380 ERROR [parallel-3] c.p.k.u.u.KafkaServicesValidation: Error connecting to cluster
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: listTopics
2025-02-03 22:51:15,385 INFO  [parallel-3] audit: {"timestamp":"2025-02-03T22:51:15.384400375Z","username":"Unknown","resources":[],"operation":"validateConfig","result":{"success":true}}

I have a local Kafka cluster running at localhost:9092. This is using the default Kafka docker image from here: https://hub.docker.com/layers/apache/kafka/latest/images/sha256-515a27c1fef65dab7ea736d27369d866e2bcb0ab7e28273541e7280842fe0128

Using the standard kafka bin scripts, I can do:

bin/kafka-topics.sh --list --bootstrap-server localhost:9092

And get back:

test-topic1
test-topic2

Screenshots

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Logs

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Additional context

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[github-actions]

Hi beachwood23! 👋

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[Haarolean]

1. versions <1.x.x are no longer supported
2. the issue lies within the misunderstanding of how docker networks work, localhost for the k-ui container is equal to a host within the container, not your bare-metal 'localhost'. See this old long thread: How to connect to local (bare-metal, outside a container) kafka instance provectus/kafka-ui#1081
   TL;DR: you have to use a specific hostname to connect to a bare-metal host, like host.docker.internal which may depend on your host OS.

[beachwood23]

@Haarolean Thank you for reviewing.

1. I am running the latest image available on docker. How is this not supported? I have run docker pull provectuslabs/kafka-ui and the image is up to date.

2. Thank you for helping me recall this. I have tried with host.docker.internal as well, and unfortunately see the same error. I am still not sure if connecting to a local cluster is supported. It is interesting, because the bootstrap.servers recognize that we are trying to use host.docker.internal, and yet the Kafka-UI service is trying to connect to Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.

I see this output:

2025-02-04 15:08:38,086 INFO  [main] c.p.k.u.KafkaUiApplication: Started KafkaUiApplication in 2.493 seconds (process running for 2.888)
2025-02-04 15:10:11,375 INFO  [reactor-http-nio-4] o.a.k.c.a.AdminClientConfig: AdminClientConfig values:
        auto.include.jmx.reporter = true
        bootstrap.servers = [host.docker.internal:9092]
        client.dns.lookup = use_all_dns_ips
        client.id = kui-admin-client-validation-1738681811369
        connections.max.idle.ms = 300000
        default.api.timeout.ms = 5000
        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 = 5000
        retries = 1
        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.connect.timeout.ms = null
        sasl.login.read.timeout.ms = 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.login.retry.backoff.max.ms = 10000
        sasl.login.retry.backoff.ms = 100
        sasl.mechanism = GSSAPI
        sasl.oauthbearer.clock.skew.seconds = 30
        sasl.oauthbearer.expected.audience = null
        sasl.oauthbearer.expected.issuer = null
        sasl.oauthbearer.jwks.endpoint.refresh.ms = 3600000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms = 10000
        sasl.oauthbearer.jwks.endpoint.retry.backoff.ms = 100
        sasl.oauthbearer.jwks.endpoint.url = null
        sasl.oauthbearer.scope.claim.name = scope
        sasl.oauthbearer.sub.claim.name = sub
        sasl.oauthbearer.token.endpoint.url = null
        security.protocol = PLAINTEXT
        security.providers = null
        send.buffer.bytes = 131072
        socket.connection.setup.timeout.max.ms = 30000
        socket.connection.setup.timeout.ms = 10000
        ssl.cipher.suites = null
        ssl.enabled.protocols = [TLSv1.2, TLSv1.3]
        ssl.endpoint.identification.algorithm = https
        ssl.engine.factory.class = null
        ssl.key.password = null
        ssl.keymanager.algorithm = SunX509
        ssl.keystore.certificate.chain = null
        ssl.keystore.key = null
        ssl.keystore.location = null
        ssl.keystore.password = null
        ssl.keystore.type = JKS
        ssl.protocol = TLSv1.3
        ssl.provider = null
        ssl.secure.random.implementation = null
        ssl.trustmanager.algorithm = PKIX
        ssl.truststore.certificates = null
        ssl.truststore.location = null
        ssl.truststore.password = null
        ssl.truststore.type = JKS

2025-02-04 15:10:11,440 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka version: 3.5.0
2025-02-04 15:10:11,440 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka commitId: c97b88d5db4de28d
2025-02-04 15:10:11,440 INFO  [reactor-http-nio-4] o.a.k.c.u.AppInfoParser: Kafka startTimeMs: 1738681811439
2025-02-04 15:10:11,629 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:11,630 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:11,731 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:11,731 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:11,936 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:11,936 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:12,140 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:12,140 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:12,646 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:12,646 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:13,364 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:13,365 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:14,383 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:14,384 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:15,499 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Node 1 disconnected.
2025-02-04 15:10:15,500 WARN  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.NetworkClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Connection to node 1 (localhost/127.0.0.1:9092) could not be established. Broker may not be available.
2025-02-04 15:10:16,448 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.u.AppInfoParser: App info kafka.admin.client for kui-admin-client-validation-1738681811369 unregistered
2025-02-04 15:10:16,448 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.a.i.AdminMetadataManager: [AdminClient clientId=kui-admin-client-validation-1738681811369] Metadata update failed
org.apache.kafka.common.errors.TimeoutException: The AdminClient thread has exited. Call: fetchMetadata
2025-02-04 15:10:16,453 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.a.KafkaAdminClient: [AdminClient clientId=kui-admin-client-validation-1738681811369] Timed out 1 remaining operation(s) during close.
2025-02-04 15:10:16,457 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.m.Metrics: Metrics scheduler closed
2025-02-04 15:10:16,458 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.m.Metrics: Closing reporter org.apache.kafka.common.metrics.JmxReporter
2025-02-04 15:10:16,458 INFO  [kafka-admin-client-thread | kui-admin-client-validation-1738681811369] o.a.k.c.m.Metrics: Metrics reporters closed
2025-02-04 15:10:16,458 ERROR [parallel-2] c.p.k.u.u.KafkaServicesValidation: Error connecting to cluster
org.apache.kafka.common.errors.TimeoutException: Timed out waiting for a node assignment. Call: listTopics
2025-02-04 15:10:16,475 INFO  [parallel-2] audit: {"timestamp":"2025-02-04T15:10:16.464937794Z","username":"Unknown","resources":[],"operation":"validateConfig","result":{"success":true}}

[vaibhav-tech15]

Hey @beachwood23 , by any chance did you find a way out for this issue? I’m facing exactly the same error and am running out of ideas now.

[Haarolean]

@vaibhav-tech15 provectus/kafka-ui#1081

[hrjAtLC]

Easiest solution is to use --net="host" in your docker run command, then localhost in your docker container will point to your docker host. I confirmed this is working on Linux. Not sure of other environments.