Errors in examples/messaging at the stage of building (Kafka) and running (JMS) applications

[mic216]

Environment Details

• Helidon Version: 2.2.0, 2.2.1
• Helidon SE or Helidon MP: SE
• JDK version: 11
• OS: Linux
• Docker version (if applicable): 19.03.13

---

Problem Description

Hi, I found two bugs in examples/messaging https://github.com/oracle/helidon/tree/2.2.0/examples/messaging at the stage of building. The problems are easily reproducible.
The first one is that kafkaRun.sh script seems to be obsolete. Stack traces:

[+] Building 6.8s (7/12)
=> [internal] load build definition from Dockerfile.kafka 1.1s
=> => transferring dockerfile: 44B 0.0s
=> [internal] load .dockerignore 1.7s
=> => transferring context: 2B 0.0s
=> [internal] load metadata for docker.io/library/openjdk:8-jre-alpine 2.4s
=> [1/8] FROM docker.io/library/openjdk:8-jre-alpine@sha256:f362b165b870ef129cbe730f29065ff37399c0aa8bcab3e44b51c302938c9193 0.0s
=> [internal] load build context 0.8s
=> => transferring context: 70B 0.0s
=> CACHED [2/8] RUN apk add --no-cache bash curl jq gcompat 0.0s
=> ERROR [3/8] RUN MIRROR=$(curl -s 'https://www.apache.org/dyn/closer.cgi?as_json=1' | jq -r '.http[0]') && wget -q -O kafka.tar.gz ${MIRROR}kafka/2.5.0/kafka_2.12-2.5.0.tgz && tar -xzf kafka.tar.gz -C /opt && rm ka 2.5s
[3/8] RUN MIRROR=$(curl -s 'https://www.apache.org/dyn/closer.cgi?as_json=1' | jq -r '.http[0]') && wget -q -O kafka.tar.gz ${MIRROR}kafka/2.5.0/kafka_2.12-2.5.0.tgz && tar -xzf kafka.tar.gz -C /opt && rm kafka.tar.gz && mv /opt/kafka* /opt/kafka:
#6 2.236 wget: server returned error: HTTP/1.1 404 Not Found
failed to solve with frontend dockerfile.v0: failed to build LLB: executor failed running [/bin/sh -c MIRROR=$(curl -s 'https://www.apache.org/dyn/closer.cgi?as_json=1' | jq -r '.http[0]') && wget -q -O kafka.tar.gz ${MIRROR}kafka/${VERSION}/kafka_2.12-${VERSION}.tgz && tar -xzf kafka.tar.gz -C /opt && rm kafka.tar.gz && mv /opt/kafka* /opt/kafka]: runc did not terminate sucessfully
Unable to find image 'helidon-test-kafka:latest' locally
docker: Error response from daemon: pull access denied for helidon-test-kafka, repository does not exist or may require 'docker login': denied: requested access to the resource is denied.
See 'docker run --help'.

And the second one is related to JMS. I can run JMS docker container using "docker run --name='activemq' --rm -p 61616:61616 -p 8161:8161 rmohr/activemq" but it doesn't seem to be available in the web browser. Moreover, running jms-websocket-se application fails and its stack traces are:

log4j:WARN No appenders could be found for logger (org.apache.activemq.util.ThreadPoolUtils).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.
Exception in thread "main" io.helidon.messaging.MessagingException: Error when creating JMS producer.
at io.helidon.messaging.connectors.jms.JmsConnector.getSubscriberBuilder(JmsConnector.java:356)
at io.helidon.messaging.MessagingImpl.findConnectors(MessagingImpl.java:161)
at java.base/java.util.HashMap$Values.forEach(HashMap.java:976)
at io.helidon.messaging.MessagingImpl.start(MessagingImpl.java:63)
at io.helidon.examples.messaging.se.SendingService.(SendingService.java:71)
at io.helidon.examples.messaging.se.Main.startServer(Main.java:67)
at io.helidon.examples.messaging.se.Main.main(Main.java:51)
Caused by: javax.jms.JMSException: Could not connect to broker URL: tcp://127.0.0.1:61616. Reason: java.net.ConnectException: Connection refused (Connection refused)
at org.apache.activemq.util.JMSExceptionSupport.create(JMSExceptionSupport.java:36)
at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:374)
at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:304)
at org.apache.activemq.ActiveMQConnectionFactory.createConnection(ActiveMQConnectionFactory.java:244)
at io.helidon.messaging.connectors.jms.JmsConnector.prepareSession(JmsConnector.java:453)
at io.helidon.messaging.connectors.jms.JmsConnector.getSubscriberBuilder(JmsConnector.java:345)
... 6 more
Caused by: java.net.ConnectException: Connection refused (Connection refused)
at java.base/java.net.PlainSocketImpl.socketConnect(Native Method)
at java.base/java.net.AbstractPlainSocketImpl.doConnect(AbstractPlainSocketImpl.java:399)
at java.base/java.net.AbstractPlainSocketImpl.connectToAddress(AbstractPlainSocketImpl.java:242)
at java.base/java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:224)
at java.base/java.net.SocksSocketImpl.connect(SocksSocketImpl.java:403)
at java.base/java.net.Socket.connect(Socket.java:609)
at org.apache.activemq.transport.tcp.TcpTransport.connect(TcpTransport.java:525)
at org.apache.activemq.transport.tcp.TcpTransport.doStart(TcpTransport.java:488)
at org.apache.activemq.util.ServiceSupport.start(ServiceSupport.java:55)
at org.apache.activemq.transport.AbstractInactivityMonitor.start(AbstractInactivityMonitor.java:169)
at org.apache.activemq.transport.InactivityMonitor.start(InactivityMonitor.java:52)
at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64)
at org.apache.activemq.transport.WireFormatNegotiator.start(WireFormatNegotiator.java:72)
at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64)
at org.apache.activemq.transport.TransportFilter.start(TransportFilter.java:64)
at org.apache.activemq.ActiveMQConnectionFactory.createActiveMQConnection(ActiveMQConnectionFactory.java:354)
... 10 more

Steps to reproduce

Kafka issue:

cd helidon/examples/messaging
./kafkaRun.sh

JMS issue:

docker run --name='activemq' --rm -p 61616:61616 -p 8161:8161 rmohr/activemq
cd helidon/examples/messaging/jms-websocket-se
mvn clean install
java -jar target/helidon-examples-jms-websocket-se.jar

[mic216]

I fixed Kafka issue, it is enough to upgrade to 2.7.0 version from 2.5.0 version in examples/messaging/docker/kafka/Dockerfile.kafka. ENV VERSION=2.5.0 -> ENV VERSION=2.7.0

[danielkec]

Hi nice catch! Apache mirrors no longer publish version 2.5.0, new dockerfile version #2768 resolves latest version for installation.

[danielkec]

Are you sure rmohr/activemq image started correctly for you? Just tested freshly pulled image and works as expected:

[mic216]

@danielkec Ok, rmohr/activemq now works. I don't know why it didn't work earlier.

Btw, I wanted to create communication between two microservices using kafka server and I want to ask: what is the best practice to make kafka server working merely in backend, because I found that /examples/messaging/kafka-websocket-se works only if javascript WebSocket is opened at frontend. How to make websocket working in clean helidon (backend) without necessity of opening js ws at frontend?

[danielkec]

Not sure if I do understand the question, but if you want to try SE messaging with Kafka without frontend attached take a look at this little example https://github.com/danielkec/streaming-sasl (ignore the graal substitution) it's simple one file example of sending and receiving in console

[danielkec]

You can also find detailed step by step explanation in this article https://medium.com/helidon/helidon-2-0-with-kafka-b97ba4f422bd