Java gradle kafka-avro-serializer 和 kafka-schema-registry-client 在部署管道中下载失败

Question

Trying to deploy our service in the cloud I am facing the issue that two transitive dependencies could not been downloaded with the error:

Welcome to Gradle 6.7.1!
Here are the highlights of this release:
 - File system watching is ready for production use
 - Declare the version of Java your build requires
 - Java 15 support
For more details see https://docs.gradle.org/6.7.1/release-notes.html
Starting a Gradle Daemon (subsequent builds will be faster)
> Task :compileJava FAILED
FAILURE: Build failed with an exception.
* What went wrong:
Execution failed for task ':compileJava'.
> Could not resolve all files for configuration ':compileClasspath'.
   > Could not resolve io.confluent:kafka-avro-serializer:5.3.2.
     Required by:
         project :
         project : > org.apache.beam:beam-runners-google-cloud-dataflow-java:2.32.0 > org.apache.beam:beam-sdks-java-io-kafka:2.32.0
      > Could not resolve io.confluent:kafka-avro-serializer:5.3.2.
         > Could not get resource 'http://packages.confluent.io/maven/io/confluent/kafka-avro-serializer/5.3.2/kafka-avro-serializer-5.3.2.pom'.
            > Could not GET 'http://packages.confluent.io/maven/io/confluent/kafka-avro-serializer/5.3.2/kafka-avro-serializer-5.3.2.pom'.
               > Connection reset
   > Could not resolve io.confluent:kafka-schema-registry-client:5.3.2.
     Required by:
         project :
         project : > org.apache.beam:beam-runners-google-cloud-dataflow-java:2.32.0 > org.apache.beam:beam-sdks-java-io-kafka:2.32.0
      > Could not resolve io.confluent:kafka-schema-registry-client:5.3.2.
         > Could not get resource 'http://packages.confluent.io/maven/io/confluent/kafka-schema-registry-client/5.3.2/kafka-schema-registry-client-5.3.2.pom'.
            > Could not GET 'http://packages.confluent.io/maven/io/confluent/kafka-schema-registry-client/5.3.2/kafka-schema-registry-client-5.3.2.pom'.
               > Connection reset

Most resolutions that I could find in the web and here on stackoverflow are centered around adding a new confluent.io gradle repository:

repositories {
    mavenCentral()
    maven {
        url "http://packages.confluent.io/maven/"
    }
}

I tried both http and https. Neither changed anything in the cloud.

I tried to add the transitive dependencies direct to the project gradle. This approach was not succesful too:

    implementation group: 'io.confluent', name: 'kafka-avro-serializer', version: '5.3.2'
    implementation group: 'io.confluent', name: 'kafka-schema-registry-client', version: '5.3.2'

What could be the Issue? How to best approach this Problem?

Answer 1

The firewall in the cloud was blocking the requests. For some reason they were classified not as http , but as confluent requests, which the firewall did not knew about and therefore were blocking. The aimed at a "confluent" app within the k8s. I don't know where this app comes from, but... Enabling those requests solved the issue.