[Feature]: Add a method to GenericContainer to expose a random container port with the same number as the host port

[linghengqian]

Module

Core

Problem

• Currently, it is not possible to expose a random port in a container to the same random port on the host. To achieve this goal, you can only use the deprecated class org.testcontainers.containers.FixedHostPortGenericContainer. For HiveServer2 with Zookeeper service discovery enabled, there are similar operations as follows.

import org.apache.curator.test.InstanceSpec;
import org.junit.jupiter.api.Test;
import org.testcontainers.containers.FixedHostPortGenericContainer;
import org.testcontainers.containers.GenericContainer;
import org.testcontainers.containers.Network;
public class ExampleTest {
    @Test
    void test() {
        Network network = Network.newNetwork();
        int randomPort = InstanceSpec.getRandomPort();
        try (
                GenericContainer<?> zookeeper = new GenericContainer<>("zookeeper:3.9.3-jre-17")
                        .withNetwork(network)
                        .withNetworkAliases("foo")
                        .withExposedPorts(2181);
                GenericContainer<?> hiveServer2 = new FixedHostPortGenericContainer<>("apache/hive:4.0.1")
                        .withNetwork(network)
                        .withEnv("SERVICE_NAME", "hiveserver2")
                        .withFixedExposedPort(randomPort, randomPort)
                        .dependsOn(zookeeper)
        ) {
            zookeeper.start();
            hiveServer2.withEnv("SERVICE_OPTS", "-Dhive.server2.support.dynamic.service.discovery=true" + " "
                    + "-Dhive.zookeeper.quorum=" + zookeeper.getNetworkAliases().get(0) + ":2181" + " "
                    + "-Dhive.server2.thrift.bind.host=0.0.0.0" + " "
                    + "-Dhive.server2.thrift.port=" + randomPort);
            hiveServer2.start();
        }
    }
}

• The only purpose of org.apache.curator.test.InstanceSpec#getRandomPort() is to get a random host port. This can sometimes conflict with the port in the container.
• This is like a Docker Compose unit like this,

services:
  zookeeper:
    image: zookeeper:3.9.3-jre-17
    ports:
      - "12181:2181"
  apache-hive-1:
    image: apache/hive:4.0.1
    depends_on:
      - zookeeper
    environment:
      SERVICE_NAME: hiveserver2
      SERVICE_OPTS: >-
        -Dhive.server2.support.dynamic.service.discovery=true
        -Dhive.zookeeper.quorum=zookeeper:2181
        -Dhive.server2.thrift.bind.host=0.0.0.0
        -Dhive.server2.thrift.port=23593
    ports:
      - "23593:23593"

• There is almost no way around org.testcontainers.containers.FixedHostPortGenericContainer to use a random numeric port both on the host, inside the container, and in the container's environment variables.

Solution

• I was expecting there to be a method in GenericContainer to expose the same host port number on a random container port. If this method is called org.testcontainers.containers.GenericContainer#withRandomExposedPorts(), it can expose a random container port. And allow the host to obtain this port number through org.testcontainers.containers.GenericContainer#getFirstMappedPort(), then the use of org.testcontainers.containers.FixedHostPortGenericContainer can obviously be simplified to,

import org.junit.jupiter.api.Test;
import org.testcontainers.containers.GenericContainer;
import org.testcontainers.containers.Network;
public class ExampleTest {
    @Test
    void test() {
        Network network = Network.newNetwork();
        try (
                GenericContainer<?> zookeeper = new GenericContainer<>("zookeeper:3.9.3-jre-17")
                        .withNetwork(network)
                        .withNetworkAliases("foo")
                        .withExposedPorts(2181);
                GenericContainer<?> hiveServer2 = new GenericContainer<>("apache/hive:4.0.1")
                        .withNetwork(network)
                        .withEnv("SERVICE_NAME", "hiveserver2")
                        .withRandomExposedPorts()
                        .dependsOn(zookeeper)
        ) {
            zookeeper.start();
            hiveServer2.withEnv("SERVICE_OPTS", "-Dhive.server2.support.dynamic.service.discovery=true" + " "
                    + "-Dhive.zookeeper.quorum=" + zookeeper.getNetworkAliases().get(0) + ":2181" + " "
                    + "-Dhive.server2.thrift.bind.host=0.0.0.0" + " "
                    + "-Dhive.server2.thrift.port=" + hiveServer2.getFirstMappedPort());
            hiveServer2.start();
        }
    }
}

Benefit

• This helps simplify the process of starting a HiveServer2 with Zookeeper service discovery enabled.

Alternatives

• Using org.testcontainers.containers.FixedHostPortGenericContainer can indeed directly solve the current issue, which is what Support connecting to HiveServer2 with ZooKeeper Service Discovery enabled in GraalVM Native Image apache/shardingsphere#33768 and Improve GraalVM Reachability Metadata and corresponding nativeTest related unit tests apache/shardingsphere#29052 are doing.
• But the problem is that org.testcontainers.containers.FixedHostPortGenericContainer has been deprecated.

Would you like to help contributing this feature?

No