RedisTestContainer.java

package com.example.solidconnection.support;

import org.springframework.boot.test.util.TestPropertyValues;
import org.springframework.context.ApplicationContextInitializer;
import org.springframework.context.ConfigurableApplicationContext;
import org.testcontainers.containers.GenericContainer;

public class RedisTestContainer implements ApplicationContextInitializer<ConfigurableApplicationContext> {

    private static final int ORIGINAL_PORT = 6379;
    private static final GenericContainer<?> CONTAINER = new GenericContainer<>("redis:7.0")
            .withExposedPorts(ORIGINAL_PORT);

    static {
        CONTAINER.start();
    }

    @Override
    public void initialize(ConfigurableApplicationContext applicationContext) {
        TestPropertyValues.of(
                "spring.data.redis.host=" + CONTAINER.getHost(),
                "spring.data.redis.port=" + CONTAINER.getMappedPort(ORIGINAL_PORT)
        ).applyTo(applicationContext.getEnvironment());
    }
}