Скачать или смотреть Resolving the Issue of Testcontainers Starting Two Containers in Spring Boot Projects

Learn how to fix the issue of Testcontainers starting two containers instead of one in your Spring Boot tests by adjusting your Flyway and datasource properties.
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Troubleshooting Testcontainers in Spring Boot Projects

Introduction

If you're using Testcontainers with Spring Boot and have encountered a situation where two containers are being started instead of one during your tests, you're not alone! This is a common issue that can arise due to a misconfiguration in your application properties, particularly with Flyway and datasource setup. Not only does this lead to unnecessary overhead, but it can also result in failed tests due to the second container not containing the expected data.

In this guide, we will guide you through understanding the problem and show you how to effectively resolve it to ensure that only one container is launched during your tests.

Understanding the Problem

In a typical Spring Boot application using Testcontainers, you may experience unexpected behavior such as:

The first container starts and executes Flyway scripts successfully.

Shortly after, a second container is initiated without running Flyway scripts.

As a result, tests fail because the second container lacks the necessary data.

To illustrate the issue, let’s consider the following example. In your test setup, you've defined properties that control the connection to your PostgreSQL database through Testcontainers. Here's what your property file looks like:

[[See Video to Reveal this Text or Code Snippet]]

Based on your logs, it's evident that two containers are created when running tests:

[[See Video to Reveal this Text or Code Snippet]]

This duplication is typically caused by having conflicting datasource properties.

Solution

Step 1: Revise Your Property Configuration

To resolve the issue of multiple containers being created, you will need to adjust your properties by removing duplicate user and password entries that are associated with Flyway. Here’s how you can do this effectively:

Before Changes

Your original configuration looks something like this:

[[See Video to Reveal this Text or Code Snippet]]

After Changes

To eliminate the conflict, simplify your properties as follows:

[[See Video to Reveal this Text or Code Snippet]]

Step 2: Verify and Test

Once you have updated your property file:

Run your tests again to verify that only one Testcontainer instance is starting.

Check the logs to ensure there is no mention of a second container being created.

Conclusion

By simply removing the duplicated user and password properties for Flyway, you can prevent Spring Boot from starting two containers unnecessarily. This not only streamlines your testing process but also enhances the reliability of your tests.

Feel free to implement these changes and observe the improvements in your testing framework using Testcontainers. Thank you for reading, and happy coding!