Скачать или смотреть Solving the Issue of Docker Multi-Stage Build Not Running All Stages

A detailed guide on why your Docker multi-stage build might stop prematurely and how upgrading Spring Boot can resolve the issue.
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Troubleshooting Docker Multi-Stage Builds in Spring Boot

Docker's multi-stage build feature is a game changer for many developers, allowing for efficient image size and layered architecture. However, issues can arise that leave you scratching your head. One common problem is when a multi-stage build appears to execute only the first stage, skipping the subsequent ones. If you're experiencing this issue while developing a Spring Boot application, don't worry. This guide will shed light on the problem and provide you with a solution.

Understanding the Issue: Why is My Multi-Stage Build Stopping?

You may have a Dockerfile that looks something like this:

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

When building this Docker image, you might notice that the process stops after executing the line:

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

Even though the build steps counter shows that the first stage completed, the second stage never executes, which can be quite perplexing.

The Root Cause: Compatibility with Spring Boot Version

Upon investigation, it turns out that the culprit behind this issue is related to the version of Spring Boot you are using. Specifically, prior versions do not fully support Docker's multi-stage build capabilities. This limitation can lead to unintended behavior where the build process cannot transition from one stage to the next.

What Changed with Spring Boot 2.3.x?

With the release of Spring Boot 2.3.x, significant improvements were made to ensure compatibility with Docker multi-stage builds. Key enhancements include:

Better Layer Management: Improved handling of the classpath to extract the necessary layers.

Extended Command Options: More control over how Spring Boot manages the application lifecycle within Docker containers.

The Solution: Upgrade to Spring Boot 2.3.x

The simplest solution to this multi-stage build issue is to upgrade your Spring Boot version. Here’s how you can do that:

Update Your Dependency:

Locate your pom.xml file (for Maven projects) or build.gradle file (for Gradle projects).

Change the Spring Boot version to at least 2.3.0:

For Maven:

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

For Gradle:

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

Rebuild Your Docker Image:

Run the Docker build command again, and now both stages should complete successfully.

Test Your Application:

After the build completes, run your container and verify that everything is working as expected.

Conclusion

Docker multi-stage builds can greatly enhance your workflow, but compatibility issues can still cause headaches. In this case, the problem was rooted in the Spring Boot version being used. By upgrading to at least version 2.3.x, you can unlock the full potential of Docker’s multi-stage builds and streamline your application deployment process.

Final Thoughts

Keep your dependencies up to date and regularly review documentation to ensure compatibility with your tools. Don’t let Docker and Spring Boot integration issues slow you down—empower yourself with the knowledge to tackle these challenges head-on!