Скачать или смотреть Resolving Connection Refused Issues in Dockerized Laravel Applications with MariaDB

Learn how to troubleshoot and fix the `connection refused` error in Docker when deploying Laravel applications with MariaDB. Follow this guide for a clear explanation of configuration changes to resolve the issue.
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This video is based on the question https://stackoverflow.com/q/77047277/ asked by the user 'Jonathan Rendón' ( https://stackoverflow.com/u/22505963/ ) and on the answer https://stackoverflow.com/a/77047420/ provided by the user 'Peter van der Wal' ( https://stackoverflow.com/u/2903251/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

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Introduction

Deploying a web application can sometimes feel like a puzzle, especially when working with technologies like Docker, Laravel, and MariaDB. One common issue that developers encounter is the Connection refused error when trying to connect to the database. In this article, we'll break down the problem and provide a step-by-step solution to ensure your application can communicate seamlessly with your MariaDB instance.

The Problem

In the setup you have described, you're using a Docker environment to orchestrate your application services. This includes a Laravel app, a MariaDB database, and phpMyAdmin for database management. Despite being able to ping different containers and not seeing any errors in the logs, your application is unable to connect to the database.

This leads us to investigate the configuration files for your Docker setup:

.env File for environment variables

docker-compose.yml to define service configurations

Dockerfile for building your application image

Here's a snapshot of the relevant settings from your environment file:

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

And from your docker-compose.yml:

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

Key Observations

The database is exposed on port 3306 within the container, which is typical for MariaDB/MySQL.

Your .env file specifies port 3307 for DB_PORT, but this does not align with the internal port where MariaDB is listening (3306).

The Solution

To resolve the connection refused error, we need to align the environment variables with the appropriate MariaDB ports. Here's how you can achieve that:

1. Adjusting the Environment Variables

In your .env file, change the DB_PORT to reflect the internal port used by MariaDB:

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

In this configuration:

DB_PORT now points to 3306, the port that MariaDB listens to internally.

EXPOSE_DB_PORT indicates that we still want to expose our MariaDB service on port 3307 outside the container.

2. Updating the Docker Compose File

Next, update your docker-compose.yml to reflect the change we made to the .env file:

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

This line ensures that the database is still accessible externally via port 3307, while the application can connect internally at port 3306.

3. Keeping the database.php Configuration

You can keep your current database.php configuration as it is, as it already references the environment variables correctly:

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

Conclusion

By aligning your configuration properly and ensuring that the internal and external ports match the expected values, you can resolve the Connection refused error when using Docker with Laravel and MariaDB.

Next time you encounter connection issues, remember to check both the exposed ports and the internal listening ports within your containers. This straightforward adjustment could save you hours of debugging!

Summary

Issue: Connection refused error due to port misconfiguration.

Solution:

Update .env to set DB_PORT to 3306.

Modify docker-compose.yml to expose the database port as 3307 while listening on 3306.

Outcome: Improved connection stability between Laravel and MariaDB in Docker.

With these steps, your application should now be able to connect to the database without any issues. Happy coding!