Docker Container Issues: A Guide for On-Premise Deployments

Introduction

Docker containers have revolutionized the way applications are managed and deployed. However, like any technology, they can encounter issues that might disrupt your experience. This article aims to guide you through the process of checking whether your Docker containers are running when facing access issues to your application. Specifically designed for on-premise deployments, this guide will help you identify and resolve common container-related problems.

Identifying Access Issues

When attempting to access your application's web page, you might encounter error messages such as "This site can't be reached" or "example.iriusrisk.com refused to connect." These errors can occur for various reasons, and it's important to eliminate basic possibilities before diving deeper into the troubleshooting process.

Basic Checks

Before delving into Docker container issues, consider the following basic checks:

1. Internet Connection: Ensure that your internet connection is stable by trying to access other websites.
2. Correct URL: Verify that you've entered the correct URL to access your application.
3. Alternative Device/Network: Attempt to access the application from a different device or network to rule out local issues.
4. Clear Cache/Cookies: Clear your browser's cache and cookies, as sometimes they can lead to unexpected errors.

Troubleshooting Docker Containers

If you've ruled out the basics and are still experiencing issues, it's time to investigate your Docker containers. A common reason for access problems is that the Docker containers might not be running properly.

Using docker ps

The docker ps command is a valuable tool in checking the status of your Docker containers. This command allows you to list all the currently running containers on your system. When you execute docker ps, it provides you with an overview of the active containers, including details like container ID, names, status, ports, and more.

Identifying Non-Running Containers

In the event that one or more of your containers are not running, they will not appear in the list generated by the docker ps command. This indicates that there might be an issue with the container's startup or execution. Non-running containers can cause accessibility problems, leading to the error messages you encountered earlier.

Solution: Restarting Containers

 If you identify non-running containers using the docker ps command, it's time to bring them back up. A simple way to restart all containers specified in your deployment is by using the docker-compose up -d command. This command will initiate the startup of all containers mentioned in your Docker Compose configuration file, ensuring that they are running and accessible.

Verifying Container Recovery After Restart

Once you've restarted your containers using the docker-compose up -d command, you can run docker ps again to see the list of currently running containers. Previously non-running containers should now be listed with a status of "Up" along with their uptime in the status column.

Conclusion

By ruling out basic factors and leveraging Docker's tools like docker ps, you can swiftly identify whether your containers are running as they should be.