Run an Elixir Phoenix Container App
Back4App Containers is a powerful platform for hosting Elixir Phoenix applications. With its ability to automatically deploy Dockerized apps, you can launch your project in a scalable and flexible environment with ease. In this guide, we will walk you through the process of preparing and deploying your Elixir Phoenix application on Back4App Containers, covering everything from simple projects to more complex setups. We will begin with the necessary preparations, then move on to dockerizing the application, testing it locally, pushing the project to GitHub, setting up the project on Back4App Containers, monitoring deployment, and troubleshooting common issues.
If you have any questions or comments, feel free to join the conversation in the #Containers channel on the Back4app Community on Slack. Anytime you can also contact us at [email protected].
To prepare your Elixir Phoenix application for deployment on Back4app Containers, you'll need to complete the following steps:
- Ensure your application is built using the latest Elixir and Phoenix versions. You can update your Elixir and Phoenix versions by updating your mix.exs file with the latest dependency versions.
- Remove any hard-coded configurations, such as database URLs or secret keys. Instead, use environment variables to store these values, which you can then set within Back4App Containers. This ensures that your application is more secure and easy to configure when deploying to different environments.
- Make sure your application is using the correct environment settings, such as production, development, or test environments. Update your config/*.exs files to use environment variables for these settings.
- Compile your application using the MIX_ENV=prod mix compile command. This will generate the necessary build artifacts for deployment.
- Create a .dockerignore file in the root directory of your application to exclude unnecessary files and directories from the Docker build context. This will help reduce the size of your Docker image and improve build times.
- Ensure your application is running correctly locally by testing it with MIX_ENV=prod mix phx.server. If everything is working correctly, you're ready to move on to the next step: Dockerization.
To create a Dockerfile for your Elixir Phoenix application, follow these steps:
- Create a new file named Dockerfile in the root directory of your application.
- Add the following content to your Dockerfile:
This Dockerfile sets up a basic Elixir Phoenix application using the official Elixir image. It installs the required dependencies and compiles the application, then exposes port 4000 and starts the application using mix phx.server.
Before pushing your project to GitHub and deploying it to Back4App Containers, you should test your Dockerized application locally . To do this, follow these steps:
- Build your Docker image with the following command:
- Run your Docker container with the following command:
- Access your application in your web browser at http://localhost:4000. If everything is working correctly, you're ready to move on to the next step: Pushing your project to GitHub.
To push your Elixir Phoenix application to a GitHub repository, follow these steps:
- If you haven't already, create a new GitHub repository for your project.
- Initialize a Git repository in your project's root directory using the command git init.
- Add all your project files to the Git repository using the command git add ..
- Commit your changes with a meaningful message using the command git commit -m "Your commit message".
- Add the remote GitHub repository to your local Git repository using the command git remote add origin https://github.com/your-username/your-repository.git.
- Push your changes to the remote GitHub repository using the command git push -u origin master.
With your project now on GitHub, you can proceed to deploy your application on Back4App Containers.
To deploy your Rails app on Back4app Containers, start by logging in to your Back4app account and connecting your GitHub repository to the platform. Once connected, navigate to the Containers section and create a new container app. During this process, you can customize your Dockerfile path, and also create any necessary environment variables required by your application. You can follow these Docs for a better guidance:
In summary, containers will follow the instructions detailed on your Dockerfile and start to create your App.
After configuring your container app, Back4app will automatically build the container image using your Dockerfile and deploy your Rails app on the platform. The deployment process may take a few minutes, depending on the size and complexity of your application.
Once the deployment is complete, Back4app Containers will provide you with a unique URL where you can access your deployed app.
While your application is being deployed on Back4App Containers, you can monitor the progress and check for any errors or warnings. To do this, follow these steps:
- In your Back4App Containers dashboard, click on your application's name to view its details.
- Click on the "Logs" tab to view real-time logs of the deployment process.
- Pay close attention to any error or warning messages that may appear, as they could indicate potential issues with your application or its configuration.
- If necessary, make any required changes to your application or its configuration and redeploy your application.
Here is a list of common problems you might encounter when deploying and running an Elixir Phoenix application on Back4App Containers, along with some suggested solutions:
- Docker build fails: If your Docker build fails, carefully review the error messages in the logs. Common issues include missing dependencies, incorrect file paths, or syntax errors in your Dockerfile. Make sure to address these issues and try rebuilding your application.
- Application fails to start: If your application fails to start after deployment, examine the logs for any error messages. These could indicate issues with your application's configuration, such as missing environment variables or incorrect settings. Make sure your application is correctly configured and redeploy it if necessary.
- Application runs but is not accessible: If your application is running but not accessible via the assigned URL, double-check your application's config/*.exs files to ensure that the correct port and host settings are being used. Additionally, ensure that your Dockerfile exposes the correct port by including the EXPOSE directive.
- Application performance issues: If your application experiences performance issues or runs slowly, consider optimizing your application's code or configuration. This may involve tweaking database settings, reducing the number of concurrent connections, or implementing caching. Additionally, you can consider scaling your application on Back4App Containers by increasing the number of containers or upgrading to a more powerful container plan.
- Application crashes or experiences intermittent issues: If your application crashes or experiences intermittent issues, examine the logs to identify any patterns or error messages that may indicate the root cause. Common issues include memory leaks, unhandled exceptions, or improperly closed connections. Once you've identified the issue, update your application's code or configuration as necessary and redeploy it.
If your Phoenix application requires more resources to perform optimally, you can easily scale your Back4app Containers vertically by purchasing a more powerful container with higher CPU and memory allocations. This will allow your application to handle increased traffic and provide a better user experience.
For a reference implementation, you can access a template Phoenix app deployed on Back4app Containers at the following link: https://github.com/templates-back4app/containers-elixir-phoenix
By following this guide, you should now have a better understanding of how to deploy and manage your Elixir Phoenix applications on Back4App Containers. With its powerful features and easy-to-use interface, Back4App Containers is an excellent platform for hosting your applications while leaving the complexities of DevOps to the experts.