Run a Deno Container App
Back4App Containers is a powerful platform for hosting Deno applications. With its ability to automatically deploy Dockerized Deno 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 Deno 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.
To prepare your Deno application for deployment on Back4App Containers, follow these steps:
- Make sure you have the latest version of Deno installed on your local machine. You can check the version by running deno --version and upgrade if necessary.
- Structure your project with a clear directory hierarchy, placing source files in a src directory, and configuration files in a config directory.
- Add a deps.ts file to your project to manage your dependencies. This file should import and export all the external libraries your application uses.
- Use environment variables to manage configuration settings, such as database URLs, API keys, and port numbers. This will make it easier to configure your application when deploying it to Back4App Containers.
- Ensure that your application has proper error handling and logs useful information for debugging purposes.
- Add a README.md file to your project, which includes instructions for running your application, along with any prerequisites or configuration settings required.
Create a Dockerfile in the root directory of your project to define your Docker image. A sample Dockerfile for a Deno application could look like this:
To test your project locally, run the following command in your terminal:
Open your browser and navigate to http://localhost:8080 to ensure your application is running correctly.
To push your project to a new GitHub repository, follow these steps:
- Create a new repository on GitHub, and copy its URL.
- In your local project directory, run the following commands:
To deploy your Deno 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.
To monitor the deployment of your Deno application on Back4App Containers, follow these steps:
- In the Back4App Containers dashboard, navigate to your container's details page.
- Check the deployment logs for any error messages or warnings that may occur during the deployment process.
- If you encounter any errors, make the necessary changes to your project and push the changes to your GitHub repository. Back4App Containers will automatically redeploy your application with the updated code.
Here is a list of common problems you might encounter when deploying and running a Deno application on Back4App Containers, along with their solutions:
- Missing dependencies: Make sure you have included all required dependencies in your deps.ts file and that they are imported and exported correctly. Verify that the deps.ts file is properly cached in your Dockerfile.
- Incorrect environment variables: Ensure that you have correctly configured the environment variables for your application in the Back4App Containers dashboard. Double-check the variable names and values to ensure they match what your Deno application expects.
- Port conflicts: If your application does not start or is not accessible, it could be due to a port conflict. Verify that the port number specified in your Deno application matches the port number configured in the Back4App Containers dashboard. Also, ensure that the --allow-net flag is set correctly in your Dockerfile.
- Application crashes: If your application crashes or exits unexpectedly, check the logs for error messages or stack traces. Make sure your Deno application has proper error handling in place and logs useful information for debugging purposes.
- Docker build failures: If your Docker build fails, double-check your Dockerfile for syntax errors or missing instructions. Ensure that you are using the correct base image and that all required files are copied into the Docker image during the build process.
By addressing these common issues, you can successfully deploy and run your Deno application on Back4App Containers, taking advantage of the platform's powerful features for scaling and managing your application with ease.