How to Dockerize and Automate Flutter App Deployment

This is the fifth article in our “How To” DevOps series, where we break down practical deployment strategies for modern application development. 

In previous articles, we covered Dockerization for Android, Python with Django, .NET MVC, and PHP. In this guide, we focus on Flutter and explain how to Dockerize, automate builds, and streamline deployment workflows using Docker and development containers. 

If you are building scalable Flutter applications and want consistent environments across teams, Docker can significantly simplify your development lifecycle. 

 

Why Dockerize a Flutter Application? 

Docker allows developers to package applications along with their dependencies into isolated containers. This ensures consistent builds across development, staging, and production environments. 

For Flutter development, containerization helps: 

• Maintain consistent SDK versions 

• Avoid system dependency conflicts 

• Simplify CI and CD automation 

• Improve team collaboration 

• Enable environment portability 

Flutter is widely used for cross-platform mobile app development, making environment consistency even more important when working across macOS, Windows, and Linux systems. 

 

Prerequisites 

Before starting, ensure you have: 

• Docker installed 

• Visual Studio Code installed 

• Remote Development extension in VS Code 

• Basic knowledge of Dockerfile structure 

Verify Docker installation by running: 

docker –version 

You should see a valid Docker version installed on your system. 

 

Step 1: Create Project Directory 

1. Create a new folder, for example:
   flutter_project_docker 

1. Open the folder in Visual Studio Code using: 

code flutter_project_docker 

 

Step 2: Create a Dockerfile 

Inside your project folder, create a file named: 

Dockerfile 

A Dockerfile is a text file containing instructions to build a Docker image. It defines: 

• Base image 

• Required dependencies 

• Flutter SDK installation 

• User permissions 

• Environment configuration 

This file ensures your Flutter app builds inside a standardized container environment. 

 

Step 3: Configure Dev Container 

To enable a fully containerized development workflow: 

1. Create a folder named: 

.devcontainer 

1. Inside it, create: 

devcontainer.json 

1. Link the Dockerfile inside the configuration. 

Important note for macOS and Windows users:
Avoid incorrectly defining folder paths inside devcontainer.json, as this may cause container build failures. 

 

Step 4: Create Workspace Folder 

Create a separate workspace folder where your Flutter projects will reside. This directory will be mounted inside the container and used for: 

• Creating Flutter projects 

• Writing application code 

• Managing dependencies 

This keeps your container clean and organized. 

 

Step 5: Build and Run the Docker Container 

1. Open VS Code. 

1. Click the Remote Development icon on the left panel. 

1. Select:
   Remote Containers: Open Folder in Container 

1. Choose the root directory and build the container. 

Docker will now build your Flutter development environment. 

 

Step 6: Verify Flutter Installation 

Once inside the container, run: 

flutter doctor 

This verifies the setup. 

You may notice: 

• Warning related to Android Studio 

• No connected device detected 

These warnings are normal if Android Studio plugins are not installed or no device is connected. 

 

Step 7: Connect Android Device 

To run your Flutter app: 

1. Connect your Android device via USB 

1. Set connection mode to PTP 

1. Run: 

flutter devices 

1. Then run your project using: 

flutter run 

Or create a new project: 

flutter create project_name 

Now you can develop and deploy your Flutter app entirely inside a Docker container. 

 

Automating Build and Deployment 

Once Dockerization is complete, you can integrate the setup with CI CD tools such as: 

• GitHub Actions 

• GitLab CI 

• Jenkins 

This enables automated: 

• Image builds 

• Test execution 

• Deployment pipelines 

Docker ensures that your build environment remains consistent across all stages. 

 

Benefits of Dockerizing Flutter Projects 

• Eliminates “works on my machine” issues 

• Simplifies onboarding for new developers 

• Enables reproducible builds 

• Supports scalable DevOps practices 

• Reduces environment configuration time 

 

What’s Next? 

Dockerization is just the beginning. In our upcoming article, we will explore how Docker and Kubernetes can help reduce infrastructure costs and improve scalability in production environments. 

At 9series, we specialize in DevOps automation, containerization, and scalable mobile app development solutions. If you are planning to streamline your Flutter development workflow with Docker, our experts can help you implement a production-ready architecture. 

Stay tuned for the next article in our DevOps series.