get your flutter app to build itself - automated android builds

1.
Intro
2.
Steps
2.1.
Create the workflow file
2.2.
Configure the workflow
2.2.1.
Workflows Events
2.2.2.
Define the Workflow Job
2.2.3.
Checkout the repository
2.2.4.
Setup Flutter
2.2.5.
Install Dependencies
2.2.6.
Build the APK
2.2.7.
Upload apk to the artifacts

Intro

Lets automate the build of a flutter android app using Github Actions. By using github actions, you can save your time and resources from builds done locally.

Steps

First create a new repository on github and upload your flutter project to your github account.

If you prefer to understand the worflow, follow along. If you dont know how to do that, just press the + button on top right of github homepage, create the repository and the upload your files.

If you are a copy/paste person, fire away to this github gist link.

Create the workflow file

Now, create a folder .github/workflows in root of your project.

Create a file named build.yml in that folder. Github action will automatically pick up the configurations we will setup in a while.

Configure the workflow

Lets define the name of the github actions workflow. (be mindful of the tabs and spaces, those matter in a .yml or yaml file)

name: Flutter Android Build

Workflows Events

Now, lets set the events that will trigger the workflow. workflow_dispatch gives you a button to trigger the workflow on your will with a button.

on:
  push:
    branches:
      - main
  workflow_dispatch: # trigger on a button click

Define the Workflow Job

In GitHub Actions, jobs are used to define the tasks that need to be executed. For our workflow, we are naming the job flutter-android-build. This job will run on the latest version of Ubuntu provided by GitHub Actions.

jobs:
  flutter-android-build:
    runs-on: ubuntu-latest

Checkout the repository

The first step in our job is to checkout the repository. This allows GitHub Actions to access the code in your repository.

    steps:
        - name: Checkout Repository
        uses: actions/checkout@v2

Setup Flutter

Next, we need to set up the Flutter environment. We use the subosito/flutter-action action to specify the Flutter version that we want to use, which in this case is 3.10.6.

    - name: Setup Flutter
        uses: subosito/flutter-action@v2
        with:
            flutter-version: "3.10.6"

Install Dependencies

Before building the APK, we need to install the necessary dependencies. This is done using the flutter pub get command, which fetches all the dependencies listed in your project's pubspec.yaml file.

    - name: Install Dependencies
        run: flutter pub get

Build the APK

With the dependencies installed, we can now build the APK. We use the flutter build apk --release command to build a release version of the APK, which is optimized for distribution.

    - name: Build APK
        run: flutter build apk --release

Upload apk to the artifacts

Finally, we archive the built APK using the actions/upload-artifact action. This makes the APK available as an artifact in the GitHub Actions workflow run, allowing you to download it from the GitHub interface.

  - name: Archive Artifacts
    uses: actions/upload-artifact@v2
    with:
      name: app-release
      path: build/app/outputs/flutter-apk/app-release.apk

Now you can ensure an always ready-to-distribute APK without the need for manual builds!

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