Flutter and Automatic Versioning

Yes, it’s definitely possible.

Step 1: Add Version Plugin

Add the version plugin to your pubspec.yaml file under the dev_dependencies section:

dev_dependencies:
version: ^2.0.0

The version plugin provides a way to manage the version number of your application and generate version-related code.

Step 2: Configure Version Plugin

Create a new file named version.dart in the lib/ directory of your project, and add the following code to it:

import 'package:version/version.dart';

final version = Version(0, 1, 0);

This creates a version variable with an initial version number of 0.1.0. This version number will be automatically incremented based on the commits following the Conventional Commits structure.

Step 3: Configure GitLab Pipeline

Create a .gitlab-ci.yml file in the root directory of your project and add the following code to it:

stages:
  - build
  - release

flutter_build:
  stage: build
  image: cirrusci/flutter:stable
  script:
    - flutter packages get
    - flutter build apk
  artifacts:
    paths:
      - build/app/outputs/flutter-apk/app-release.apk

release:
  stage: release
  image: cirrusci/flutter:stable
  script:
    - flutter packages get
    - flutter pub get
    - version patch
    - git add pubspec.yaml lib/version.dart
    - git commit -m "Bump version to ${CI_COMMIT_TAG}"
    - git tag -a "${CI_COMMIT_TAG}" -m "Version ${CI_COMMIT_TAG}"
    - git push origin "${CI_COMMIT_TAG}"

This pipeline consists of two stages: build and release. In the build stage, we build the Flutter APK and save it as an artifact. In the release stage, we increment the version number using the version patch command, commit the changes to the pubspec.yaml and lib/version.dart files, and tag the commit with the new version number. Finally, we push the tag to the remote Git repository.

Step 4: Configure GitLab Environment Variables

In order to use the version plugin, we need to set up two environment variables in the GitLab pipeline:

• FLUTTER_ROOT: the path to the Flutter SDK
• PUB_CACHE: the path to the pub cache directory

Add the following environment variables to your GitLab project:

• FLUTTER_ROOT: /opt/flutter
• PUB_CACHE: $CI_PROJECT_DIR/.pub-cache

Step 5: Create a New Release

To create a new release, follow these steps:

Push a commit following the Conventional Commits structure. For example:

feat: add new feature

Create a new tag with the v prefix and the new version number. For example:

git tag -a v0.1.1 -m "Version 0.1.1"

Push the tag to the remote Git repository:

git push origin v0.1.1

The GitLab pipeline will automatically trigger the release stage and increment the version number in the version.dart file, commit the changes, and tag the commit with the new version number.

The new release APK will be available as an artifact in the GitLab pipeline, under the build/app/outputs/flutter-apk/ directory.