Resolve "Split tag and publish CI/CD steps"

Closes #27 (closed)

.gitlab-ci.yml

 image: ghcr.io/cirruslabs/flutter:latest
 
 stages:
-  - build-debug
-  - release
+  - publish-check
+  - release-tag
+  - release-publish
 
-android:build-debug:
-  stage: build-debug
+# Check flutter package
+package:publish-check:
+  stage: publish-check
   except:
     - tags
     - master
   script:
-    # Check flutter package
     - VERSION_NAME="$(grep '^version:' pubspec.yaml | cut -d' ' -f2)"
     - echo "${VERSION_NAME}"
     - TAG_NAME="${VERSION_NAME}"
@@ -24,15 +25,20 @@ android:build-debug:
     - flutter pub publish --dry-run
   interruptible: true
 
-application:release:
-  stage: release
+# Create git tag on new release
+package:release-tag:
+  stage: release-tag
+  image:
+    name: alpine/git
+    entrypoint: [""]
   only:
     - master
   except:
     - tags
   dependencies:
-    - android:build-debug
+    - package:publish-check
   script:
+    - apk --no-cache add curl
     - git config user.email "${GITLAB_USER_EMAIL}"
     - git config user.name "${GITLAB_USER_NAME}"
     - git remote set-url origin https://oauth2:${GITLAB_ACCESS_TOKEN}@${CI_SERVER_HOST}/${CI_PROJECT_PATH}
@@ -46,9 +52,24 @@ application:release:
       else
         git tag -a "${TAG_NAME}" -m "Release ${VERSION_NAME}"
         git push origin "${TAG_NAME}"
-        flutter clean
-        flutter packages get
-        echo "${PRIVATE_PACKAGES_REPOSITORY_KEY}" | flutter pub token add https://pub.harrault.fr
-        flutter pub publish --force
         curl --silent -d "{\"token\": \"${JABBER_NOTIFICATION_TOKEN}\", \"message\": \"New tag for ${CI_PROJECT_PATH}: ${TAG_NAME}\"}" -H "Content-Type: application/json" -X POST ${JABBER_NOTIFICATION_URL}
       fi
+
+# Publish package to private repository
+package:release-publish:
+  stage: release-publish
+  only:
+    - master
+  except:
+    - tags
+  dependencies:
+    - package:release-tag
+  script:
+    - echo "${PRIVATE_PACKAGES_REPOSITORY_KEY}" | flutter pub token add https://pub.harrault.fr
+    - VERSION_NAME="$(grep '^version:' pubspec.yaml | cut -d' ' -f2)"
+    - echo "${VERSION_NAME}"
+    - flutter clean
+    - flutter packages get
+    - flutter pub publish --force
+    - >
+      curl --silent -d "{\"token\": \"${JABBER_NOTIFICATION_TOKEN}\", \"message\": \"New package published for ${CI_PROJECT_PATH}: ${VERSION_NAME}\"}" -H "Content-Type: application/json" -X POST ${JABBER_NOTIFICATION_URL}