image buildのworkflowを1ファイルにまとめる

.github/workflows/staging.yaml → .github/workflows/image.yaml

@@ -1,39 +1,55 @@
-name: Build image (main)
+name: Build image
 
 on:
+  workflow_dispatch:
   push:
     branches:
       - main
+    tags:
+      - v*
+  pull_request:
+    branches:
+      - main
 
 env:
   IMAGE_NAME: traportfolio
-  IMAGE_TAG: main
 
 jobs:
-  image:
+  build:
+    name: Build Docker Image
     permissions:
       contents: read
       packages: write
     runs-on: ubuntu-latest
     steps:
+      - uses: actions/checkout@v4
+      - name: Generate Image Tags
+        uses: docker/metadata-action@v5
+        id: meta
+        with:
+          images: ghcr.io/traptitech/${{ env.IMAGE_NAME }}
       - name: Login to GitHub Container Registry
+        if: github.event_name != 'pull_request'
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
           username: traptitech
           password: ${{ secrets.GITHUB_TOKEN }}
-      - uses: actions/checkout@v4
       - name: Build and push
         uses: docker/build-push-action@v6
         with:
           context: .
-          push: true
+          push: ${{ github.event_name != 'pull_request' }}
           platforms: linux/amd64
-          tags: ghcr.io/traptitech/${{ env.IMAGE_NAME }}:${{ env.IMAGE_TAG }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+
   deploy-staging:
-    name: Deploy staging
+    name: Deploy to staging
+    if: github.event_name == 'push' && github.ref_name == 'main'
     runs-on: ubuntu-latest
-    needs: [image]
+    needs:
+      - build
     steps:
       - name: Install SSH key
         uses: shimataro/ssh-key-action@v2