build: use mint to minify container images

.github/actions/setup-mint/action.yml

@@ -0,0 +1,19 @@
+name: mint
+description: Setup https://github.com/mintoolkit/mint
+
+runs:
+  using: composite
+  steps:
+    - name: Setup mint
+      run: |
+        mkdir -p "$HOME/.local/bin"
+        cd "$HOME/.local/bin"
+
+        # Get the current released tag_name
+        VER=$(curl -sL https://api.github.com/repos/mintoolkit/mint/releases \
+          | grep tag_name | head -n1 | cut -d'"' -f4)
+        curl -L -o mint.tar.gz "https://github.com/mintoolkit/mint/releases/download/${VER}/dist_linux.tar.gz"
+        tar -xvf mint.tar.gz --strip-components 1
+
+        echo "Installed mint:${VER}"
+      shell: bash

.github/workflows/continuous-integration.yml

@@ -59,11 +59,15 @@ jobs:
         with:
           name: showcase
           path: dist/
-      - name: 'Container: Login to GitHub Container Repository'
-        run: echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io --username ${{ github.actor }} --password-stdin
-      - name: 'Container: Build image'
-        run: docker build -t $IMAGE_REPO:latest .
+      - uses: ./.github/actions/setup-mint
+      - name: 'Container: Build and push image'
+        run: |
+          echo ${{ secrets.GITHUB_TOKEN }} | docker login ghcr.io --username ${{ github.actor }} --password-stdin
+          docker build -t $IMAGE_REPO:latest-fat .
+          mint slim \
+            --target $IMAGE_REPO:latest-fat \
+            --tag $IMAGE_REPO:latest \
+            --preserve-path /usr/share/nginx/html
+          docker push $IMAGE_REPO:latest
         env:
           DOCKER_BUILDKIT: 1
-      - name: 'Container: Publish image'
-        run: docker push $IMAGE_REPO:latest