ci: 👷 add steps to create slimmed images for latest and tagged versio…

…ns (#186)

.github/workflows/build.yml

@@ -62,17 +62,18 @@ jobs:
             type=ref,event=pr
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
-            type=sha
+            type=sha,format=long
             type=raw,value=latest,enable={{is_default_branch}}
 
-      # Build and push Docker image with Buildx (don't push on PR)
+      # Build and push Docker image with Buildx
       # https://github.com/docker/build-push-action
       - name: Build and push Docker image
         id: build-and-push
         uses: docker/build-push-action@94d76d3bc1409736cb5dc1ada9502bec3a72973c
         with:
           context: .
           push: ${{ github.event_name != 'pull_request' }}
+          load: true
           tags: ${{ steps.meta.outputs.tags }}
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=gha
@@ -91,3 +92,26 @@ jobs:
         # against the sigstore community Fulcio instance.
         run: echo "${{ steps.meta.outputs.tags }}" | xargs -I {} cosign sign {}@${{
           steps.build-and-push.outputs.digest }}
+
+      # Slim the container builds with Slim toolkit
+      - name: Slim the latest container build version
+        uses: kitabisa/docker-slim-action@v1
+        env:
+          DSLIM_HTTP_PROBE: false
+        with:
+          target: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:sha-${{ github.sha }}
+          tag: latest-slim
+
+      - name: Slim the semver container build version
+        if: ${{ github.event_name != 'pull_request' }}
+        uses: kitabisa/docker-slim-action@v1
+        env:
+          DSLIM_HTTP_PROBE: false
+        with:
+          target: ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ github.ref_name }}
+          tag: ${{ github.ref_name }}-slim
+
+      # Push the slimmed container builds to the registry except on PRs.
+      - name: Push the slimmed container builds to the registry
+        if: ${{ github.event_name != 'pull_request' }}
+        run: docker push ${{ env.REGISTRY }}/${{ env.IMAGE_NAME }} --all-tags