Cache dockerhub images from linux for macOS (nektos#768)

* Cache dockerhub images from linux for macOS

An attempt to avoid hitting the dockerhub Pull Rate Limit.

* parallelize / refactor docker cache

Co-authored-by: Casey Lee <cplee@nektos.com>

.github/workflows/checks.yml

@@ -2,6 +2,10 @@ name: checks
 on: [pull_request, workflow_dispatch]
 
 env:
+  ACT_OWNER: ${{ github.repository_owner }}
+  ACT_REPOSITORY: ${{ github.repository }}
+  CACHED_DOCKER_IMAGES: '"node:12-buster" "node:12-buster-slim" "ubuntu:18.04" "ubuntu:latest" "alpine:3.10" "tonistiigi/binfmt:latest"'
+  CACHED_DOCKER_IMAGES_KEY: docker-images-0
   GO_VERSION: 1.17
 
 jobs:
@@ -61,14 +65,49 @@ jobs:
           files: coverage.txt
           fail_ci_if_error: true # optional (default = false)
 
+  dump_images:
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    steps:
+      - uses: actions/cache@v2
+        id: image_cache
+        with:
+          key: ${{ env.CACHED_DOCKER_IMAGES_KEY }}
+          path: |
+            registry
+            docker-registry
+      - name: Pull and export images
+        if: steps.image_cache.outputs.cache-hit != 'true'
+        run: |
+          docker pull registry:2
+          docker image save -o registry registry:2
+          mkdir -p docker-registry
+          docker run -d -p 5000:5000 --name registry -v $PWD/docker-registry:/var/lib/registry registry:2
+          npx wait-on tcp:5000
+          for image in ${{ env.CACHED_DOCKER_IMAGES }}
+          do
+            bash -c 'docker pull "'"$image"'" && docker tag "'"$image"'" "localhost:5000/'"$image"'" && docker push "localhost:5000/'"$image"'"'&
+          done
+          wait
+
   test-macos:
+    needs: dump_images
     name: test-macos
     runs-on: macos-latest
     continue-on-error: true # Don't let macos test fail whole workflow
     env:
       ISO_PATH: ~/.docker/machine/cache/boot2docker.iso
     steps:
       - uses: actions/checkout@v2
+      - name: Restore Docker Image Cache
+        uses: actions/cache@v2
+        id: image_cache
+        continue-on-error: true
+        with:
+          key: ${{ env.CACHED_DOCKER_IMAGES_KEY }}
+          path: |
+            registry
+            docker-registry
       - uses: actions/setup-go@v1
         with:
           go-version: ${{ env.GO_VERSION }}
@@ -100,9 +139,23 @@ jobs:
           echo "DOCKER_HOST=$DOCKER_HOST" | tee -a $GITHUB_ENV
           echo "DOCKER_CERT_PATH=$DOCKER_CERT_PATH" | tee -a $GITHUB_ENV
           echo "DOCKER_MACHINE_NAME=$DOCKER_MACHINE_NAME" | tee -a $GITHUB_ENV
-          printf " 🛠️ Install Qemu for running containers with different architecture 🛠️ \n\n"
-          docker run --rm --privileged tonistiigi/binfmt --install all
           printf " 🛠️ Finished installing Docker 🛠️ \n\n"
+      - name: Import images
+        if: steps.image_cache.outputs.cache-hit == 'true'
+        continue-on-error: true
+        run: |
+          echo load registry
+          docker image load -i registry
+          echo Setup local registry
+          docker run -d -p 5000:5000 --name registry -v $PWD/docker-registry:/var/lib/registry registry:2
+          echo pulling images from cache
+          for image in ${{ env.CACHED_DOCKER_IMAGES }}
+          do
+            bash -c '(sleep 1 && docker pull "localhost:5000/'"$image"'" || sleep 2 && docker pull "localhost:5000/'"$image"'" || sleep 10 && docker pull "localhost:5000/'"$image"'") && docker tag "localhost:5000/'"$image"'" "'"$image"'"'&
+          done
+          wait
+      - name: 🛠️ Install Qemu for running containers with different architecture 🛠️
+        run: docker run --rm --privileged tonistiigi/binfmt:latest --install all
       - run: go test -v -timeout 30m -cover ./...
         env:
           CGO_ENABLED: 0