Docker : Re-use container image by caching

Question

Here I have two workflows under a job. The only target we want to achieve is that, we want to reuse the container images by using cache or some other means. Similar way we do for node_modules

jobs:
    build:
        name: build
        runs-on: [self-hosted, x64, linux, research]
        container:
          image: <sample docker image>
        env:
          NPM_AUTH_TOKEN: <sample token>
        steps:
          - uses: actions/checkout@v2
          - name: Install
            run: |
              npm install
          - name: Build
            run: |
          npm build
    Test:
        name: Test Lint
        runs-on: [self-hosted, x64, linux, research]
        container:
          image: <sample docker image>
        env:
          NPM_AUTH_TOKEN: <sample token>
        steps:
          - uses: actions/checkout@v2
          - name: Install Dependencies
            run: npm ci
          - name: Lint Check
            run: npm run lint

Answer 1

I would suggest using the Docker's Build Push action for this purpose. Through the build-push-action, you can cache your container images by using the inline cache, registry cache or the experimental cache backend API:

Inline cache

name: Build and push
uses: docker/build-push-action@v2
with:
    context: .
    push: true
    tags: user/app:latest
    cache-from: type=registry,ref=user/app:latest
    cache-to: type=inline

Refer to the Buildkit docs.

Registry Cache

name: Build and push
uses: docker/build-push-action@v2
with:
    context: .
    push: true
    tags: user/app:latest
    cache-from: type=registry,ref=user/app:buildcache
    cache-to: type=registry,ref=user/app:buildcache,mode=max

Refer to Buildkit docs.

Cache backend API

name: Build and push
uses: docker/build-push-action@v2
with:
    context: .
    push: true
    tags: user/app:latest
    cache-from: type=gha
    cache-to: type=gha,mode=max

Refer to Buildkit docs.

I personally prefer using the Cache backend API as its easy to setup and provides a great boost in reducing the overall CI pipeline run duration.

---

By looking at the comments, it seems you want to share Docker cache between workflows. In this case you can share Docker containers between jobs in a workflow using this example:

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      -
        name: Checkout
        uses: actions/checkout@v2
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v1
      -
        name: Build and push
        uses: docker/build-push-action@v2
        with:
          context: .
          file: ./Dockerfile
          tags: myimage:latest
          outputs: type=docker,dest=/tmp/myimage.tar
      -
        name: Upload artifact
        uses: actions/upload-artifact@v2
        with:
          name: myimage
          path: /tmp/myimage.tar

  use:
    runs-on: ubuntu-latest
    needs: build
    steps:
      -
        name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v1
      -
        name: Download artifact
        uses: actions/download-artifact@v2
        with:
          name: myimage
          path: /tmp
      -
        name: Load Docker image
        run: |
          docker load --input /tmp/myimage.tar
          docker image ls -a