Share built image between jobs with GitHub Actions

As each job is isolated in its own runner, you can't use your built image between jobs, except if you're using self-hosted runners However, you can pass data between jobs in a workflow using the actions/upload-artifact and actions/download-artifact actions:

name: ci

on:
  push:
    branches:
      - "main"

jobs:
  build:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout
        uses: actions/checkout@v4
      - name: Set up Docker Buildx
        uses: docker/setup-buildx-action@v3
      - name: Build and export
        uses: docker/build-push-action@v5
        with:
          context: .
          tags: myimage:latest
          outputs: type=docker,dest=/tmp/myimage.tar
      - name: Upload artifact
        uses: actions/upload-artifact@v3
        with:
          name: myimage
          path: /tmp/myimage.tar

  use:
    runs-on: ubuntu-latest
    needs: build
    steps:
      - name: Download artifact
        uses: actions/download-artifact@v3
        with:
          name: myimage
          path: /tmp
      - name: Load image
        run: |
          docker load --input /tmp/myimage.tar
          docker image ls -a