build: update docker beta build to latest actions and to push to ghcr

* Add ghcr option for docker images
* Update to use the upstream build actions
* Add ability to push beta images manually.

.github/workflows/build_publish_docker_image.yml

@@ -4,6 +4,7 @@ on:
     push:
       branches:
         - master
+    workflow_dispatch:
 
 jobs:
     build:
@@ -15,12 +16,47 @@ jobs:
               uses: actions/checkout@v3
               with:
                 fetch-depth: 0
-            - name: Build and publish image
-              uses: ilteoood/docker_buildx@1.1.0
+            - name: Login to Docker Hub
+              uses: docker/login-action@v2
               with:
-                tag: beta
-                imageName: rclone/rclone
-                platform: linux/amd64,linux/386,linux/arm64,linux/arm/v7,linux/arm/v6
-                publish: true
-                dockerHubUser: ${{ secrets.DOCKER_HUB_USER }}
-                dockerHubPassword: ${{ secrets.DOCKER_HUB_PASSWORD }}
+                username: ${{ secrets.DOCKERHUB_USERNAME }}
+                password: ${{ secrets.DOCKERHUB_TOKEN }}
+            - name: Extract metadata (tags, labels) for Docker
+              id: meta
+              uses: docker/metadata-action@v4
+              with:
+                images: ghcr.io/${{ github.repository }}
+            - name: Set up QEMU
+              uses: docker/setup-qemu-action@v2
+            - name: Set up Docker Buildx
+              uses: docker/setup-buildx-action@v2
+            - name: Login to GitHub Container Registry
+              uses: docker/login-action@v2
+              with:
+                registry: ghcr.io
+                # This is the user that triggered the Workflow. In this case, it will
+                # either be the user whom created the Release or manually triggered
+                # the workflow_dispatch.
+                username: ${{ github.actor }}
+                # `secrets.GITHUB_TOKEN` is a secret that's automatically generated by
+                # GitHub Actions at the start of a workflow run to identify the job.
+                # This is used to authenticate against GitHub Container Registry.
+                # See https://docs.github.com/en/actions/security-guides/automatic-token-authentication#about-the-github_token-secret
+                # for more detailed information.
+                password: ${{ secrets.GITHUB_TOKEN }}
+
+            - name: Build and publish image
+              uses: docker/build-push-action@v3
+              with:
+                file: Dockerfile-alpine
+                context: .
+                push: true # push the image to ghcr
+                tags: |
+                  ghcr.io/rclone/rclone:beta
+                  rclone/rclone:beta
+                labels: ${{ steps.meta.outputs.labels }}
+                platforms: linux/amd64,linux/386,linux/arm64,linux/arm64,linux/arm/v7,linux/arm/v6
+                cache-from: type=gha
+                cache-to: type=gha,mode=max
+              # Eventually cache will need to be cleared if builds more frequent than once a week
+              # https://github.com/docker/build-push-action/issues/252