Feature: Docker multiarch image (amd64 & arm64) dynamic tags and ghcr repositoy (#400)

* Enabled multiarch build with buildx, qemu and also enabled ghcr, improved tagging

- Enabled multiarch build with buildx, qemu and also enabled ghcr
- Improved image tagging
- Getting rid unknown/unknonw architecture in ghcr
    - https://github.com/docker/build-push-action
    - https://docs.docker.com/build/attestations/slsa-provenance/
    - https://github.com/docker/build-push-action/issues/820

* Switched to lukechannings/deno docke rimage as proposed in #136

- silverbulletmd/silverbullet/issues/136

(cherry picked from commit 176b70f5481dbbef9744818662f47617903de209)

* Added tini, condensed Dockerfile Run to one step, cleaning up image

- tini is missing in new base image, so I added it manually, as
  documented in https://github.com/krallin/tini

(cherry picked from commit 4d549b8f5b45bcc9ea04a0e7a4fdc3c82cdd7f5c)

* Using TARGETARCH for downloading tini

(cherry picked from commit 23a6019da00115b34c3bd09eb0c733172edcebbc)

.github/workflows/docker.yml

@@ -2,9 +2,17 @@ name: Docker
 
 on:
   push:
+    branches:
+      - "main"
     tags:
-      - '*'
-
+      - "**"
+env:
+  DENO_VERSION: v1.32.5
+  # Docker & Registries
+  ARCHITECTURES: linux/amd64,linux/arm64
+  IMAGE_NAME: silverbullet
+  NAMESPACE_GITHUB: silverbulletmd
+  NAMESPACE_DOCKER: zefhemel
 jobs:
   docker-build-push:
     runs-on: ubuntu-latest
@@ -13,10 +21,20 @@ jobs:
       - name: Setup repo
         uses: actions/checkout@v3
 
+      - name: Set up QEMU for multi-arch builds with buildx
+        uses: docker/setup-qemu-action@v2
+        with:
+          platforms: ${{ env.ARCHITECTURES }}
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+        with:
+          platforms: ${{ env.ARCHITECTURES }}
+
       - name: Setup Deno
         uses: denoland/setup-deno@d4873ceeec10de6275fecd1f94b6985369d40231
         with:
-          deno-version: v1.32.5
+          deno-version: ${{ env.DENO_VERSION }}
 
       - name: Run bundle build
         run: |
@@ -29,11 +47,42 @@ jobs:
           username: ${{ secrets.DOCKERHUB_USERNAME }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
-      - name: Build and push
-        uses: docker/build-push-action@v3
+      - name: Log in to the ghcr Container registry
+        uses: docker/login-action@v2
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      #
+      # MetaData Extract Docu: <https://github.com/docker/metadata-action>
+      #
+      - name: Extract metadata (tags, labels) for Docker
+        id: meta
+        uses: docker/metadata-action@v4.4.0
+        with:
+          images: |
+            # Set the different image names(paces) for docker-hub & ghcr
+            ${{ env.NAMESPACE_DOCKER }}/${{ env.IMAGE_NAME }}
+            ghcr.io/${{ env.NAMESPACE_GITHUB }}/${{ env.IMAGE_NAME }}
+          tags: |
+            # <https://github.com/docker/metadata-action#typeref>
+            # minimal (short sha), enable f desired
+            # type=sha,enable=true,priority=100,prefix=commit-,suffix=,format=short
+            # set latest tag for default branch
+            type=raw,value=latest,enable={{is_default_branch}}
+            # 
+            # tag w/ full tag part of git tag: <https://github.com/docker/metadata-action#typesemver>
+            # only present for `on.push.tags` !
+            type=semver,pattern={{raw}},enable=true
+            # type=edge,branch=develop # usually this would be the develop branch
+
+      - name: Build and push Docker images
+        uses: docker/build-push-action@v4.0.0
         with:
           context: .
+          platforms: ${{ env.ARCHITECTURES }}
           push: true
-          tags: |
-            zefhemel/silverbullet:latest
-            zefhemel/silverbullet:${{ github.ref_name }}
+          # Disable to get rid of unknown architecture in ghcr
+          provenance: false
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}