Add ghcr.io images build and push

Author: Felixoid

.github/workflows/docker.yml

@@ -0,0 +1,47 @@
+name: Docker images
+
+on:
+  push:
+    branches: [ master ]
+    tags: [ 'v*' ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  docker:
+    name: Build image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out code
+        uses: actions/checkout@v2
+      - name: Docker meta
+        id: meta
+        uses: docker/metadata-action@v3
+        with:
+          images: ghcr.io/${{ github.repository }}
+          # create latest tag for branch events
+          flavor: |
+            latest=${{ github.event_name == 'push' && github.ref_type == 'branch' }}
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}.{{minor}}.{{patch}}
+      - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v1
+        with:
+          registry: ghcr.io
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+      - name: Build and push
+        id: docker_build
+        uses: docker/build-push-action@v2
+        with:
+          # push for non-pr events
+          push: ${{ github.event_name != 'pull_request' }}
+          context: .
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
+