Update docker workflow (#50)

.github/workflows/docker.yaml

@@ -5,7 +5,7 @@ on:
     branches: 
       - master
     tags:
-      - '*'
+      - 'v*'
 
 jobs:
   main:
@@ -15,11 +15,15 @@ jobs:
         uses: actions/checkout@v2
 
       - name: Docker meta
-        id: docker_meta
+        id: meta
         uses: crazy-max/ghaction-docker-meta@v2.1.1
         with:
           images: distribyted/distribyted
-          tag-sha: true
+          tags: |
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
 
       - name: Set up QEMU
         uses: docker/setup-qemu-action@v1
@@ -37,9 +41,10 @@ jobs:
         id: docker_build
         uses: docker/build-push-action@v2
         with:
-          push: true
-          tags: ${{ steps.docker_meta.outputs.tags }}
-          labels: ${{ steps.docker_meta.outputs.labels }}
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}
           platforms: linux/386,linux/amd64,linux/arm/v6,linux/arm/v7,linux/arm64
       
       - name: Update repo description