added github action for docker image

.github/workflows/docker.yml

@@ -0,0 +1,56 @@
+name: Build and push images
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - "*"
+      - "!README.md"
+    tags:
+      - 'v*.*.*'
+  pull_request:
+    branches:
+      - 'master'
+
+jobs:
+  docker:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Docker meta
+        id: meta
+        uses: crazy-max/ghaction-docker-meta@v2
+        with:
+          # list of Docker images to use as base name for tags
+          images: |
+            prayagsingh/prometheus-jibri-exporter
+          # generate Docker tags based on the following events/attributes
+          tags: |
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=pr
+            type=semver,pattern={{version}}
+            type=semver,pattern={{major}}.{{minor}}
+            type=semver,pattern={{major}}
+            type=sha
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v1
+
+      - name: Login to DockerHub
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v1 
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_TOKEN }}
+
+      - name: Build and push
+        uses: docker/build-push-action@v2
+        with:
+          context: .
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}    

.github/workflows/release.yml

@@ -71,13 +71,4 @@ jobs:
           upload_url: ${{ steps.create_release.outputs.upload_url }}
           asset_path: build/sha512sums.txt
           asset_name: sha512sums.txt
-          asset_content_type: application/octet-stream
-      - name: Build and push images
-        uses: docker/build-push-action@v1
-        env:
-          DOCKER_BUILDKIT: "1"
-        with:
-          username: ${{ secrets.DOCKER_USERNAME }}
-          password: ${{ secrets.DOCKER_PASSWORD }}
-          repository: prayagsingh/prometheus-jibri-exporter
-          tags: latest, ${{ github.ref }}
+          asset_content_type: application/octet-stream