Changes to docker workflow

.github/workflows/docker_build.yaml

@@ -1,8 +1,11 @@
-# Test that the docker file builds correctly
+# Build and push latest docker image on push to master branch
 
-name: Docker
+name: Docker Build
 
-on: ["push", "pull_request"]
+on:
+  push:
+    branches:
+      - 'master'
 
 jobs:
   
@@ -10,7 +13,19 @@ jobs:
     runs-on: ubuntu-latest
 
     steps:
-      - uses: actions/checkout@v2
-      - name: Build Docker Image
-        run: cd docker && docker build . --tag inventree:$(date +%s)
-      
+      - name: Checkout Code
+        uses: actions/checkout@v2
+      - name: Login to Dockerhub
+        uses: docker/login-action@v1
+        with:
+          username: ${{ secrets.DOCKER_USERNAME }}
+          password: ${{ secrets.DOCKER_PASSWORD }}
+      - name: Build and Push
+        uses: docker/build-push-action@v2
+        with:
+          context: ./docker
+          push: true
+          repository: inventree/inventree
+          tags: inventree/inventree:latest
+      - name: Image Digest
+        run: echo ${{ steps.docker_build.outputs.digest }}