new workflow

pushes / pulls on main will trigger the built of a docker container, which will be uploaded to ttubb/submg on dockerhub

.github/workflows/container.yml

@@ -0,0 +1,28 @@
+name: Build and Push Docker Image
+
+on:
+  push:
+    branches: [ "main" ]
+  pull_request:
+    branches: [ "main" ]
+
+jobs:
+  build-and-push:
+    runs-on: ubuntu-latest
+    steps:
+    - name: Check out code
+      uses: actions/checkout@v2
+
+    - name: Log in to Docker Hub
+      uses: docker/login-action@v1
+      with:
+        username: ${{ secrets.DOCKER_USERNAME }}
+        password: ${{ secrets.DOCKER_PASSWORD }}
+
+    - name: Build and push Docker image
+      uses: docker/build-push-action@v2
+      with:
+        context: ./docker
+        file: ./docker/Dockerfile
+        push: true
+        tags: ttubb/submg:latest # You can also use other tags or versioning schemes