Add a github-action to build and publish on docker hub.

Author: philippe-cbw

.github/workflows/main.yml

@@ -0,0 +1,28 @@
+name: Publish Docker image
+
+on:
+  push:
+    branches:
+      - main
+
+jobs:
+  push_to_registries:
+    name: Push Docker image
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out the repo
+        uses: actions/checkout@v4
+
+      - name: Log in to Docker Hub
+        uses: docker/login-action@v3
+        with:
+          username: ${{ secrets.DOCKERHUB_USERNAME }}
+          password: ${{ secrets.DOCKERHUB_PASSWORD }}
+
+      - name: Build and push Docker images
+        id: push
+        uses: docker/build-push-action@v6
+        with:
+          context: .
+          push: true
+          tags: cyberwatch/snmp-emulator:latest