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docs/github-actions/build-publish-container.md

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+# Build and Publish a Docker Image
+
+This action builds and publishes a Docker image to a container registry. For most of my projects I use DockerHub, but you could use this action and tweak it to use any container registry.
+
+For publish docker images I usually restrict this to the `main` branch, however as this step is often just part of the CI pipeline, you will need some conditional logic to ensure the image is only published on the `main` branch (and not when the build is triggered by a `feature/*` or `fix/*` branch).
+
+## Minimal Pipeline Example
+
+```yaml
+name: Build, Test & Publish
+
+on:
+  push:
+    branches:
+    - main
+    - feature/*  
+    - fix/*
+  pull_request:
+    branches:
+    - main
+
+jobs:
+  publish:
+    if: github.ref == 'refs/heads/main' && github.event_name == 'push'
+    name: Build and Publish Container Image
+    runs-on: ubuntu-latest
+    
+    needs:
+    - build
+
+    steps:
+    - uses: actions/checkout@v3
+  
+    - name: Setup Docker Metadata
+      id: meta
+      uses: docker/metadata-action@v4
+      with:
+          images: your-username/your-project
+          tags: |
+            type=raw,value=latest
+
+    - name: Login to DockerHub
+      uses: docker/login-action@v3
+      with:
+        username: ${{ secrets.DOCKER_USERNAME }}
+        password: ${{ secrets.DOCKER_TOKEN }}
+
+    - name: Build and Push Docker Image to DockerHub
+      uses: docker/build-push-action@v4 
+      with:
+        file: './path/to/project/Dockerfile'
+        context: ./path/to/project
+        push: true
+        tags: ${{ steps.meta.outputs.tags }}
+        labels: ${{ steps.meta.outputs.labels }}
+```
+
+In the above pipeline a few changes will need to be made to suit the project you are working on:
+* In the setup docker metadata step, update the `images` to your DockerHub username and the name of your project.
+* In the build and push docker image step, update the `file` to the path of your Dockerfile, and the `context` to the path of your project.
+* You will also need to add your docker username and docker token to your GitHub repository secrets. The `DOCKER_USERNAME` is your DockerHub username, and the `DOCKER_TOKEN` is a token generated from DockerHub.