Adding docker publish workflow

.github/workflows/publish_docker.yml

@@ -0,0 +1,74 @@
+name: perfSONAR pSConfig Image
+
+# This action builds Docker images then 
+# pushes result to GitHub Container Registry.
+
+on:
+  push:
+    branches: [ '*' ]
+    # Publish semver tags as releases.
+    tags: [ 'v*.*.*' ]
+  pull_request:
+    branches: [ 'main' ]
+
+env:
+  REGISTRY: ghcr.io
+  # github.repository as <account>/<repo>
+  IMAGE_BASE: ${{ github.repository }}
+  BUILD_DIR: .
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      packages: write
+      # This is used to complete the identity challenge
+      # with sigstore/fulcio when running outside of PRs.
+      id-token: write
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v3
+
+      - name: Set up QEMU
+        uses: docker/setup-qemu-action@v2
+
+      - name: Setup Docker buildx
+        uses: docker/setup-buildx-action@v2
+
+      # Login against a Docker registry except on PR
+      # https://github.com/docker/login-action
+      - name: Log into registry ${{ env.REGISTRY }}
+        if: github.event_name != 'pull_request'
+        uses: docker/login-action@v2
+        with:
+          registry: ${{ env.REGISTRY }}
+          username: ${{ github.actor }}
+          password: ${{ secrets.GITHUB_TOKEN }}
+
+      # Extract metadata (tags, labels) for Docker
+      # https://github.com/docker/metadata-action
+      - name: Extract Docker metadata
+        id: meta
+        uses: docker/metadata-action@98669ae865ea3cffbcbaa878cf57c20bbf1c6c38
+        with:
+          images: ${{ env.REGISTRY }}/${{ env.IMAGE_BASE }}
+          tags: |
+            type=schedule
+            type=ref,event=branch
+            type=ref,event=tag
+            type=ref,event=pr
+            type=raw,value=latest,enable=${{ github.ref == format('refs/heads/{0}', 'main') }}
+
+      # Build and push Docker image with Buildx (don't push on PR)
+      # https://github.com/docker/build-push-action
+      - name: Build and push Docker images
+        id: build-and-push
+        uses: docker/build-push-action@v3
+        with:
+          context: ${{ env.BUILD_DIR }}
+          file: ${{ env.BUILD_DIR }}/Dockerfile
+          push: ${{ github.event_name != 'pull_request' }}
+          tags: ${{ steps.meta.outputs.tags }}
+          labels: ${{ steps.meta.outputs.labels }}