Fix Docker Buildx update reruns

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
Copilot-Session: 548ba3f7-0d56-4966-ad57-1b9ace7534f6

.github/workflows/docker-buildx-upgrade.yml

@@ -51,7 +51,20 @@ jobs:
           current_version=$(grep "ARG BUILDX_VERSION=" ./images/Dockerfile | cut -d'=' -f2)
 
           # Fetch latest Buildx version
-          latest_version=$(curl -s https://api.github.com/repos/docker/buildx/releases/latest | jq -r '.tag_name' | sed 's/^v//')
+          latest_response=$(curl -fsSL https://api.github.com/repos/docker/buildx/releases/latest) || {
+            echo "Failed to retrieve Buildx release information"
+            exit 1
+          }
+          latest_version=$(jq -er '.tag_name | sub("^v"; "")' <<< "$latest_response") || {
+            echo "Failed to retrieve a valid Buildx version"
+            exit 1
+          }
+
+          # Extra check to ensure we got a valid version
+          if [[ ! $latest_version =~ ^[0-9]+\.[0-9]+\.[0-9]+$ ]]; then
+            echo "Failed to retrieve a valid Buildx version"
+            exit 1
+          fi
 
           should_update=false
           [ "$current_version" != "$latest_version" ] && should_update=true
@@ -91,6 +104,12 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v7
 
+      - name: Create update branch
+        shell: bash
+        run: |
+          branch_name="feature/docker-buildx-upgrade"
+          git checkout -B "$branch_name"
+
       - name: Update Docker version
         if: ${{ needs.check-versions.outputs.DOCKER_SHOULD_UPDATE == 'true' }}
         shell: bash
@@ -141,14 +160,6 @@ jobs:
           git config --global user.name "github-actions[bot]"
           git config --global user.email "<41898282+github-actions[bot]@users.noreply.github.com>"
 
-          # Create branch or switch to it if it exists
-          if git show-ref --quiet refs/remotes/origin/$branch_name; then
-            git fetch origin
-            git checkout -B "$branch_name" origin/$branch_name
-          else
-            git checkout -b "$branch_name"
-          fi
-
           # Commit and push changes
           git commit -a -m "$commit_message"
           git push --force origin "$branch_name"
@@ -185,11 +196,15 @@ jobs:
             echo "Autogenerated by [Docker/Buildx Version Upgrade Workflow](https://github.com/actions/runner/blob/main/.github/workflows/docker-buildx-upgrade.yml)"
           } > pr_body.txt
 
-          # Create PR
-          gh pr create -B main -H "$branch_name" \
-            --title "$pr_title" \
-            --label "dependencies" \
-            --label "dependencies-weekly-check" \
-            --label "dependencies-not-dependabot" \
-            --label "docker" \
-            --body-file pr_body.txt
+          existing_pr=$(gh pr list --head "$branch_name" --state open --json number --jq '.[0].number // ""')
+          if [[ -n "$existing_pr" ]]; then
+            gh pr edit "$existing_pr" --title "$pr_title" --body-file pr_body.txt
+          else
+            gh pr create -B main -H "$branch_name" \
+              --title "$pr_title" \
+              --label "dependencies" \
+              --label "dependencies-weekly-check" \
+              --label "dependencies-not-dependabot" \
+              --label "docker" \
+              --body-file pr_body.txt
+          fi