add github action to trigger load tests based on PR label

.github/workflows/load-test.yml

@@ -0,0 +1,63 @@
+on:
+  pull_request:
+    branches:
+      - master
+    types: [labeled]
+
+jobs:
+  trigger-load-test:
+    if: ${{ github.event.label.name == 'test/load' }}
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v2
+        with:
+          ref: ${{ github.event.pull_request.head.sha }}
+      - name: Trigger CircleCI Load Test Pipeline
+        run: |
+          # build json payload to trigger CircleCI Load Test Pipeline
+          # This only runs the load test pipeline on the 'master' branch
+          jsonData=$(jq --null-input -r --arg commit ${{ github.event.pull_request.head.sha }} \
+            '{branch:"master", parameters: {"commit": $commit, "trigger-load-test": true}}')
+          echo "Passing JSON data to CircleCI API: $jsonData"
+          load_test_pipeline_id=$(curl -X POST \
+               -H "Circle-Token: ${{ secrets.CIRCLE_TOKEN }}" \
+               -H "Content-Type: application/json" \
+               -d "$jsonData" \
+              "https://circleci.com/api/v2/project/gh/${GITHUB_REPOSITORY}/pipeline" | jq -r '.id')
+          echo "LOAD_TEST_PIPELINE_ID=$load_test_pipeline_id" >> $GITHUB_ENV
+      - name: Post Load Test URL to PR
+        env:
+          PR_COMMENT_URL: ${{ github.event.pull_request.comments_url }}
+        run: |
+          echo "LOAD_TEST_PIPELINE_ID is: $LOAD_TEST_PIPELINE_ID"
+          # get load-test workflow
+          workflow=
+          # wait up to a minute for load-test workflow to start
+          until [ $SECONDS -ge 60 ] && exit 1; do
+            workflow=$(curl -s -X GET \
+                -H "Circle-Token: ${{ secrets.CIRCLE_TOKEN }}" \
+                -H "Content-Type: application/json" \
+                "https://circleci.com/api/v2/pipeline/${LOAD_TEST_PIPELINE_ID}/workflow" | jq '.items[] | select(.name=="load-test")')
+            # if we found a workflow we exit
+            if [ -n "$workflow" ]; then
+              break
+            fi
+            echo -n "."
+            sleep 5
+          done
+          echo "$workflow"
+          # get pipeline number
+          pipeline_number=$(echo "$workflow" | jq -r '.pipeline_number')
+          # get workflow id
+          workflow_id=$(echo "$workflow" | jq -r '.id')
+          # get project slug
+          project_slug=$(echo "$workflow" | jq -r '.project_slug')
+          # build load test URL
+          load_test_url="https://app.circleci.com/pipelines/${project_slug}/${pipeline_number}/workflows/${workflow_id}"
+          # comment URL to pull request
+          curl -X POST \
+               -H "Authorization: token ${{ secrets.PR_COMMENT_TOKEN }}" \
+               -H "Content-Type: application/json" \
+               -d "{\"body\": \"Load Test Pipeline Started at: $load_test_url\"}" \
+              "$PR_COMMENT_URL"