stagger the default surrogate-key by language (#33202)

.github/workflows/azure-prod-build-deploy.yml

@@ -143,13 +143,6 @@ jobs:
         run: |
           az webapp deployment slot swap --slot canary --target-slot production -n ghdocs-prod -g docs-prod
 
-      - name: Purge Fastly edge cache
-        env:
-          FASTLY_TOKEN: ${{ secrets.FASTLY_TOKEN }}
-          FASTLY_SERVICE_ID: ${{ secrets.FASTLY_SERVICE_ID }}
-          FASTLY_SURROGATE_KEY: 'every-deployment'
-        run: npm install got && .github/actions-scripts/purge-fastly-edge-cache.js
-
   send-slack-notification-on-failure:
     needs: [azure-prod-build-and-deploy]
     runs-on: ubuntu-latest

.github/workflows/purge-fastly.yml

@@ -0,0 +1,55 @@
+name: Purge Fastly
+
+# **What it does**: Sends a soft-purge to Fastly.
+# **Why we have it**: So that, right after a production deploy, we start afresh
+# **Who does it impact**: Writers and engineers.
+
+on:
+  workflow_dispatch:
+    inputs:
+      nuke_all:
+        description: "Nuke all 'every-deployment' keys independent of language"
+        required: false
+        type: boolean
+        default: false
+      languages:
+        description: "Comma separated languages. E.g. 'en,ja, es' (defaults to all)"
+        required: false
+        default: ''
+  workflow_run:
+    workflows: ['Azure Production - Build and Deploy']
+    types:
+      - completed
+
+permissions:
+  contents: read
+
+env:
+  FASTLY_TOKEN: ${{ secrets.FASTLY_TOKEN }}
+  FASTLY_SERVICE_ID: ${{ secrets.FASTLY_SERVICE_ID }}
+
+jobs:
+  send-purges:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@dcd71f646680f2efd8db4afa5ad64fdcba30e748
+
+      - name: Setup node
+        uses: actions/setup-node@17f8bd926464a1afa4c6a11669539e9c1ba77048
+        with:
+          node-version: '16.17.0'
+          cache: npm
+
+      - name: Install dependencies
+        run: npm ci
+
+      - name: Purge Fastly edge cache independent of language
+        if: ${{ github.event.inputs.nuke_all }}
+        run: .github/actions-scripts/purge-fastly-edge-cache.js
+
+      - name: Purge Fastly edge cache per language
+        if: ${{ !github.event.inputs.nuke_all }}
+        env:
+          LANGUAGES: ${{ github.event.inputs.languages }}
+        run: .github/actions-scripts/purge-fastly-edge-cache-per-language.js