Add configuration files for static web app with global headers (#2968)

This pull request introduces a new workflow step to automatically merge
environment-specific configuration files for static web apps during the
build process. It also adds initial configuration files for different
deployment environments, enabling environment-based customization of
global HTTP headers.

**Workflow automation:**

* Added a "Merge Configuration Files" step to
`.github/workflows/main.yml` that locates and merges
environment-specific `staticwebapp.*.json` files using `jq`, producing a
unified `staticwebapp.config.json` for deployment. This step includes
error handling and debug output for easier troubleshooting.

**Environment-specific configuration:**

* Added `staticwebapp.config.canary.json` as a placeholder for canary
environment configuration in `docs/static/`.
* Added `staticwebapp.config.preview.json` with global HTTP headers for
CORS, allowing requests from `https://devopsmigration.io` in the preview
environment.
* Added `staticwebapp.config.production.json` with global HTTP headers
for CORS, allowing requests from the production Azure static app domain.

Author: MrHinsh

.github/workflows/main.yml

@@ -670,6 +670,67 @@ jobs:
         with:
           name: AzureDevOpsMigrationTools-Site2
           path: ./_site2
+
+      - name: Merge Configuration Files
+        run: |
+          # Find all files matching the pattern in a safe way
+          $files = Get-ChildItem -Path "." -Recurse -Filter "staticwebapp.*.json" -ErrorAction Stop
+
+          if ($files.Count -eq 0) {
+              Write-Host "No files matching the pattern 'staticwebapp.*.json' were found."
+              exit 1
+          }
+
+          # Output each file's full name (for verification/debugging purposes)
+          $files | ForEach-Object {
+              Write-Host "Found file: $($_.FullName)"
+          }
+
+          # Paths to main and environment-specific config files
+          $environment = ("${{ (needs.Setup.outputs.nkdAgility_Ring) }}").ToLower()
+          $rootConfig = "./_site2/staticwebapp.config.json"
+          $environmentConfig = "./_site2/staticwebapp.config.$environment.json"
+
+          # Check if both target files exist
+          if ((Test-Path -Path $rootConfig -ErrorAction Stop) -and (Test-Path -Path $environmentConfig -ErrorAction Stop)) {
+              try {
+                  # Run jq to merge files and capture the output
+                  $mergedContent = & jq -s 'reduce .[] as $item ({}; . * $item)' $rootConfig $environmentConfig # $routesConfig
+
+                  if ($mergedContent -ne "") {
+                      # Write the merged content to the output file
+                      $mergedContent | Set-Content -Path "./_site2/staticwebapp.config.json"
+                      Write-Host "Merged JSON files successfully."
+                  }
+                  else {
+                      Write-Host "jq command produced empty output. Check JSON structures in input files."
+                      exit 1
+                  }
+              }
+              catch {
+                  Write-Host "Error merging JSON files with jq: $_"
+                  exit 1
+              }
+          }
+          else {
+              Write-Host "One or both of the specified config files were not found:"
+              if (!(Test-Path -Path $rootConfig)) { Write-Host " - $rootConfig not found" }
+              if (!(Test-Path -Path $environmentConfig)) { Write-Host " - $environmentConfig not found" }
+              exit 1
+          }
+
+          # Verify and read the merged file content
+          try {
+              $content = Get-Content -Path "./_site2/staticwebapp.config.json" -ErrorAction Stop
+              Write-Host "Content of merged config file:"
+              Write-Output $content
+          }
+          catch {
+              Write-Host "Error reading the merged config file: $_"
+              exit 1
+          }
+
+
       - name: "Find  files"
         shell: pwsh
         run: |

docs/static/staticwebapp.config.canary.json

@@ -0,0 +1,2 @@
+{
+}

docs/static/staticwebapp.config.json

@@ -1,5 +1,13 @@
 {
   "routes": [
+    {
+      "route": "/version.json",
+      "headers": {
+        "Access-Control-Allow-Origin": "*",
+        "Access-Control-Allow-Methods": "GET, OPTIONS",
+        "Access-Control-Allow-Headers": "Content-Type"
+      }
+    }
   ],
   "responseOverrides": {
     "404": {

docs/static/staticwebapp.config.preview.json

@@ -0,0 +1 @@
+{}

docs/static/staticwebapp.config.production.json

@@ -0,0 +1,2 @@
+{
+}