workflows: add hostname duplicate check

.github/checks/check-hostname-duplicates.sh

@@ -0,0 +1,29 @@
+#!/bin/bash
+
+# Change to the locations directory
+cd locations || exit 1
+
+# Variable to accumulate duplicate findings
+all_duplicates=""
+
+# Iterate over each file in the directory
+for file in ./*; do
+  # Check if it is a file
+  if [ -f "$file" ]; then
+    # Extract hostnames, sort, and find duplicates
+    duplicates=$(sed -nE 's/^\s*-\s*hostname:\s*["'\'']{0,1}([a-zA-Z0-9-]+)["'\''#]?([\s].*)?$/\1/p' "$file" | sort | uniq -cd)
+
+    # Accumulate duplicates if found
+    if [ -n "$duplicates" ]; then
+      all_duplicates+="\n$duplicates"
+    fi
+  fi
+done
+
+# Check if there were any duplicates found
+if [ -n "$all_duplicates" ]; then
+  echo -e "Duplicate hostnames found:$all_duplicates"
+  exit 1
+else
+  echo "No duplicate hostnames found."
+fi

.github/workflows/check-hostname-duplicates.yml

@@ -0,0 +1,17 @@
+---
+name: Check for duplicate hostnames
+
+on: [push, pull_request]  # yamllint disable-line rule:truthy
+
+jobs:
+  check-hostname-duplicates:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Run hostname duplicate check
+        run: |
+          ./.github/checks/check-hostname-duplicates.sh