adding the script to validate changelog

Signed-off-by: ntishchauhan0022 <nitishchauhan0022@gmail.com>

.github/workflows/pr-validation.yml

@@ -148,3 +148,11 @@ jobs:
       output: ''
       exit-code: 1
       publish: false
+
+  validateChangelog:
+    name: Validate changelog
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Validate changelog
+        run: make validate-changelog

Makefile

@@ -363,3 +363,7 @@ help: ## Display this help.
 .PHONY: docker-build-dev-containers
 docker-build-dev-containers: ## Build dev-containers image
 	docker build -f .devcontainer/Dockerfile .
+
+.PHONY: validate-changelog
+validate-changelog: ## Validate changelog
+	./hack/validate-changelog.sh

hack/validate-changelog.sh

@@ -0,0 +1,53 @@
+#!/bin/bash
+
+SCRIPT_ROOT=$(dirname "${BASH_SOURCE[0]}")/..
+
+# Define filename
+filename="$SCRIPT_ROOT/CHANGELOG.md"
+
+# Check if file exists
+if [[ ! -f "$filename" ]]; then
+    echo "Error: $filename does not exist."
+    exit 1
+fi
+
+# Read content between "## Unreleased" and "## v" into variable
+unreleased=$(awk '/## Unreleased/{flag=1;next}/## v[0-9\.]+/{flag=0}flag' "$filename")
+
+# Check if "Unreleased" section exists
+if [[ -z "$unreleased" ]]; then
+    echo "Error: No 'Unreleased' section found in $filename."
+    exit 1
+fi
+
+# Define a function to extract and sort sections
+function extract_and_check() {
+  local section=$1
+  local content=$(awk "/### $section/{flag=1;next}/### /{flag=0}flag" <<< "$unreleased" | grep '^- \*\*') 
+
+  # Skip if content does not exist
+  if [[ -z "$content" ]]; then
+    return
+  fi
+
+  local sorted_content=$(echo "$content" | sort)
+
+  # Check pattern and throw error if wrong pattern found
+  echo "$content" | grep -Pv '^(-\s\*\*[^*]+\*\*: .*\(\[#(\d+)\]\(https:\/\/github\.com\/kedacore\/keda\/(pull|issues)\/\2\)\))$' | while read -r line ; do
+    echo "Error: Wrong pattern found in $section section, line: $line"
+    exit 1
+  done
+
+  if [ "$content" != "$sorted_content" ]; then
+      echo "Error: The $section section is not sorted correctly. Correct order:"
+      echo "$sorted_content"
+      exit 1
+  fi
+}
+
+# Separate content into different sections and check sorting
+extract_and_check "New"
+extract_and_check "Improvements"
+extract_and_check "Fixes"
+extract_and_check "Deprecations"
+extract_and_check "Other"