add script to generate changelog for a PR

Makefile

@@ -619,6 +619,13 @@ envoy-regen: ## Regenerating envoy golden files
 	@find "command/connect/envoy/testdata" -name '*.golden' -delete
 	@go test -tags '$(GOTAGS)' ./command/connect/envoy -update
 
+
+##@ Changelog
+
+.PHONY: gen-changelog
+gen-changelog: ## Generate changelog entry for the current branch based on the currently open PR for that branch
+	@$(SHELL) $(CURDIR)/build-support/scripts/gen-changelog.sh
+
 ##@ Help
 
 # The help target prints out all targets with their descriptions organized

build-support/scripts/gen-changelog.sh

@@ -0,0 +1,56 @@
+#! /bin/bash
+
+set -eo pipefail
+
+pr_number=$(gh pr list -H "$(git rev-parse --abbrev-ref HEAD)" --json "number" | jq ".[].number")
+
+# create a new changelog file
+touch ".changelog/$pr_number.txt"
+
+echo "Created a new changelog file for PR $pr_number."
+
+# prompt user to pick from list of types of changlog from "breaking-change", "security", "feature", "deprecation", or "bug"
+echo "Please select the type of change:"
+echo "1. breaking-change"
+echo "2. security"
+echo "3. feature"
+echo "4. deprecation"
+echo "5. bug"
+
+if [ -z "$1" ]; then
+  read -p "Enter your choice: " choice
+else
+  choice=$1
+fi
+
+type=""
+
+case $choice in
+1)
+  type="breaking-change"
+  ;;
+2)
+  type="security"
+  ;;
+3)
+  type="feature"
+  ;;
+4)
+  type="deprecation"
+  ;;
+5)
+  type="bug"
+  ;;
+*)
+  echo "Invalid choice. Please select a number from 1 to 5."
+  exit 1
+  ;;
+esac
+
+msg=""
+
+read -ep $'Please enter the changelog message:\n' msg
+
+echo -e "\`\`\`release-note:$type\n$msg\n\`\`\`" >>".changelog/$pr_number.txt"
+
+cat .changelog/$pr_number.txt