Bash script to auto-generate release notes.

auto_generate_release_notes.sh

@@ -0,0 +1,118 @@
+#! /bin/sh
+
+###### Script writer: Shivansh Saini (@shivanshs9) [26/10/2018] ######
+
+## Initial Configurations
+REPO_URI="sendgrid/python-http-client"
+GITHUB_USERNAME="sendgrid"
+CHANGELOG_FILE="CHANGELOG.md"
+
+## Helper functions
+get_line_no() {
+	release="$1"
+	grep -n -m 1 "$release" "$CHANGELOG_FILE" | cut -d ":" -f 1
+}
+
+get_current_tag() {
+	git describe --abbrev=0 --tags
+}
+
+get_latest_tag() {
+	curl -s $API_RELEASES_URL"/latest" | python3 -c \
+		"import sys, json; print(json.load(sys.stdin)['tag_name'])" 2>/dev/null
+}
+
+get_body() {
+	current_local_tag="$1"
+	last_deployed_tag="$2"
+	start=$(get_line_no "${current_local_tag:1}")
+	: $(( start++ ))
+	end=$(get_line_no "${last_deployed_tag:1}")
+	: $(( end-- ))
+
+	# Getting the updated content in CHANGELOG.md and making it JSON-safe
+	sed "${start},${end}p" "$CHANGELOG_FILE" -n | sed -z 's/\n/\\n/g'
+}
+
+print_help() {
+	echo -e "\nUsage:"
+	echo -e "\t$0 [options]"
+
+	echo -e "\nDescription:"
+	echo -e "\tA shell utility script to auto-generate release notes of configured repository based \
+on the latest release tag and the current tag. Looks for changes in the configured changelog file."
+
+	echo -e "\nOptions:"
+	options="\t-h, --help|Show help.\n\
+\t-u, --username <username>|Calls the Github API providing username as <username>.\n\
+\t-r, --repository <repo_uri>|Configures the repository to use github <repo_uri>, which is in the format of <owner>/<repo>.\n\
+\t-c, --changelog <file>|Configures to look for <file> for release notes. The release notes should start from\
+the next line of the tag name."
+	echo -e $options | column -t -s '|'
+}
+
+## Main script
+
+while [[ $# -gt 0 ]]; do
+	key="$1"
+	case $key in
+		-u|--username)
+			GITHUB_USERNAME="$2"
+			shift
+			shift
+			;;
+		-r|--repository)
+			REPO_URI="$2"
+			shift
+			shift
+			;;
+		-c|--changelog)
+			CHANGELOG_FILE="$2"
+			shift
+			shift
+			;;
+		-h|--help)
+			print_help
+			exit
+			;;
+		*)
+			echo "Invalid argument. Use $0 --help to get help."
+			exit 2
+			;;
+	esac
+done
+
+API_RELEASES_URL="https://api.github.com/repos/"${REPO_URI}"/releases"
+
+if [[ ! -f "$CHANGELOG_FILE" ]]; then
+	echo "ERROR: \"$CHANGELOG_FILE\" file doesn't exist."
+	exit 1
+fi
+
+echo -n "Getting current release tag..."
+current_local_tag=$(get_current_tag)
+echo " $current_local_tag"
+
+echo -n "Getting latest release tag..."
+last_deployed_tag=$(get_latest_tag)
+echo " $last_deployed_tag"
+
+if [[ -z "$last_deployed_tag" ]]; then
+	echo "ERROR: Unable to find last release tag from \"$REPO_URI.\""
+	exit 1
+fi
+
+if [[ "$last_deployed_tag" = "$current_local_tag" ]]; then
+	echo "SKIPPING: Local tag is up-to-date with the latest release tag."
+	exit
+fi
+
+body=$(get_body "$current_local_tag" "$last_deployed_tag")
+title="$current_local_tag"
+
+echo "----Releasing \"$current_local_tag\" to \"$REPO_URI\"----"
+
+data="{\"tag_name\": \"$current_local_tag\", \"name\": \"$title\", \"body\": \"$body\"}"
+
+curl -s -X POST -H "Content-Type:application/json" -u "$GITHUB_USERNAME" \
+"$API_RELEASES_URL" --data-binary @- <<<$data