Bash command in ubuntu to create a bare git repo and post commit hooks to start node js with pm2

create-bare-repo.sh

#!/bin/bash

# USAGE:
# command   example.com    [OPTIONS]
#
#           args            desc
#           example.com     the domain name
#
#           options               args              desc
#               --app-name        short-app-name    required if --pm2-start is yes
#               --domain-name     domain-name
#               --npm-install     yes|no            include npm install script in post hooks or not
#               --npm-build       yes|no            include npm run build in post hooks or not
#               --pm2-start       yes|no            include pm2 start script in post hooks or not
#           -p  --port            3000              required if --pm2-start option is yes
#           -?                                      show this help
#           -h  --help                              show this help
# example:
# > command example.com --npm-install yes --pm2-start no
#
# or
# > command example.com --pm2-start=yes --app-name=something --port 3000
#
# or
# > command --domain-name=example.com --npm-install no

# ## VARIABLES
domainName=
appName=
isUseNPM=
isUseNPMBuild=
isUsePM2=
port=

gitDir=
gitWorkTreeDir=
postHooksFile=
postHooksScript=

pm2ConfigFile=
pm2ConfigScript=

# exit and show error
function Die() {
	echo "$1\n" >&2
	printf "$s\n" "$1" >&2
	exit 1
}

# show usage
function ShowHelp() {
	cat <<-EOF
		Usage for $0:
		command   example.com    [OPTIONS]
		            
		          args            desc
		          example.com     the domain name
		            
		          options             args              desc
		              --app-name      short-app-name    required if --pm2-start is yes
		              --domain-name   domain-name
		              --npm-install   yes|no            include npm install script in post hooks or not
		              --npm-build     yes|no            include npm run build in post hooks or not
		              --pm2-start     yes|no            include pm2 start script in post hooks or not
		          -p  --port          3000              required if --pm2-start option is yes
		          -?                  show this help
		          -h  --help                            show this help
		example:
		> command example.com --npm-install yes --npm-build yes --pm2-start no

		or
		> command example.com --pm2-start=yes --app-name=something --port 3000

		or
		> command --domain-name=example.com --npm-install no
	EOF
}

# ## first argument
if [ "$1" ] && [[ "$1" != -* ]]; then # if first arg exist and not starts with -, assign domain name
	domainName=$1
	shift
fi

# ## option argument
if [ $# -gt 0 ]; then
	while [ "$1" ]; do
		case $1 in
		--app-name)
			# set app name
			# if argument exist, set app name, else ask user input
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					appName=$2
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--app-name=?*)
			# get argument after "=" sign
			appName=${1#*=}
			shift
			;;
		--app-name=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		--domain-name)
			# set domain name
			# if domain name is not null
			if [ "$domainName" ]; then
				echo "Warning: redeclared domain name using \"$1\" option"
			fi
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					domainName=$2
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--domain-name=?*)
			# get argument after "=" sign
			domainName=${1#*=}
			shift
			;;
		--domain-name=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		--npm-install)
			# include or exclude npm install
			echo "npm install case"
			[[ "$2" == -* ]] && echo "ok"
			
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					if [ "$2" = "yes" ]; then
						isUseNPM="include npm"
					elif [ "$2" = "no" ]; then
						isUseNPM="exclude npm"
					fi
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--npm-install=?*)
			# get argument after "=" sign
			if [ "${1#*=}" = "yes" ]; then
				isUseNPM="include npm"
			elif [ "${1#*=}" = "no" ]; then
				isUseNPM="exclude npm"
			fi
			shift
			;;
		--npm-install=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		--npm-build)
			# include or exclude npm run build
			echo "npm run build case"
			[[ "$2" == -* ]] && echo "ok"
			
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					if [ "$2" = "yes" ]; then
						isUseNPMBuild="include npm run build"
					elif [ "$2" = "no" ]; then
						isUseNPMBuild="exclude npm run build"
					fi
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--npm-build=?*)
			# get argument after "=" sign
			if [ "${1#*=}" = "yes" ]; then
				isUseNPMBuild="include npm run build"
			elif [ "${1#*=}" = "no" ]; then
				isUseNPMBuild="exclude npm run build"
			fi
			shift
			;;
		--npm-build=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		--pm2-start)
			# include or exclude pm2 start script
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					if [ "$2" = "yes" ]; then
						isUsePM2="include pm2"
					elif [ "$2" = "no" ]; then
						isUsePM2="exclude pm2"
					fi
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--pm2-start=?*)
			# get argument after "=" sign
			if [ "${1#*=}" = "yes" ]; then
				isUsePM2="include pm2"
			elif [ "${1#*=}" = "no" ]; then
				isUsePM2="exclude pm2"
			fi
			shift
			;;
		--pm2-start=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		--port)
			# set port in pm2 config
			if [ "$2" ]; then
				if [[ "$2" == -* ]]; then
					Die "Error: argument cannot start with \"-\" for option \"$1\""
				else
					port=$2
					shift 2
				fi
			else
				Die "Error: argument required for \"$1\" option"
			fi
			;;
		--port=?*)
			# get argument after "=" sign
			port=${1#*=}
			shift
			;;
		--port=)
			# empty args
			Die "Error: argument required for \"$1\" option"
			;;
		-h | -\? | --help)
			# display usage
			ShowHelp
			shift
			exit
			;;
		*)
			# unrecognized argument
			Die "Error: \"$1\" is not recognized as an argument or option"
			;;
		esac
	done
fi

# ## check required user input when argument not specified
# ## and set variables
while [ ! "$domainName" ]; do
	read -p "*Provide domain name: (domain.com) " domainName

done

if [ "$domainName" ]; then
	gitDir=${HOME}/repo/node/${domainName}.git
	gitWorkTreeDir=${HOME}/source/node/${domainName}
	postHooksFile=${gitDir}/hooks/post-receive
	postHooksScript=$(
		cat <<-EOF
			#!/bin/sh
			git --work-tree=$gitWorkTreeDir --git-dir=$gitDir checkout -f main
		EOF
	)
fi

while [ ! "$isUseNPM" ]; do
	read -p "*Include npm install? (yes/no) " isUseNPM
	if [ "$isUseNPM" = "yes" ]; then
		isUseNPM="include npm"

	elif [ "$isUseNPM" = "no" ]; then
		isUseNPM="exclude npm"
	else
		isUseNPM=
	fi
done

if [ "$isUseNPM" = "include npm" ]; then
	# append npm script to post receive hook
	postHooksScript+=$(
		cat <<-EOF

			echo "export nvs path"
			export PATH=\$PATH:${HOME}/.nvs/default/bin

			echo "changing directory"
			cd ${gitWorkTreeDir}

			echo "installing dependencies"
			npm install
		EOF
	)
fi

while [ ! "$isUseNPMBuild" ]; do
	read -p "*Include npm run build? (yes/no) " isUseNPMBuild
	if [ "$isUseNPMBuild" = "yes" ]; then
		isUseNPMBuild="include npm run build"

	elif [ "$isUseNPMBuild" = "no" ]; then
		isUseNPMBuild="exclude npm run build"
	else
		isUseNPMBuild=
	fi
done

if [ "$isUseNPMBuild" = "include npm run build" ]; then
	# append npm run build script to post receive hook
	postHooksScript+=$(
		cat <<-EOF

			echo "building project"
			npm run build
		EOF
	)
fi



while [ ! "$isUsePM2" ]; do
	read -p "*Include pm2 start script? (yes/no) " isUsePM2
	if [ "$isUsePM2" = "yes" ]; then
		isUsePM2="include pm2"

		while [ ! "$appName" ]; do
			read -p "*Provide app name: (app-name) " appName
		done

		while [ ! "$port" ]; do
			read -p "*Provide port number: (5000-5999) " port
		done

	elif [ "$isUsePM2" = "no" ]; then
		isUsePM2="exclude pm2"
	else
		isUsePM2=
	fi
done

if [ "$isUsePM2" = "include pm2" ]; then
	# add pm2 config
	pm2ConfigFile=${HOME}/source/node/ecosystem.config.js
	pm2ConfigScript=$(
		cat <<-EOF
			    {\
			\n      name: "${appName}",\
			\n      script: "npm",\
			\n      args: "run start",\
			\n      cwd: "./${domainName}",\
			\n      watch: true,\
			\n      ignore_watch: ["node_modules"],\
			\n      restart_delay: 1000,\
			\n      env: {\
			\n        PORT: $port,\
			\n      },\
			\n    },
		EOF
	)

	# check if file exist and is not empty
	if [ -f "$pm2ConfigFile" ] && [ -s "$pm2ConfigFile" ]; then
		# get line position
		ln=$(($(cat $pm2ConfigFile | wc -l) - 1))
	else
		ln=3
		cat <<-EOF >$pm2ConfigFile
			module.exports = {
			  apps: [
			  ],
			}
		EOF
	fi

	# insert pm2ConfigScript object string into array string in pm2ConfigFile
	# in the correct line position
	pm2ConfigScript=$(sed "${ln}i\\$pm2ConfigScript" $pm2ConfigFile)

	# append pm2 script to post receive hook
	postHooksScript+=$(
		cat <<-EOF

			echo "set up and start from pm2 config file"
			cd ${HOME}/source/node/
			pm2 stop ${appName} || : && pm2 delete ${appName} || : && pm2 start ecosystem.config.js --only ${appName}
			pm2 save

			echo "completed"
		EOF
	)
fi

# main script
# create dirs
mkdir -p $gitDir $gitWorkTreeDir
# init git bare repo
if cd $gitDir; then
	git init --bare --quiet
else
	echo "failed changing directory to: $gitDir" >&2
	echo "exit before running \"git init --bare\" and the rest of process" >&2
	exit 1
fi
# create post-receive hooks and set executable
echo "$postHooksScript" >$postHooksFile
chmod +x $postHooksFile
# create copy of previous pm2 config
cp $pm2ConfigFile $pm2ConfigFile.former 2>/dev/null
# create pm2 config app if set
[ "$isUsePM2" = "include pm2" ] && echo "$pm2ConfigScript" >$pm2ConfigFile

# get public ip address
publicIP=$(curl https://ipinfo.io/ip)

# finish, ready to pushed to repo
# output repo link
echo "ssh://${USER}@$publicIP$gitDir"