prepare

#!/bin/bash - 
#===============================================================================
#
#          FILE: prepare
# 
#         USAGE: ./prepare -i <app-name> -r /opt -u 
#                ./prepare -i <app-name> -r /opt
#                ./prepare -i <app-name>
#                ./prepare -f 
# 
#   DESCRIPTION: Initialize an aviumlabs Phoenix Framework docker project with
#                database support 
#       OPTIONS: ---
#  REQUIREMENTS: ---
#          BUGS: ---
#         NOTES: The Avium Labs Phoenix Framework docker project is setup
#                as a multi-stage process. 
#                First stage:
#                  Initialize Phoenix Framework project
#                Second stage:
#                  Configure dev.exs for docker
#                  Configure .env for app
#        AUTHOR: Michael Konrad (2023), 
#  ORGANIZATION: Avium Labs LLC 
#       CREATED: 04/05/2023 10:42
#      REVISION:  ---
#===============================================================================

set -o nounset                              # Treat unset variables as an error
IFS=$'\n\t'

# Defaults
ENV_FILE=$(pwd)/.env
DB_SECRET_FILE=$(pwd)/.secret_db
APP_CONTAINER_ROOT=/opt
MIX_ENV=dev                                 # dev, test, prod

# Help 
usage() {
	printf "\n"
	printf "A script to automate the steps to configure the\n"
	printf "docker containers based on this docker compose file.\n"
	printf "\n"
	printf "Project preparation is a two step process: \n"
	printf "Step 1: Initialize Phoenix Framework project docker root and\n" 
	printf "        the application name.\n"
	printf "\n"
	printf "Step 2: Finalize the Phoenix Framework project, run\n"
	printf "        ecto.create, and docker compose up.\n"
	printf "\n"
	printf "$0 -i <app_name> [-r </app/container/root>] [-u]\n"
	printf "$0 -f\n"
	printf "\n Details: \n"
	printf "           -i specify the name of the application.\n"
	printf "           -r optionally specify the application's container root\n"
	printf "              directory, defaults to /opt.\n"
	printf "           -u optionally specify this application is configured as\n"
	printf "              a Phoneix umbrella application.\n" 
	printf "           -f finalize the Phoenix Framework project,\n"
	printf "              updates the config/dev.exs file and the\n"
	printf "              docker environment file.\n"
	printf "\n"
	printf " This script by default generates the docker environment \n"
	printf " file, as .env file in the current working directory.\n"
        printf "\n\n"
        printf "Initialize example:\n" 
	printf "  * $0 -i gutentag -r /opt -u\n"
	printf "  * $0 -i gutentag -r /app\n"
	printf "  * $0 -i gutentag\n"
	printf "\n"
	printf "Finalize example: $0 -f\n"	
	printf "\n"
	exit 1
}

FINIT='false'
INIT='false'
UMBRELLA='false'

# Script options 
optstring=":i:r:fuh"
while getopts ${optstring} arg; do
	case ${arg} in 
		f)
			FINIT='true'
			;;
		i)
			INIT='true'
			APP_NAME=${OPTARG};
			;;
		r)
			INIT='true'
			APP_CONTAINER_ROOT=${OPTARG}
			;;
		u)
			INIT='true'
			UMBRELLA='true'
			;;
		h)
			usage
			;;
		:)
			printf "Missing required value for -$OPTARG\n"
			usage
			;;
		\?)
			printf "Invalid option... -${OPTARG}\n"
			usage
			;;
	esac
done


# Main function to run script operations
main() {
	
	if [[ ${FINIT} == true ]]; then
		finalize

	elif  [[ ${INIT} == true ]]; then 
		initialize
	fi
}

# Generate a random 14 character password
gen_rand_pass() {
	if [[ "$OSTYPE" == "darwin"* ]]; then 
		PPWD=$(date +%s | shasum -a 256 | base64 | head -c14)

	elif [[ "$OSTYPE" == "linux-gnu"* ]]; then
		PPWD=$(date +%s | sha256sum | base64 | head -c14)

	fi
}

# Generate the docker environment file if it does not exist
gen_env_file() {
	if [ ! -f $ENV_FILE ]; then

cat > $ENV_FILE <<EnvFile
# app variables
APP_CONTAINER_ROOT=$APP_CONTAINER_ROOT
APP_NAME=$APP_NAME
MIX_ENV=$MIX_ENV
WORKINGDIR=$APP_CONTAINER_ROOT
UMBRELLA=$UMBRELLA
EnvFile

	else
		printf "Environment file is already existing.\n"
		exit 1
	fi
}

gen_db_secret_file() {
	# Generate a random password for Postgres
	gen_rand_pass

	if [ ! -f $DB_SECRET_FILE ]; then

cat > $DB_SECRET_FILE <<DbFile
$PPWD
DbFile
	else
		printf "DB secret file is already existing.\n"
		exit 1
	fi
}

# Report an error when sed fails
sed_error() {
	printf "Exiting, failed to update... $update_file. Please file a \
bug report.\n"
	exit 1
}


# Initialize the Phoenix Framework project
initialize() {
	if [ -n $APP_NAME ]; then 
		
		printf "Initializing Phoenix Framework project...\n"
		printf "Application container root............... $APP_CONTAINER_ROOT\n"
		printf "Application name......................... $APP_NAME\n"
		
		# Generate the initial docker environment file
		gen_env_file

		# Generate database secret
		gen_db_secret_file

		if [[ ${UMBRELLA} == true ]]; then
			printf "Running phx.new umbrella...\n"
			docker compose run --rm app mix phx.new --umbrella --install $APP_NAME --binary-id
		else
			printf "Running phx.new...\n"
			docker compose run --rm app mix phx.new --install $APP_NAME --binary-id
		fi
	else
		usage
	fi
}


# Finalize the Phoenix Framework configuration and call mix ecto.create
finalize() {
	if [ ! -f "$ENV_FILE" ]; then 
		usage
	else
		lc=0
		while IFS=$'=' read -r avar aval; do

			if [[ "$avar" == "APP_CONTAINER_ROOT"* ]]; then 
				APP_CONTAINER_ROOT=$aval	
			fi
			if [[ "$avar" == "APP_NAME"* ]]; then
				APP_NAME=$aval
			fi
			if [[ "$avar" == "UMBRELLA"* ]]; then
			       UMBRELLA=$aval
			fi	       
			if [[ "$avar" == "MIX_ENV"* ]]; then
				MIX_ENV=$aval
			fi

		done < $ENV_FILE

		if [ ! -f "$DB_SECRET_FILE" ]; then
			usage
		else
			while read -r secret; do
				PPWD="$secret"
			done < $DB_SECRET_FILE
		fi

		# Set the docker working directory
		# This is the directory where the app will live in the 
		# docker container
		if [[ ${UMBRELLA} == true ]]; then
			APP_NAME="$APP_NAME"_umbrella
		fi

		WORKINGDIR="$APP_CONTAINER_ROOT/$APP_NAME"

		# Password format for database "<password>",
		DB_PPWD=\"$PPWD\",

		# Configure dev.exs for docker
		update_file="src/$APP_NAME/config/dev.exs"
		sed -i '' -e "s|\(password: \).*|\1"$DB_PPWD"|" \
			-e 's|"localhost"|"db"|' \
			-e 's|127, 0, 0, 1|0, 0, 0, 0|' $update_file

		# sed varies between operating systems, check if it failed
		if [ $? -gt 0 ]; then
			sed_error
		fi

		# Configure test.exs for docker
		update_file="src/$APP_NAME/config/test.exs"
		sed -i '' -e "s|\(password: \).*|\1"$DB_PPWD"|" \
			-e 's|"localhost"|"db"|' \
			-e 's|127, 0, 0, 1|0, 0, 0, 0|' $update_file

		# sed varies between operating systems, check if it failed
		if [ $? -gt 0 ]; then
			sed_error
		fi

		# Update the WORKINGDIR in the env file
		update_file=$ENV_FILE
		sed -i '' -e "s|\(WORKINGDIR=\).*|\1"$WORKINGDIR"|" \
			$update_file

		# sed varies between operating systems, check if it failed
		if [ $? -gt 0 ]; then
			sed_error	
		fi
		
		# Run mix ecto.create
		cd "src/$APP_NAME"
		printf "Running mix ecto.create...\n"
		docker compose run --rm app mix ecto.create


		# Start the application
		printf "Running docker compose up; press ctrl-c to stop...\n"
		printf "\n"
		docker compose up
	fi
}

main