(unsecure, easy) Makefile alternative for sh

run.sh

#!/bin/sh
set -e

DEFAULT=help

#########################
## your functions here ##
#                       #

help() {
    echo "=================== help ========================"
    echo "help - run this help"
    echo "build - builds something via Makefile, requires make"
    echo "checkout - checkout repo and submodules"
    echo "deploy_dev - deploy something (dummy)"
    echo "================================================="
}

checkout() {
	git checkout develop
	git submodule update --recursive --remote
}

build () {
	# this requires make, check if installed
	check_command_exists make
	# also check if Makefile exists
	check_file_exists ./Makefile
	# then build
	make build
}

deploy_dev() {
    	DEV_HOSTS="host1.my.domain, host2.my.domain"
    	iterate_over_and_run debug $DEV_HOSTS
}

#                         #
## end of your functions ##
###########################

################################
## your helper functions here ##
#                              #

iterate_over_and_run() {
    #param1: method
    #param2: array

    echo "function: ${1}"
    echo "array: ${@:2}"

    array_to_iterate_over=${@:2}

    if [ "x${1}" == "x" ]; then
        echo "missing method and array"
        return
    fi;

    for i in ${array_to_iterate_over//,/ }
    do
        $1 $i
    done
}

check_command_exists() {
    if ! command -v $1 &> /dev/null
    then
        echo "$1 could not be found"
        exit
    fi
}

check_file_exists() {
    if [ ! -f "$1" ]; then
        echo "$1 does not exist."
        exit 1
    fi
}

debug() {
    echo "debug: $1"
}

#                                #
## end of your helper functions ##
##################################

run() {
    if [ -e .env ]; then
        echo "found .env, sourcing it"
        . ./.env
    fi;

    # source run file
    . ./run.sh --source-only
    
    # run default function or run defined one
    if [ "x${1}" == "x" ]; then
        echo "run default: $DEFAULT"
        $DEFAULT
    else
        $@ "${@:2}"
    fi;
}


# this prevents running when sourcing
if [ "${1}" != "--source-only" ]; then
    run "${@}"
fi

# References:
# https://stackoverflow.com/questions/12815774/importing-functions-from-a-shell-script
# https://stackoverflow.com/questions/19331497/set-environment-variables-from-file-of-key-value-pairs
# https://stackoverflow.com/questions/27702452/loop-through-a-comma-separated-shell-variable
# https://stackoverflow.com/questions/592620/how-can-i-check-if-a-program-exists-from-a-bash-script