Shared library for general BASH scripting

shared_functs.lib

#!/bin/bash

#=================================================================================================#
#shared_functs.lib
#----------
#by: ilobmirt @ 2023_JUL_07
#
#Central location for functions shared among various scripts
#=================================================================================================#

echo "===== INCLUDED SHARED_FUNCTS LIBRARY ====="

#=================================================================================================#
declare -A return_code
return_code[SUCCESS]=0
return_code[GENERAL]=1
return_code[INVALID_USAGE]=2
return_code[CANNOT_EXECUTE]=126
return_code[COMMAND_NOT_FOUND]=127
return_code[INVALID_PARAMETER]=128
return_code[FATAL_ERROR]=128
return_code[OUT_OF_RANGE]=255
export return_code
#=================================================================================================#
function fill_params(){

	local in_search=''
	local in_default=''
	local in_input=()
	local param_val=''
	local is_set=0
	local is_found=0
	local param_index=1
	local param_index_next=0

	#Set params for this function
	for (( param_index = 1 ; param_index <= $# ; param_index++ )) ; do
		param_val=${!param_index}
		param_index_next=$((param_index+1))
		printf "\n\n-----\n%s\n" "INPUT PARAM $param_index = \"${!param_index}\""
		printf "%s\n-----\n\n" "INPUT VALUE $param_index = \"${!param_index_next}\""
		case "${param_val}"
		in
			'--search')
				in_search=${!param_index_next}
				printf "%s\n" "Set search to \"$in_search\""
				param_index=$(( param_index + 1 ))
				;;
			'--default')
				in_default=${!param_index_next}
				printf "%s\n" "Set default val to \"$in_default\""
				param_index=$(( param_index + 1 ))
				;;
			'--input')
				s2l in_input "${!param_index_next}"				
				printf "%s\n" "Set input array to \"${in_input[@]}\""
				param_index=$(( param_index + 1 ))
				;;
			'--var')
				local -n in_var=${!param_index_next}
				printf "%s\n" "Set return var to \"$in_var\""
				is_set=1
				param_index=$(( param_index + 1 ))
				;;
		esac
	done
	
	#Now we set the value of in_var
	if [[ $is_set -eq 0 ]] ; then
		#Not set
		printf "in_var has not been set\n"
	else
		#Set
		printf "in_var has been set\n"
		
		if [[ ! -z "$in_search" ]] && [[ ! -z "$in_input" ]] ; then
			#Set
			printf "Search: \"$in_search\"\n"
			printf "Input: \"$in_input\"\n"
			
			param_index=0
			for (( param_index = 0 ; param_index <= ${#in_input[@]} ; param_index++ )) ; do
				param_index_next=$((param_index+1))
				param_val=${in_input[param_index]}
				printf "SEARCH PARAM $param_index = \"$param_val\"\n"
				if [[ "$param_val" = "--$in_search" ]] ; then
					in_var=${in_input[param_index_next]}
					is_found=1
					break
				fi
			done
			
			#Set Default if not found
			if [[ $is_found -eq 0 ]] ; then
				in_var=$in_default
			fi
			
		else
			#Not Set
			printf "Search and Input both need to be set\n"
		fi
	fi
	
}
export -f fill_params
#=================================================================================================#
function l2s(){
	#Convert a list into a single string separated by ';;;'
	local main_input="$@"
	local main_output=$( echo "${main_input}" | sed 's#\(\".*\"\|\S*\)#\1!!!#g;s#"##g;s#!!! *#!!!#g;s#!!!$##' )
	printf "%s" "${main_output}"
}
export -f l2s
#=================================================================================================#
function s2l(){
	local -n in_var=$1
	local main_input="$2"
	local main_output=$(echo "${main_input}" | sed 's#!!!#\n#g')
	local calc_list=()

	readarray -t calc_list <<<$main_output

	in_var=( "${calc_list[@]}" )

}
export -f s2l
#=================================================================================================#
function sync_file(){

	local file_target="$1"
	local file_contents="$2"
	local did_update_var="$3"
	if ! [ ${#did_update_var} -eq 0 ]; then
		local -n did_update=$3
	else
		local did_update=0
	fi
	local check_file_contents=''
	
	if [ -f "$file_target" ] ; then
		echo "Target file $file_target found!"
		check_file_contents=$(cat "$file_target")
		if [ "$check_file_contents" != "$file_contents" ] ; then
			echo "Target file $file_target needs an update! Updating!"
			echo "$file_contents" | sudo tee "$file_target" > /dev/null
			did_update=1
		else
			echo "Target file $file_target seems up to date."
			did_update=0
		fi
	else
		echo "Target file $file_target not found"
		did_update=0
	fi

}
export -f sync_file
#=================================================================================================#
function rem_ssh_cmd(){

  local func_input="$(l2s "$@")"
  local target_user=''
  local target_host=''
  local target_dir=''
  local target_cmd=''
  local out_result=${return_code[SUCCESS]}

  fill_params --input "${func_input}" --var target_user --search user --default 'root' > /dev/null
  fill_params --input "${func_input}" --var target_host --search host --default '127.0.0.1' > /dev/null
  fill_params --input "${func_input}" --var target_dir --search dir --default "/home/${target_user}" > /dev/null
  fill_params --input "${func_input}" --var target_cmd --search cmd --default 'ls' > /dev/null

  ssh -t ${target_user}@${target_host} "cd ${target_dir} && ${target_cmd}"

  return $out_result

}
export -f rem_ssh_cmd
#=================================================================================================#
function setup_packages(){
	sudo apt-get update
	local installed_packages=$(apt list --installed)
	local to_install=""
	local does_exist=""
	for input_package in $@
	do
		does_exist=$(echo "$installed_packages" | grep "$input_package/")
		if [ -z "$does_exist" ]; then
			echo "Package $input_package not found, adding to list of packages"
			to_install="$to_install $input_package"
		else
			echo "Package $input_package is already installed"
		fi
	done

	if [ ! -z "$to_install" ]; then
		echo "Installing $to_install"
		sudo apt-get install$to_install -y
	else
		echo "Nothing found to install"
	fi
}
export -f setup_packages
#=================================================================================================#
function set_hostname(){
	local target_hostname="$1"
	local original_hostname=$(hostname)
	local hosts_file_contents=$(sudo cat /etc/hosts)

	printf "  -  (1/3) Updating /etc/hostname ...\n"
	echo "${target_hostname}" | sudo tee /etc/hostname
	printf "  -  (2/3) Updating /etc/hosts\n"
	hosts_file_contents=$(echo "${hosts_file_contents}" | sed "s/${original_hostname}/${target_hostname}/g")
	sync_file "/etc/hosts" "${hosts_file_contents}"
	printf "  -  (3/3) Setting host name to \'${target_hostname}\'\n "
	sudo hostname ${target_hostname}

}
export -f set_hostname
#=================================================================================================#
function github_ssh_key(){

	local func_input="$(l2s "$@")"
	local out_result=${return_code[SUCCESS]}
	local local_user=$(id -u -n)
	local target_user=''
	local target_github=''
	local target_method=''

	fill_params --input "${func_input}" --var target_user --search user --default "${local_user}" > /dev/null
	fill_params --input "${func_input}" --var target_github --search github --default "$1" > /dev/null
	fill_params --input "${func_input}" --var target_method --search method --default 'add' > /dev/null

	#CONDITION #1 - Github Account must be defined
	if [[ "${target_github}" == '' ]]; then
			local out_txt=$(cat <<EOF
╔═════════════════════════╗
║github_ssh_key - FAILURE:║
╚═════════════════════════╝
	[INVALID_USAGE]. Github Account not defined.

    ▻ EXAMPLE: github_ssh_key ilobmirt
       ▔▔▔▔▔▔▔▔
EOF
)

		printf "%s\n" "${out_txt}"
		out_result=${return_code[INVALID_USAGE]}
		return $out_result
	fi

	#CONDITION #2 - Method needs to be [add|rem|remove]
	local method_filter=('add' 'rem' 'remove')
	if ! [[ ${method_filter[*]} =~ ${target_method} ]]; then
		local out_txt=$(cat <<EOF
╔═════════════════════════╗
║github_ssh_key - FAILURE:║
╚═════════════════════════╝
	[INVALID_USAGE]. Invalid method \"${target_method}\"
	Acceptable methods are the following...
	$(printf "\t[%s]\n" "${method_filter[@]}")

    ▻ EXAMPLE: github_ssh_key --github ilobmirt --method ${method_filter[0]}
       ▔▔▔▔▔▔▔▔
EOF
)
		printf "%s\n" "${out_txt}"
		out_result=${return_code[INVALID_USAGE]}
		return $out_result
	fi

	#CONDITION #3 - User account must have a home directory
	if ! [ -d "/home/${target_user}" ]; then
		local out_txt=$(cat <<EOF
╔═════════════════════════╗
║github_ssh_key - FAILURE:║
╚═════════════════════════╝
	[INVALID_PARAMETER]. The user account \"${target_user}\" does not appear to have a home directory.
EOF
)
		out_result=${return_code[INVALID_PARAMETER]}
		return $out_result
	fi

	#After all these checks, lets get the key
	local key_comment="${target_github}@github_ssh_key"
	local github_key="$(curl https://github.com/${target_github}.keys) ${key_comment}"

	#Pull the contents of /home/${target_user}/.ssh/authorized_keys, create if it doesn't exist
	if ! [ -d "/home/${target_user}/.ssh" ]; then
		sudo mkdir "/home/${target_user}/.ssh"
		sudo chmod 700 "/home/${target_user}/.ssh"
		sudo chown ${target_user}:${target_user} "/home/${target_user}/.ssh"
	fi
	if ! [ -f "/home/${target_user}/.ssh/authorized_keys" ]; then
		sudo touch "/home/${target_user}/.ssh/authorized_keys"
		sudo chmod 600 "/home/${target_user}/.ssh/authorized_keys"
		sudo chown ${target_user}:${target_user} "/home/${target_user}/.ssh/authorized_keys"
	fi
	local auth_key_file=$(sudo cat "/home/${target_user}/.ssh/authorized_keys")

	case "${target_method}" in
		'rem' | 'remove')
			auth_key_file=$(echo "${auth_key_file}" | sed "/${key_comment}/d")
			;;
		'add')
			auth_key_file=$(echo "${auth_key_file}" | sed -r "s/^(ssh-).*(${key_comment})$/${github_key}/g")
			if [[ "$(echo "${auth_key_file}" | grep "${key_comment}" )" == '' ]]; then
				auth_key_file=$(printf "${auth_key_file}\n${github_key}")
			fi
			;;
		*)
			;;
	esac

	#Now to push the changes to the actual file
	sync_file "/home/${target_user}/.ssh/authorized_keys" "${auth_key_file}"

	return $out_result

}
export -f github_ssh_key
#=================================================================================================#