linux-tools/modules/swap/module.py

import subprocess
from AbstractModule import AbstractModule
from PyInquirer import prompt


class SwapModule(AbstractModule):

    def __init__(self):
        super().__init__()
        self.swap_file = None

    def run(self):

        actions = ["Create/Resize", "Delete", "Get swap location", "Get swap size"]
        menu = [
            {
                'type': 'list',
                'message': 'Select action',
                'name': 'action',
                'choices': list(map(lambda x: {"name": x}, actions))
            }
        ]
        selected_action = prompt(menu)['action']
        if selected_action == "Create/Resize":
            self.create_resize_swap()
        elif selected_action == "Delete":
            self.delete_swap()
        elif selected_action == "Get swap location":
            self.swap_location_check()
        elif selected_action == "Get swap size":
            self.get_swap_size()

    def swap_location_check(self) -> None:
        output_swaps = subprocess.check_output(['cat', '/proc/swaps']).decode("UTF-8")
        li = list(output_swaps.split())
        final_list = li
        try:
            print("Swap is located here:", final_list[5])
            self.swap_file = final_list[5]
        except IndexError:
            print("Swap file doesn´t exist!\n")

    def get_swap_size(self) -> None:
        swap_size = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
        li = list(swap_size.split())
        final_list = li
        try:
            print("Swap is {}b big!".format(final_list[7]))
        except IndexError:
            print("Swap file doesn´t exist!")

    def create_resize_swap(self):
        output_swapon = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
        if not output_swapon:
            size = input("How big should the swap be(numbers in Gigabyte)? ")
            create_swapfile = """sudo fallocate -l {}G /swapfile && 
            sudo chmod 600 /swapfile && 
            sudo mkswap /swapfile && 
            sudo swapon /swapfile""".format(size)
            subprocess.call(create_swapfile, shell=True)

            output_free = subprocess.check_output(['free', '-h']).decode("UTF-8")
            print(output_free.strip())

        else:
            print("")
            print("Swap already installed! You can resize it!")
            resize = input("How big should your swap become(numbers in Gigabyte)? ")
            resize_swapfile = """sudo swapoff /swapfile && 
            sudo fallocate -l {}G /swapfile && 
            sudo mkswap /swapfile && 
            sudo swapon /swapfile""".format(resize)
            subprocess.call(resize_swapfile, shell=True)
            output_free = subprocess.check_output(['free', '-h']).decode("UTF-8")
            print(output_free.strip())

    def delete_swap(self):
        self.swap_location_check()
        disable_swapfile = """sudo swapoff {0} && 
        sudo rm {0}""".format(self.swap_file)

        subprocess.call(disable_swapfile, shell=True)
        output_swapon = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
        output_free = subprocess.check_output(['free', '-h']).decode("UTF-8")
        if not output_swapon:
            print("Swap deleted!")
            print(output_free.strip())