Merge branch '11-set-up-the-swap-file' into 'master'

Resolve "Set up the swap file for the system with user specified size and default size"

Closes #11

See merge request icaotix/linux-tools!9

modules/swap/__init__.py

@@ -0,0 +1,5 @@
+from .module import SwapModule
+
+
+def get_module():
+    return SwapModule()

modules/swap/module.py

@@ -0,0 +1,129 @@
+import subprocess
+from AbstractModule import AbstractModule
+from PyInquirer import prompt
+
+
+class SwapModule(AbstractModule):
+
+    def __init__(self):
+        super().__init__()
+
+    def run(self):
+        actions = {
+            "Create/Resize temp. swap": self._create_resize_swap,
+            "Create/Resize persistent swap": self._create_resize_persistent_swap,
+            "Delete swap": self._delete_swap,
+            "Make temp. swap persistent": self._make_swap_persistent,
+            "Get swap location": self._get_swap_location,
+            "Get swap size": self._get_swap_size,
+            "Show swapiness": self._show_swapiness,
+            "Adjust temp. swapiness": self._adjust_swapiness_temp
+        }
+        menu = [
+            {
+                'type': 'list',
+                'message': 'Select action',
+                'name': 'action',
+                'choices': list(map(lambda x: {"name": x}, actions.keys()))
+            }
+        ]
+        selected_action = prompt(menu)['action']
+        actions[selected_action]()
+
+    def _create_resize_persistent_swap(self):
+        self._create_resize_swap()
+        self._make_swap_persistent()
+
+    def _get_swap_location(self):
+        output_swaps = subprocess.check_output(['cat', '/proc/swaps']).decode("UTF-8")
+        try:
+            swap_location = output_swaps.split()[5]
+            print("Swap is located here:", swap_location)
+            return swap_location
+        except IndexError:
+            print("Swap file doesn´t exist!")
+            return None
+
+    def _get_swap_size(self):
+        swap_size = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
+        try:
+            swap_size = swap_size.split()[7]
+            print("Swap is {}b big!".format(swap_size))
+        except IndexError:
+            print("Swap file doesn´t exist!")
+
+    def _create_resize_swap(self):
+        output_swapon = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
+        if output_swapon:
+            swap_size = subprocess.check_output(['swapon', '--show']).decode("UTF-8")
+            swap_size = swap_size.split()[7]
+            print("")
+            print("Swap already installed! You can resize it!")
+            print("Curr. swap size: {}b".format(swap_size))
+            resize = input("How big should your swap become (numbers in Gigabyte)? ")
+            resize_swapfile = "sudo swapoff /swapfile && " + \
+                              "sudo fallocate -l {}G /swapfile && ".format(resize) + \
+                              "sudo mkswap /swapfile && " + \
+                              "sudo swapon /swapfile"
+            subprocess.call(resize_swapfile, shell=True)
+            output_free = subprocess.check_output(['free', '-h']).decode("UTF-8")
+            print(output_free.strip())
+
+        else:
+            size = input("How big should the swap be (numbers in Gigabyte)? ")
+            create_swapfile = "sudo fallocate -l {}G /swapfile && ".format(size) + \
+                              "sudo chmod 600 /swapfile && " + \
+                              "sudo mkswap /swapfile && " + \
+                              "sudo swapon /swapfile"
+            subprocess.call(create_swapfile, shell=True)
+
+            output_free = subprocess.check_output(['free', '-h']).decode("UTF-8")
+            print(output_free.strip())
+
+    def _make_swap_persistent(self):
+        swap_location = self._get_swap_location()
+        if swap_location is None:
+            print("Swap file doesn't exist!")
+            return
+        backup_fstab = "sudo cp /etc/fstab /etc/fstab.bak"
+        enable_persistence = "echo '{} none swap sw 0 0' | sudo tee -a /etc/fstab".format(swap_location)
+        subprocess.call(backup_fstab, shell=True)
+        subprocess.call(enable_persistence, shell=True)
+        print("Swap is now persistent!")
+
+    def _show_swapiness(self):
+        get_swapiness = "cat /proc/sys/vm/swappiness"
+        subprocess.call(get_swapiness, shell=True)
+
+    def _adjust_swapiness_temp(self):
+        options = {
+            "Light": 25,
+            "Default": 60,
+            "Aggressive": 100
+        }
+        menu = [
+            {
+                'type': 'list',
+                'message': 'Select action',
+                'name': 'action',
+                'choices': list(map(lambda x: {"name": x}, options.keys()))
+            }
+        ]
+        selected_swapiness = prompt(menu)['action']
+
+        adjust = "sudo sysctl vm.swappiness=" + str(options[selected_swapiness])
+        subprocess.call(adjust, shell=True)
+        print("Temporary swapiness is " + str(options[selected_swapiness]))
+
+    def _delete_swap(self):
+        swap_location = self._get_swap_location()
+        if swap_location is None:
+            return
+        disable_swapfile = "sudo swapoff {} && ".format(swap_location) + \
+                           "sudo rm {}".format(swap_location)
+        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())