From a54ec11ae7f068898be6408581a86a4bf0b28fac Mon Sep 17 00:00:00 2001 From: tituspijean Date: Thu, 30 May 2024 22:11:57 +0200 Subject: [PATCH] Implement config panel for swap management --- helpers/helpers.v1.d/hardware | 102 ++++++++++++++++++++++++++++++++++ hooks/conf_regen/53-swap | 29 ++++++++++ share/config_global.toml | 23 ++++++++ src/settings.py | 6 ++ 4 files changed, 160 insertions(+) create mode 100755 hooks/conf_regen/53-swap diff --git a/helpers/helpers.v1.d/hardware b/helpers/helpers.v1.d/hardware index 091f023f6..bab855c42 100644 --- a/helpers/helpers.v1.d/hardware +++ b/helpers/helpers.v1.d/hardware @@ -103,3 +103,105 @@ ynh_require_ram() { return 0 fi } + +# Add swap +# +# usage: ynh_add_swap --size=SWAP in MB +# | arg: -s, --size= - Amount of SWAP to add in MB. +ynh_add_swap () { + # Declare an array to define the options of this helper. + declare -Ar args_array=( [s]=size= ) + local size + # Manage arguments with getopts + ynh_handle_getopts_args "$@" + + local swap_max_size=$(( $size * 1024 )) + + local free_space=$(df --output=avail / | sed 1d) + # Because we don't want to fill the disk with a swap file, divide by 2 the available space. + local usable_space=$(( $free_space / 2 )) + + SD_CARD_CAN_SWAP=${SD_CARD_CAN_SWAP:-0} + + # Swap on SD card only if it's is specified + if ynh_is_main_device_a_sd_card && [ "$SD_CARD_CAN_SWAP" == "0" ] + then + ynh_print_warn --message="The main mountpoint of your system '/' is on an SD card, swap will not be added to prevent some damage to it. If you still want activate the swap, you can relaunch the command preceded by 'SD_CARD_CAN_SWAP=1'" + return + fi + + # Compare the available space with the size of the swap. + # And set a acceptable size from the request + if [ $usable_space -ge $swap_max_size ] + then + local swap_size=$swap_max_size + elif [ $usable_space -ge $(( $swap_max_size / 2 )) ] + then + local swap_size=$(( $swap_max_size / 2 )) + elif [ $usable_space -ge $(( $swap_max_size / 3 )) ] + then + local swap_size=$(( $swap_max_size / 3 )) + elif [ $usable_space -ge $(( $swap_max_size / 4 )) ] + then + local swap_size=$(( $swap_max_size / 4 )) + else + echo "Not enough space left for a swap file" >&2 + local swap_size=0 + # Store the swap size + yunohost settings set 'swap.swapfile.swapfile_size' -v ${swap_size} + fi + + # If there's enough space for a swap, and no existing swap here + if [ $swap_size -ne 0 ] && [ ! -e /swap_file ] + then + # Create file + truncate -s 0 /swap_file + + # set the No_COW attribute on the swapfile with chattr + chattr +C /swap_file + + # Preallocate space for the swap file, fallocate may sometime not be used, use dd instead in this case + if ! fallocate -l ${swap_size}K /swap_file + then + dd if=/dev/zero of=/swap_file bs=1024 count=${swap_size} + fi + chmod 0600 /swap_file + # Create the swap + mkswap /swap_file + # And activate it + swapon /swap_file + # Then add an entry in fstab to load this swap at each boot. + echo -e "/swap_file swap swap defaults 0 0 #Swap added by YunoHost config panel" >> /etc/fstab + # Store the swap size + yunohost settings set 'swap.swapfile.swapfile_size' -v ${swap_size} + fi +} + +ynh_del_swap () { + # If there a swap at this place + if [ -e /swap_file ] + then + # Clean the fstab + sed -i "/#Swap added by YunoHost config panel/d" /etc/fstab + # Desactive the swap file + swapoff /swap_file + # And remove it + rm /swap_file + fi +} + +# Check if the device of the main mountpoint "/" is an SD card +# +# [internal] +# +# return 0 if it's an SD card, else 1 +ynh_is_main_device_a_sd_card () { + local main_device=$(lsblk --output PKNAME --noheadings $(findmnt / --nofsroot --uniq --output source --noheadings --first-only)) + + if echo $main_device | grep --quiet "mmc" && [ $(tail -n1 /sys/block/$main_device/queue/rotational) == "0" ] + then + return 0 + else + return 1 + fi +} diff --git a/hooks/conf_regen/53-swap b/hooks/conf_regen/53-swap new file mode 100755 index 000000000..b3e6f89dc --- /dev/null +++ b/hooks/conf_regen/53-swap @@ -0,0 +1,29 @@ +#!/bin/bash + +set -e + +. /usr/share/yunohost/helpers + +do_pre_regen() { +} + +do_post_regen() { + + swapfile_enabled="$(yunohost settings get 'swap.swapfile.swapfile_enabled')" + swapfile_size="$(yunohost settings get 'swap.swapfile.swapfile_size')" + + if [ "${swapfile_enabled}" == "True" ]; then + # If a swapfile is requested + if [ $(stat -c%s /swap_file) -ne $swapfile_size ]; then + # Let's delete it first if it is not of the requested size + ynh_del_swap + fi + # create the swapfile + ynh_add_swap --size=$swapfile_size + else + # If not, make sure it is deleted + ynh_del_swap + fi +} + +do_$1_regen ${@:2} diff --git a/share/config_global.toml b/share/config_global.toml index 40b71ab19..54a80ede4 100644 --- a/share/config_global.toml +++ b/share/config_global.toml @@ -169,3 +169,26 @@ name = "Other" choices.ipv4 = "IPv4 Only" choices.ipv6 = "IPv6 Only" default = "both" +[swap] +name = "Swap" + [swap.swapfile] + name = "Swap file configuration" + [swap.swapfile.swapfile_enabled] + ask = "Do you need to create a swap file?" + help = "A swap file will extend the available RAM by using some of your storage space." + type = "boolean" + default = false + visible = "swapfile_enabled" + + [swap.swapfile.swapfile_warning] + ask = "Absolutely do not create a swap file if your root partition is on a SD card!" + help = "The intensive writing on the SD card will degrade it fast." + type = "alert" + style = "danger" + + [swap.swapfile.swapfile_size] + ask = "How many megabytes should the swap file be?" + help = "Only integers are accepted. Beware, if you reduce its current size, you may crash your server." + type = "number" + default = 1 + visible = "swapfile_enabled" diff --git a/src/settings.py b/src/settings.py index abe1a8f13..7650f8d53 100644 --- a/src/settings.py +++ b/src/settings.py @@ -366,3 +366,9 @@ def reconfigure_dovecot(setting_name, old_value, new_value): regen_conf(names=["dovecot"]) command = ["apt-get", "-y", "remove", dovecot_package] subprocess.call(command, env=environment) + +@post_change_hook("swapfile_enabled") +@post_change_hook("swapfile_size") +def reconfigure_swapfile(setting_name, old_value, new_value): + if old_value != new_value: + regen_conf(names=["swap"])