Fixes and enhancements for swap management

helpers/helpers.v1.d/hardware

@@ -106,8 +106,8 @@ ynh_require_ram() {
 
 # Add swap
 #
-# usage: ynh_add_swap --size=SWAP in MB
+# usage: ynh_add_swap --size=SWAP in MiB
-# | arg: -s, --size= - Amount of SWAP to add in MB.
+# | arg: -s, --size= - Amount of SWAP to add in MiB.
 ynh_add_swap () {
     # Declare an array to define the options of this helper.
     declare -Ar args_array=( [s]=size= )
@@ -121,7 +121,7 @@ ynh_add_swap () {
     # 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=${SD_CARD_CAN_SWAP:-0}
+    SD_CARD_CAN_SWAP=${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" ]
@@ -134,21 +134,19 @@ ynh_add_swap () {
     # And set a acceptable size from the request
     if [ $usable_space -ge $swap_max_size ]
     then
-        local swap_size=$swap_max_size
+        swap_size=$swap_max_size
     elif [ $usable_space -ge $(( $swap_max_size / 2 )) ]
     then
-        local swap_size=$(( $swap_max_size / 2 ))
+        swap_size=$(( $swap_max_size / 2 ))
     elif [ $usable_space -ge $(( $swap_max_size / 3 )) ]
     then
-        local swap_size=$(( $swap_max_size / 3 ))
+        swap_size=$(( $swap_max_size / 3 ))
     elif [ $usable_space -ge $(( $swap_max_size / 4 )) ]
     then
-        local swap_size=$(( $swap_max_size / 4 ))
+        swap_size=$(( $swap_max_size / 4 ))
     else
         echo "Not enough space left for a swap file" >&2
-        local swap_size=0
+        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
@@ -158,7 +156,8 @@ ynh_add_swap () {
         truncate -s 0 /swap_file
 
         # set the No_COW attribute on the swapfile with chattr
-        chattr +C /swap_file
+        # let's not fail here, as some filesystems like ext4 do not support COW
+        chattr +C /swap_file || true
 
         # 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
@@ -172,8 +171,6 @@ ynh_add_swap () {
         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
 }
 

hooks/conf_regen/53-swap

@@ -1,27 +1,29 @@
 #!/bin/bash
 
-set -e
+source /usr/share/yunohost/helpers
-
-. /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 [ ${swapfile_enabled} -eq 1 ]; then
         # If a swapfile is requested
-        if [ $(stat -c%s /swap_file) -ne $swapfile_size ]; then
+        if [ -f /swap_file ] && [ $(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
+            ynh_print_info --message="Deleting swap first..."
+            ynh_del_swap
         fi
         # create the swapfile
+        ynh_print_info --message="Attempting to create $swapfile_size MB swap..."
         ynh_add_swap --size=$swapfile_size
+        ynh_print_info --message="A $((swap_size / 1024)) MB swap has been created."
     else
         # If not, make sure it is deleted
+        ynh_print_info --message="Deleting swap..."
         ynh_del_swap
     fi
 }

share/config_global.toml

@@ -173,22 +173,21 @@ name = "Other"
 name = "Swap"
     [swap.swapfile]
     name = "Swap file configuration"
+        [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 = "warning"
+
         [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?"
+        ask = "How many Mebibytes should the swap file be?"
-        help = "Only integers are accepted. Beware, if you reduce its current size, you may crash your server."
+        help = "Only integers are accepted ( 1 MiB = 1024 B). Beware, if you reduce its current size, you may crash your server."
         type = "number"
-        default = 1
+        default = 1024
         visible = "swapfile_enabled"