Check memory requirements to prevent install/upgrade/restore processes from being killed

scripts/_common.sh

@@ -27,6 +27,47 @@ exec_as() {
   fi
 }
 
+# Returns true if a swap partition is enabled, false otherwise
+# usage: is_swap_present
+is_swap_present() {
+  [ $(awk '/^SwapTotal:/{print $2}' /proc/meminfo)  -gt 0 ]
+}
+
+# Returns true if swappiness higher than 50
+# usage: is_swappiness_sufficient
+is_swappiness_sufficient() {
+  [ $(cat /proc/sys/vm/swappiness)  -gt 50 ]
+}
+
+# Returns true if specified free memory is available (RAM + swap)
+# usage: is_memory_available MEMORY (in bytes)
+is_memory_available() {
+  local needed_memory=$1
+  local freemem="$(awk '/^MemAvailable:/{print $2}' /proc/meminfo)"
+  local freeswap="$(awk '/^SwapFree:/{print $2}' /proc/meminfo)"
+  [ $(($freemem+$freeswap)) -gt $needed_memory ]
+}
+
+# Checks discourse install memory requirements
+# terminates installation if requirements not met
+check_memory_requirements() {
+  if ! is_swap_present ; then
+    ynh_die "You must have a swap partition in order to install and use this application"
+  elif ! is_swappiness_sufficient ; then
+    ynh_die "Your swappiness must be higher than 50; please see https://en.wikipedia.org/wiki/Swappiness"
+  elif ! is_memory_available 1000000 ; then
+    ynh_die "You must have a minimum of 1Gb available memory (RAM+swap) for the installation"
+  fi
+}
+# Checks discourse upgrade memory requirements
+# Less requirements as the software is already installed and running
+# terminates upgrade if requirements not met
+check_memory_requirements_upgrade() {
+  if ! is_memory_available 400000 ; then
+    ynh_die "You must have a minimum of 400Mb available memory (RAM+swap) for the upgrade"
+  fi
+}
+
 #=================================================
 # POSTGRES HELPERS
 #=================================================

scripts/install

@@ -15,7 +15,7 @@ source _common.sh
 #=================================================
 
 ynh_clean_setup () {
-# Nettoyage des résidus d'installation non pris en charge par le script remove.
+# Nettoyage des résidus d'installation non pris en charge par le script remove.
 	ynh_clean_check_starting_systemd
 }
 ynh_abort_if_errors	# Stop script if an error is detected
@@ -47,6 +47,9 @@ ynh_webpath_available $domain $path_url
 # Register (book) web path
 ynh_webpath_register $app $domain $path_url
 
+# Check memory requirements
+check_memory_requirements
+
 #=================================================
 # STORE SETTINGS FROM MANIFEST
 #=================================================

scripts/restore

@@ -41,6 +41,9 @@ ynh_webpath_available $domain $path_url \
 test ! -d $final_path \
 	|| ynh_die "There is already a directory: $final_path "
 
+	# Check memory requirements
+	check_memory_requirements
+
 #=================================================
 # STANDARD RESTORATION STEPS
 #=================================================

scripts/upgrade

@@ -35,6 +35,9 @@ admin=$(ynh_app_setting_get $app admin)
 db_name=$(ynh_app_setting_get $app db_name)
 db_pwd=$(ynh_app_setting_get $app db_pwd)
 
+# Check memory requirements
+check_memory_requirements_upgrade
+
 #=================================================
 # BACKUP BEFORE UPGRADE
 #=================================================