diff --git a/scripts/upgrade b/scripts/upgrade
index 2dffa9f..bbaf187 100755
--- a/scripts/upgrade
+++ b/scripts/upgrade
@@ -1,59 +1,133 @@
 #!/bin/bash
 
-# Exit on command errors and treat unset variables as an error
-set -eu
+#=================================================
+# GENERIC START
+#=================================================
+# IMPORT GENERIC HELPERS
+#=================================================
+
+source _common.sh
+source /usr/share/yunohost/helpers
+
+#=================================================
+# LOAD SETTINGS
+#=================================================
 
-# See comments in install script
 app=$YNH_APP_INSTANCE_NAME
 
-# Source YunoHost helpers
-source /usr/share/yunohost/helpers
+domain=$(ynh_app_setting_get $app domain)
+path_url=$(ynh_app_setting_get $app path)
+admin=$(ynh_app_setting_get $app admin)
+is_public=$(ynh_app_setting_get $app is_public)
+final_path=$(ynh_app_setting_get $app final_path)
+port=$(ynh_app_setting_get $app port)
+db_name=$(ynh_app_setting_get $app db_name)
+
+#=================================================
+# ENSURE DOWNWARD COMPATIBILITY
+#=================================================
+
+if [ "$is_public" = "Yes" ]; then
+	ynh_app_setting_set $app is_public 1	# Fix is_public as a boolean value
+	is_public=1
+elif [ "$is_public" = "No" ]; then
+	ynh_app_setting_set $app is_public 0
+	is_public=0
+fi
+
+if [ -z $db_name ]; then	# If db_name doesn't exist, create it
+	db_name=$(ynh_sanitize_dbid $app)
+	ynh_app_setting_set $app db_name $db_name
+fi
+
+#=================================================
+# CHECK THE PATH
+#=================================================
+
+# Normalize the URL path syntax
+path_url=$(ynh_normalize_url_path $path_url)
+
+#=================================================
+# STANDARD UPGRADE STEPS
+#=================================================
+# DOWNLOAD, CHECK AND UNPACK SOURCE
+#=================================================
+
+# Download, check integrity, uncompress and patch the source from app.src
+ynh_setup_source "$final_path"
+
+#=================================================
+# NGINX CONFIGURATION
+#=================================================
+
+# Create a dedicated nginx config
+ynh_nginx_config
 
-# Retrieve app settings
-domain=$(ynh_app_setting_get "$app" domain)
-path_url=$(ynh_app_setting_get "$app" path_url)
-admin=$(ynh_app_setting_get "$app" admin)
-is_public=$(ynh_app_setting_get "$app" is_public)
-language=$(ynh_app_setting_get "$app" language)
-
-# Remove trailing "/" for next commands
-path_url=${path_url%/}
-
-# Copy source files
-src_path=/var/www/$app
-sudo mkdir -p $src_path
-sudo cp -a ../sources/. $src_path
-
-# Set permissions to app files
-# you may need to make some file and/or directory writeable by www-data (nginx user)
-sudo chown -R root: $src_path
-
-# Modify Nginx configuration file and copy it to Nginx conf directory
-nginx_conf=../conf/nginx.conf
-sed -i "s@YNH_WWW_PATH@$path_url@g" $nginx_conf
-sed -i "s@YNH_WWW_ALIAS@$src_path/@g" $nginx_conf
-# If a dedicated php-fpm process is used:
-#
-# sed -i "s@YNH_WWW_APP@$app@g" $nginx_conf
-sudo cp $nginx_conf /etc/nginx/conf.d/$domain.d/$app.conf
-
-### PHP (remove if not used) ###
-# If a dedicated php-fpm process is used:
-# # Modify PHP-FPM pool configuration and copy it to the pool directory
-# sed -i "s@YNH_WWW_APP@$app@g" ../conf/php-fpm.conf
-# sed -i "s@YNH_WWW_ALIAS@$src_path/@g" ../conf/php-fpm.conf
-# finalphpconf=/etc/php5/fpm/pool.d/$app.conf
-# sudo cp ../conf/php-fpm.conf $finalphpconf
-# sudo chown root: $finalphpconf
-# sudo chmod 644 $finalphpconf
-# sudo service php5-fpm restart
-### PHP end ###
-
-# If app is public, add url to SSOWat conf as skipped_uris
-if [[ $is_public -eq 1 ]]; then
-  # See install script
-  ynh_app_setting_set "$app" unprotected_uris "/"
+#=================================================
+# CREATE DEDICATED USER
+#=================================================
+
+# Create a system user
+ynh_system_user_create $app
+
+#=================================================
+# PHP-FPM CONFIGURATION
+#=================================================
+
+# Create a dedicated php-fpm config
+ynh_fpm_config
+
+#=================================================
+# SPECIFIC UPGRADE
+#=================================================
+# ...
+#=================================================
+
+# Verify the checksum and backup the file if it's different
+ynh_backup_if_checksum_is_different "$final_path/CONFIG_FILE"
+# Recalculate and store the config file checksum into the app settings
+ynh_store_file_checksum "$final_path/CONFIG_FILE"
+
+#=================================================
+# SETUP LOGROTATE
+#=================================================
+
+# Use logrotate to manage app-specific logfile(s)
+ynh_use_logrotate
+
+#=================================================
+# SETUP SYSTEMD
+#=================================================
+
+# Create a dedicated systemd config
+ynh_systemd_config
+
+#=================================================
+# GENERIC FINALIZATION
+#=================================================
+# SECURE FILES AND DIRECTORIES
+#=================================================
+
+# Set right permissions for curl installation
+sudo chown -R root: $final_path
+
+#=================================================
+# SETUP SSOWAT
+#=================================================
+
+if [ $is_public -eq 0 ]
+then	# Remove the public access
+	ynh_app_setting_delete $app skipped_uris
+fi
+# Make app public if necessary
+if [ $is_public -eq 1 ]
+then
+	# unprotected_uris allows SSO credentials to be passed anyway
+	ynh_app_setting_set $app unprotected_uris "/"
 fi
 
-# Reload nginx service
-sudo service nginx reload
+#=================================================
+# RELOAD NGINX
+#=================================================
+
+sudo systemctl reload nginx